@article {bornstein_pickblue_2024,
	title = {PickBlue: Seismic Phase Picking for Ocean Bottom Seismometers With Deep Learning},
	journal = {Earth and Space Science},
	volume = {11},
	number = {1},
	year = {2024},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2023EA003332},
	month = {11/2023},
	pages = {e2023EA003332},
	abstract = {Detecting phase arrivals and pinpointing the arrival times of seismic phases in seismograms is crucial for many seismological analysis workflows. For land station data, machine learning methods have already found widespread adoption. However, deep learning approaches are not yet commonly applied to ocean bottom data due to a lack of appropriate training data and models. Here, we compiled an extensive and labeled ocean bottom seismometer (OBS) data set from 15 deployments in different tectonic settings, comprising \~{}90,000 P and \~{}63,000 S manual picks from 13,190 events and 355 stations. We propose PickBlue, an adaptation of the two popular deep learning networks EQTransformer and PhaseNet. PickBlue joint processes three seismometer recordings in conjunction with a hydrophone component and is trained with the waveforms in the new database. The performance is enhanced by employing transfer learning, where initial weights are derived from models trained with land earthquake data. PickBlue significantly outperforms neural networks trained with land stations and models trained without hydrophone data. The model achieves a mean absolute deviation of 0.05 s for P-waves and 0.12 s for S-waves, and we apply the picker on the Hikurangi Ocean Bottom Tremor and Slow Slip OBS deployment offshore New Zealand. We integrate our data set and trained models into SeisBench to enable an easy and direct application in future deployments.},
	keywords = {machine learning, OBS seismicity database, ocean bottom seismometer, onset determination, phase picking},
	issn = {2333-5084},
	doi = {10.1029/2023EA003332},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023EA003332},
	author = {Bornstein, T. and Lange, D. and M{\"u}nchmeyer, J. and Woollam, J. and Rietbrock, A. and Barcheck, G. and Grevemeyer, I. and Tilmann, F.}
}
@article {morton_cascadia_2023,
	title = {Cascadia Subduction Zone Fault Heterogeneities From Newly Detected Small Magnitude Earthquakes},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {128},
	number = {6},
	year = {2023},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2023JB026607},
	month = {05/2023},
	pages = {e2023JB026607},
	abstract = {The Cascadia subduction zone (CSZ) is known to host M9 megathrust ruptures; however, no such event has occurred in historical observation. The distribution and characteristics of small- to moderate-sized earthquakes can be used to determine the behavior of the megathrust fault but are notably absent offshore the CSZ due to the distance from onshore seismometers. We use automated subspace detection coupled with an onshore-offshore seismic deployment to find small-magnitude earthquakes in the offshore seismogenic zone and analyze their locations in the context of interseismic locking and seismogenic zone extent. We detected and located 5,282 earthquakes, 4,096 of which had been previously undetected. We find that the downdip extent of the seismogenic zone as defined by interplate seismicity agrees with the 20\% locking contour of the Schmalzle et al. (2014, https://doi.org/10.1002/2013GC005172) geodetic model and extends deeper than predicted by previous thermal models. We cannot determine the updip extent of the seismogenic zone; this may be due to a lack of templates for detection in the updip source area, stress shadows updip of asperity loading, and/or strong locking to the trench. We present a map of possible asperities determined by the small earthquakes in this study. Our asperity locations and extents show some, but not complete, agreement with the asperities modeled from the 1700 M9 rupture and geodetic locking models, and good agreement with the paleo-rupture extents determined from offshore turbidites and forearc basin-based asperity estimates. This highlights the need of continued offshore observations over time, and to elucidate fine-scale variation in locking.},
	issn = {2169-9356},
	doi = {10.1029/2023JB026607},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023JB026607},
	author = {Morton, Emily A. and Bilek, Susan L. and Rowe, Charlotte A.}
}
@article {canales_casie21-obs_2023,
	title = {CASIE21-OBS: An Open-Access, OBS Controlled-Source Seismic Data Set for Investigating the Structure and Properties of the Cascadia Accretionary Wedge and the Downgoing Explorer-Juan de Fuca-Gorda Plate System},
	journal = {Seismological Research Letters},
	volume = {94},
	year = {2023},
	note = {Publisher: Seismological Society of America (SSA)},
	month = {07/2023},
	pages = {2093{\textendash}2109},
	abstract = {Geological processes at subduction zones and their associated geohazards (e.g., megathrust earthquakes, submarine landslides, tsunamis, and arc volcanism) are, to a large extent, controlled by the structure, physical properties and fluid content of the subducting plate, the accreted sediments, and the overriding plate. In these settings, modern seismic modeling and imaging techniques based on controlled-source, multicomponent ocean-bottom seismometer (OBS) data are some of the best tools available for determining the subseafloor elastic properties, which can be linked to the aforementioned properties. Here, we present CASIE21-OBS, a controlled-source marine wide-angle OBS data set recently collected across the Cascadia convergent margin as part of the larger CAscadia Seismic Imaging Experiment 2021 (CASIE21). The main component of CASIE21 is a long-offset multichannel seismic (MCS) survey of the Cascadia margin conducted in June{\textendash}July 2021 onboard R/V M.G. Langseth (cruise MGL2104) aiming to characterize the incoming plate, the plate interface geometry and properties, and the overlying sediment stratigraphy and physical properties. CASIE21-OBS was conducted during R/V M.G. Langseth cruise MGL2103 (May 2021) and R/V Oceanus cruise OC2106A (June{\textendash}July 2021). It consisted of 63 short-period four-component OBSs deployed at a total 120 stations along 10 across-trench profiles extending from \~{}50 km seaward of the deformation front to the continental shelf, and from offshore northern Vancouver Island to offshore southern Oregon. The OBSs recorded the airgun signals of the CASIE21-MCS survey as well as natural seismicity occurring during the deployment period (24 May 2021 19:00 UTC{\textendash}9 July 2021 09:00 UTC). The OBS data are archived and available at the Incorporated Research Institutions for Seismology Data Management Center under network code YR_2021 for continuous time series (miniSEED) and identifier 21-008 for assembled data set (SEG-Y).},
	keywords = {3706 Geophysics},
	issn = {0895-0695},
	doi = {10.1785/0220230010},
	author = {Canales, Juan Pablo and Miller, Nathaniel C. and Baldwin, Wayne and Carbotte, Suzanne M. and Han, Shuoshuo and Boston, Brian and Jian, Hanchao and Collins, John and Lizarralde, Dan}
}
@article {mark_constraints_2023,
	title = {Constraints on Bend-Faulting and Mantle Hydration at the Marianas Trench From Seismic Anisotropy},
	journal = {Geophysical Research Letters},
	volume = {50},
	number = {10},
	year = {2023},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2023GL103331},
	month = {05/2023},
	pages = {e2023GL103331},
	abstract = {Subduction zones are a key link between the surface water cycle and the solid Earth, as the incoming plate carries pore water and hydrous minerals into the subsurface. However, water fluxes from surface to subsurface reservoirs over geologic time are highly uncertain because the volume of water carried in hydrous minerals in the slab mantle is poorly constrained. Estimates of slab mantle hydration based on seismic tomography assume bulk serpentinization, representing an upper bound on water volume. We measure azimuthal seismic anisotropy near the Marianas Trench, use spatial variations in anisotropy to constrain the extent and geometry of bend-related faulting, and place a lower bound on slab mantle water content for the case where serpentinization is confined within fault zones. The seismic observations can be explained by a minimum of \~{}0.85 wt\% water in the slab mantle, compared to the upper bound of \~{}2 wt\% obtained from tomography.},
	keywords = {anisotropy, Marianas Trench, serpentinization, solid-Earth water cycle, subduction},
	issn = {1944-8007},
	doi = {10.1029/2023GL103331},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023GL103331},
	author = {Mark, Hannah F. and Lizarralde, Daniel and Wiens, Douglas A.}
}
@article {boyce_new_2023,
	title = {A new P-wave Tomographic Model (CAP22) for North America: Implications for the Subduction and Cratonic Metasomatic Modification History of Western Canada and Alaska},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {128},
	number = {3},
	year = {2023},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2022JB025745},
	pages = {e2022JB025745},
	abstract = {Our understanding of the present-day state and evolution of the Canadian and Alaskan mantle is hindered by a lack of absolute P-wavespeed constraints that provide complementary sensitivity to composition in conjunction with existing S-wavespeed models. Consequently, cratonic modification, orogenic history of western North America and complexities within the Alaskan Proto-Pacific subduction system remain enigmatic. One challenge concerns the difficulties in extracting absolute arrival-time measurements from often-noisy data recorded by temporary seismograph networks required to fill gaps in continental and global databases. Using the Absolute Arrival-time Recovery Method (AARM), we extract > 180,000 new absolute arrival-time residuals from seismograph stations across Canada and Alaska and combine these data with USArray and global arrival-time data from the contiguous US and Alaska. We develop a new absolute P-wavespeed tomographic model, CAP22, spanning North America that significantly improves resolution in Canada and Alaska over previous models. Slow wavespeeds below the Canadian Cordillera sharply abut fast wavespeeds of the continental interior at the Rocky Mountain Trench in southwest Canada. Slow wavespeeds below the Mackenzie Mountains continue farther inland in northwest Canada, indicating Proterozoic-Archean metasomatism of the Slave craton. Inherited tectonic lineaments colocated with this north-south wavespeed boundary suggest that both the crust and mantle may control Cordilleran orogenic processes. In Alaska, fast upper mantle wavespeeds below the Wrangell Volcanic Field favor a conventional subduction related mechanism for volcanism. Finally, seismic evidence for the subducted Kula and Yukon slabs indicate tectonic reconstructions of western North America may require revision.},
	keywords = {Alaskan Subduction Zone, body wave tomography, Cordilleran Orogenesis, North America, Slave Craton},
	issn = {2169-9356},
	doi = {10.1029/2022JB025745},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022JB025745},
	author = {Boyce, A. and Liddell, M. V. and Pugh, S. and Brown, J. and McMurchie, E. and Parsons, A. and Est{\`e}ve, C. and Burdick, S. and Darbyshire, F. A. and Cottaar, S. and Bastow, I. D. and Schaeffer, A. J. and Audet, P. and Schutt, D. L. and Aster, R. C.}
}
@article {macgregor_seismic_2023,
	title = {A Seismic Tomography, Gravity, and Flexure Study of the Crust and Upper Mantle Structure of the Hawaiian Ridge: 1},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {128},
	number = {12},
	year = {2023},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2023JB027218},
	month = {11/2023},
	pages = {e2023JB027218},
	abstract = {The Hawaiian Ridge has long been a focus site for studying lithospheric flexure due to intraplate volcano loading, but crucial load and flexure details remain unclear. We address this problem using wide-angle seismic refraction and reflection data acquired along a \~{}535-km-long profile that intersects the ridge between the islands of Maui and Hawai{\textquoteright}i and crosses 80{\textendash}95 Myr-old lithosphere. A tomographic image constructed using travel time data of several seismic phases reveals broad flexure of Pacific oceanic crust extending up to \~{}200{\textendash}250 km either side of the Hawaiian Ridge, and vertically up to \~{}6{\textendash}7 km. The P-wave velocity structure, verified by gravity modeling, reveals that the west flank of Hawaii is comprised of extrusive lavas overlain by volcanoclastic sediments and a carbonate platform. In contrast, the H{\={a}}na Ridge, southeast of Maui, contains a high-velocity core consistent with mafic or ultramafic intrusive rocks. Magmatic underplating along the seismic line is not evident. Reflectors at the top and bottom of the pre-existing oceanic crust suggest a \~{}4.5{\textendash}6 km crustal thickness. Simple three-dimensional flexure modeling with an elastic plate thickness, Te, of 26.7 km shows that the depths to the reflectors beneath the western flank of Hawai{\textquoteright}i can be explained by volcano loading in which Maui and the older islands in the ridge contribute \~{}43\% to the flexure and the island of Hawai{\textquoteright}i \~{}51\%. Previous studies, however, revealed a higher Te beneath the eastern flank of Hawai{\textquoteright}i suggesting that isostatic compensation may not yet be complete at the youngest end of the ridge.},
	keywords = {Hawaiian ridge, lithospheric flexure, marine gravity, plate loading, seismic tomography, volcano structure},
	issn = {2169-9356},
	doi = {10.1029/2023JB027218},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023JB027218},
	author = {MacGregor, B. G. and Dunn, R. A. and Watts, A. B. and Xu, C. and Shillington, D. J.}
}
@article {262,
	title = {Slab to back-arc to arc: Fluid and melt pathways through the mantle wedge beneath the Lesser Antilles},
	journal = {Science Advances},
	volume = {9},
	year = {2023},
	month = {02/2023},
	pages = {eadd2143},
	abstract = {Volatiles expelled from subducted plates promote melting of the overlying warm mantle, feeding arc volcanism. However, debates continue over the factors controlling melt generation and transport, and how these determine the placement of volcanoes. To broaden our synoptic view of these fundamental mantle wedge processes, we image seismic attenuation beneath the Lesser Antilles arc, an end-member system that slowly subducts old, tectonized lithosphere. Punctuated anomalies with high ratios of bulk-to-shear attenuation (Qκ-1/Qμ-1 > 0.6) and VP/VS (>1.83) lie 40 km above the slab, representing expelled fluids that are retained in a cold boundary layer, transporting fluids toward the back-arc. The strongest attenuation (1000/QS ~ 20), characterizing melt in warm mantle, lies beneath the back-arc, revealing how back-arc mantle feeds arc volcanoes. Melt ponds under the upper plate and percolates toward the arc along structures from earlier back-arc spreading, demonstrating how slab dehydration, upper-plate properties, past tectonics, and resulting melt pathways collectively condition volcanism.},
	keywords = {3706 Geophysics},
	issn = {2375-2548},
	doi = {10.1126/sciadv.add2143},
	url = {https://www.science.org/doi/10.1126/sciadv.add2143},
	author = {Hicks, SP and Bie, L and Rychert, CA and Harmon, N and Goes, S and Rietbrock, A and Wei, SS and Collier, JS and Henstock, TJ and Lynch, L and Prytulak, J and Macpherson, CG and Schlaphorst, D and Wilkinson, JJ and Blundy, JD and Cooper, GF and Davy, RG and Kendall, J-M and VOILA WORKING GROUP}
}
@article {janiszewski_broad-band_2023,
	title = {Broad-band ocean bottom seismometer noise properties},
	journal = {Geophysical Journal International},
	volume = {233},
	number = {1},
	year = {2022},
	month = {11/2022},
	pages = {297{\textendash}315},
	abstract = {We present a new compilation and analysis of broad-band ocean bottom seismometer noise properties from 15 yr of seismic deployments. We compile a comprehensive data set of representative four-component (seismometer and pressure gauge) noise spectra and cross-spectral properties (coherence, phase and admittance) for 551 unique stations spanning 18 U.S.-led experiments. This is matched with a comprehensive compilation of metadata parameters related to instrumentation and environmental properties for each station. We systematically investigate the similarity of noise spectra by grouping them according to these metadata parameters to determine which factors are the most important in determining noise characteristics. We find evidence for improvements in similarity of noise properties when grouped across parameters, with groupings by seismometer type and deployment water depth yielding the most significant and interpretable results. Instrument design, that is the entire deployed package, also plays an important role, although it strongly covaries with seismometer and water depth. We assess the presence of traditional sources of tilt, compliance, and microseismic noise to characterize their relative role across a variety of commonly used seismic frequency bands. We find that the presence of tilt noise is primarily dependent on the type of seismometer used (covariant with a particular subset of instrument design), that compliance noise follows anticipated relationships with water depth, and that shallow, oceanic shelf environments have systematically different microseism noise properties (which are, in turn, different from instruments deployed in shallow lake environments). These observations have important implications for the viability of commonly used seismic analysis techniques. Finally, we compare spectra and coherences before and after vertical channel tilt and compliance noise removal to evaluate the efficacy and limitations of these now standard processing techniques. These findings may assist in future experiment planning and instrument development, and our newly compiled noise data set serves as a building block for more targeted future investigations by the marine seismology community.},
	issn = {0956-540X},
	doi = {10.1093/gji/ggac450},
	url = {https://doi.org/10.1093/gji/ggac450},
	author = {Janiszewski, Helen A and Eilon, Z and Russell, J B and Brunsvik, B and Gaherty, J B and Mosher, S G and Hawley, W B and Coats, S}
}
@article {iwasaki_continuous_2022,
	title = {Continuous Tremor Activity With Stable Polarization Direction Following the 2014 Large Slow Slip Event in the Hikurangi Subduction Margin Offshore New Zealand},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {127},
	number = {2},
	year = {2022},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2021JB022161},
	month = {11/2021},
	pages = {e2021JB022161},
	abstract = {Many types of slow earthquakes have been discovered at subduction zones around the world. However, the physical process of these slow earthquakes is not well understood. To monitor offshore slow earthquakes, a marine seismic and geodetic experiment was conducted at the Hikurangi subduction margin from May 2014 to June 2015. During this experiment, a large slow slip event (Mw 6.8) occurred directly beneath the ocean bottom seismometer (OBS) network. In this study, S-wave splitting and polarization analysis methods, which have been previously used on onshore data to investigate tremor and anisotropy, are applied to continuous OBS waveform data to identify tremors that are too small to detect by the envelope cross correlation method. Continuous tremor activity with stable polarization directions is detected at the end of the 2014 slow slip event and continued for about 2 weeks. The tremors are generated around a southwest bend in the slow slip contours and at the landward edge of a subducted seamount. Our findings corroborate a previous interpretation, based on burst-type repeating earthquakes and intermittent tremor, that localized slow slip and tremor around the seamount was triggered by fluid migration following the large plate boundary slow slip event and indicate tremor occurred continuously rather than as isolated and sporadic individual events.},
	keywords = {New Zealand, polarization, S-wave splitting, Seamount, slow slip, tremor},
	issn = {2169-9356},
	doi = {10.1029/2021JB022161},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021JB022161},
	author = {Iwasaki, Yuriko and Mochizuki, Kimihiro and Ishise, Motoko and Todd, Erin K. and Schwartz, Susan Y. and Zal, Hubert and Savage, Martha K. and Henrys, Stuart and Sheehan, Anne F. and Ito, Yoshihiro and Wallace, Laura M. and Webb, Spahr C. and Yamada, Tomoaki and Shinohara, Masanao}
}
@article {wei_improved_2022,
	title = {An Improved Earthquake Catalog During the 2018 K{\i}̄lauea Eruption From Combined Onshore and Offshore Seismic Arrays},
	journal = {Earth and Space Science},
	volume = {9},
	number = {6},
	year = {2022},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2021EA001979},
	month = {06/2022},
	pages = {e2021EA001979},
	abstract = {The Island of Hawai{\textquoteright}i was formed by repeated eruptions of basalts at an oceanic hotspot. K{\i}̄lauea, the youngest among the subaerial volcanoes of the island, erupted intensely in 2018. The eruption provided an opportunity to look into the mechanisms that operate at the volcano and associated earthquake activities, as it was recorded simultaneously, for the first time, by onshore and offshore seismometers. We used most of the publicly available seismic data during the eruption period, including temporary arrays, to build a more complete earthquake catalog during the eruption than that provided by the Hawaiian Volcano Observatory. We used a short-time-average/long-time-average method to identify potential earthquakes. The detections were associated with events and automatically picked with P-wave and S-wave arrivals, which were used to locate the events in a three-dimensional velocity model. After re-examining these earthquake events, their coda/duration magnitudes were determined. The resulting half-year catalog contains 375,736 events with one of the highest daily earthquake numbers ever reported (6,128 on 21 June 2018). A great number of events were recorded during the caldera collapses, from its beginning until its rapid ending. The catalog also contains abundant events near the Pu{\textquoteright}u{\textquoteleft}o{\textquoteleft}o vent and in the lower East Rift Zone, where an increase of seismicity in mid-July and August indicated a step-up in magma intrusion after the eruption.},
	keywords = {eruption, K{\i}̄lauea, offshore, onshore, seismicity},
	issn = {2333-5084},
	doi = {10.1029/2021EA001979},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021EA001979},
	author = {Wei, XiaoZhuo and Shen, Yang and Caplan-Auerbach, Jacqueline and Morgan, Julia K.}
}
@article {chrapkiewicz_magma_2022,
	title = {Magma Chamber Detected Beneath an Arc Volcano With Full-Waveform Inversion of Active-Source Seismic Data},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {23},
	number = {11},
	year = {2022},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2022GC010475},
	month = {10/2022},
	pages = {e2022GC010475},
	abstract = {Arc volcanoes are underlain by complex systems of molten-rock reservoirs ranging from melt-poor mush zones to melt-rich magma chambers. Petrological and satellite data indicate that eruptible magma chambers form in the topmost few kilometres of the crust. However, very few chambers have ever been definitively located, suggesting that most are too short-lived or too small to be imaged, which has direct implications for hazard assessment and modeling of magma differentiation. Here we use a high-resolution technology based on inverting full seismic waveforms to image a small, high-melt-fraction magma chamber that was not detected with standard seismic tomography. The melt reservoir extends from \~{}2 to at least 4 km below sea level (b.s.l.) at Kolumbo{\textemdash}a submarine volcano near Santorini, Greece. The chamber coincides with the termination point of the recent earthquake swarms and may be a missing link between a deeper melt reservoir and the high-temperature hydrothermal system venting at the crater floor. The chamber poses a serious hazard as it could produce a highly explosive, tsunamigenic eruption in the near future. Our results suggest that similar reservoirs (relatively small but high-melt-fraction) may have gone undetected at other active volcanoes, challenging the existing eruption forecasts and reactive-flow models of magma differentiation.},
	keywords = {full-waveform inversion, Kolumbo volcano, magma chamber, magmatic system, Santorini volcanic field, volcano tomography},
	issn = {1525-2027},
	doi = {10.1029/2022GC010475},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022GC010475},
	author = {Chrapkiewicz, K. and Paulatto, M. and Heath, B. A. and Hooft, E. E. E. and Nomikou, P. and Papazachos, C. B. and Schmid, F. and Toomey, D. R. and Warner, M. R. and Morgan, J. V.}
}
@article {le_seismic_2022,
	title = {Seismic Constraints on Crustal and Uppermost Mantle Structure Beneath the Hawaiian Swell: Implications for Plume-Lithosphere Interactions},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {127},
	number = {11},
	year = {2022},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2021JB023822},
	month = {10/2022},
	pages = {e2021JB023822},
	abstract = {We infer the lithospheric structure beneath the Hawaiian Swell based on a joint inversion of ambient noise and teleseismic Rayleigh waves collected during the PLUME experiment. These combined datasets let us use Rayleigh waves with a period range of 8{\textendash}50 s that provides imaging resolution for the shallow lithosphere and constrains interactions between the upwelling plume and migrating plate. We find an elongated low-velocity anomaly beneath the lithosphere along the island chain that connects to the plume conduit, consistent with the melting region associated with a restite hotspot swell root that has mechanically eroded the base of its overlying lithosphere. It could also be consistent with a plume refracted by the overriding plate motion if the plume could manage to deeply erode the lithospheric base, as only a more viscous restite root is seen to do in thermomechanical experiments. There is also a low-velocity body beneath the North Arch that coincides with the location of recent off-chain volcanic fields discovered there. Its location relative to the Molokai Fracture Zone (MFZ) supports the concept that swell-root material has preferentially spread beneath the younger side of the MFZ. We also find a clear low-velocity anomaly associated with the uppermost \~{}50 km of the fracture zone lithosphere. The relatively well-resolved shallow lithospheric structure determined here allows us to estimate the volumes of underplating and the total flux of the rising plume material that is added beneath the Hawaiian lithosphere, which we constrain to be in the range of 0.5{\textendash}0.6 km3/yr.},
	keywords = {ambient noise, Hawaiian swell, Rayleigh waves, tomography, underplating},
	issn = {2169-9356},
	doi = {10.1029/2021JB023822},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021JB023822},
	author = {Le, Ba Manh and Yang, Ting and Morgan, Jason P.}
}
@article {russell_seismological_2022,
	title = {Seismological Evidence for Girdled Olivine Lattice-Preferred Orientation in Oceanic Lithosphere and Implications for Mantle Deformation Processes During Seafloor Spreading},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {23},
	number = {10},
	year = {2022},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2022GC010542},
	pages = {e2022GC010542},
	abstract = {Seismic anisotropy produced by aligned olivine in oceanic lithosphere offers a window into mid-ocean ridge (MOR) dynamics. Yet, interpreting anisotropy in the context of grain-scale deformation processes and strain observed in laboratory experiments and natural olivine samples has proven challenging due to incomplete seismological constraints and length scale differences spanning orders of magnitude. To bridge this observational gap, we estimate an in situ elastic tensor for oceanic lithosphere using co-located compressional- and shear-wavespeed anisotropy observations at the NoMelt experiment located on \~{}70 Ma seafloor. The elastic model for the upper 7 km of the mantle, NoMelt_SPani7, is characterized by a fast azimuth parallel to the fossil-spreading direction, consistent with corner-flow deformation fabric. We compare this model with a database of 123 petrofabrics from the literature to infer olivine crystallographic orientations and shear strain accumulated within the lithosphere. Direct comparison to olivine deformation experiments indicates strain accumulation of 250\%{\textendash}400\% in the shallow mantle. We find evidence for D-type olivine lattice-preferred orientation (LPO) with fast [100] parallel to the shear direction and girdled [010] and [001] crystallographic axes perpendicular to shear. D-type LPO implies similar amounts of slip on the (010)[100] and (001)[100] easy slip systems during MOR spreading; we hypothesize that grain-boundary sliding during dislocation creep relaxes strain compatibility, allowing D-type LPO to develop in the shallow lithosphere. Deformation dominated by dislocation-accommodated grain-boundary sliding (disGBS) has implications for in situ stress and grain size during MOR spreading and implies grain-size dependent deformation, in contrast to pure dislocation creep.},
	keywords = {grain-boundary sliding, mid-ocean ridge, oceanic lithosphere, seafloor spreading, seismic anisotropy, surface waves},
	issn = {1525-2027},
	doi = {10.1029/2022GC010542},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022GC010542},
	author = {Russell, J. B. and Gaherty, J. B. and Mark, H. F. and Hirth, G. and Hansen, L. N. and Lizarralde, D. and Collins, J. A. and Evans, R. L.}
}
@article {wang_temporal_2022,
	title = {Temporal velocity variations in the northern Hikurangi margin and the relation to slow slip},
	journal = {Earth and Planetary Science Letters},
	volume = {584},
	year = {2022},
	month = {04/2022},
	pages = {117443},
	abstract = {Slow slip events (SSE) have been studied in increasing detail over the last 20 years, improving our understanding of subduction zone processes. Although the relationship between SSEs and the physical properties of their surrounding materials is still not well-understood, the northern Hikurangi margin in New Zealand is the site of relatively shallow (<10 km deep), frequent SSEs, providing excellent opportunities for near-field investigations. From September to October 2014, an SSE occurred with more than 250 mm slip, and was recorded successfully by the Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip (HOBITSS) deployment. This study applies scattered wave interferometry to ambient noise data acquired by nine HOBITSS ocean bottom seismometers (OBS) to study the seismic velocity variations related to the SSE. Single station cross-component correlations are computed within a period band that focuses on the upper plate in our study region. The average velocity variations display a decrease on the order of 0.05\% during the SSE, followed by an increase of similar magnitude afterwards. We suggest two possibilities. The first possibility, which has been suggested by other seismological observations, is that the SSE causes a low-permeability seal on the plate boundary to break. The break allows fluid to migrate into the upper plate, causing a seismic velocity decrease during the SSE because of increased pore fluid volume in the upper plate. Under this model, after the SSE, the fluids in the upper plate diffuse gradually and the velocity increases again. The second possibility is the velocity changes are related to changes in crustal strain during the slow slip cycle, whereby elastic strain accumulates prior to the SSE, causing contraction and reduction of porosity and therefore increase of velocity above the SSE source (the seismic velocity increases between SSEs). During the SSE the upper plate goes into extension as the elastic strain is released, which results in dilation and a porosity increase (seismic velocity reduction). After the SSE, stress and strain accumulate again, causing a porosity decrease and a velocity increase.},
	keywords = {ambient noise, seismic velocity variations, slow slip event, the Hikurangi subduction zone},
	issn = {0012-821X},
	doi = {10.1016/j.epsl.2022.117443},
	url = {https://www.sciencedirect.com/science/article/pii/S0012821X22000796},
	author = {Wang, Weiwei and Savage, Martha K. and Yates, Alexander and Zal, Hubert J. and Webb, Spahr and Boulton, Carolyn and Warren-Smith, Emily and Madley, Megan and Stern, Tim and Fry, Bill and Mochizuki, Kimihiro and Wallace, Laura}
}
@article {kleckner_automated_2021,
	title = {Automated Detection of Clipping in Broadband Earthquake Records},
	journal = {Seismological Research Letters},
	volume = {93},
	number = {2A},
	year = {2021},
	month = {dec},
	pages = {880{\textendash}896},
	abstract = {Because the amount of available ground-motion data has increased over the last decades, the need for automated processing algorithms has also increased. One difficulty with automated processing is to screen clipped records. Clipping occurs when the ground-motion amplitude exceeds the dynamic range of the linear response of the instrument. Clipped records in which the amplitude exceeds the dynamic range are relatively easy to identify visually yet challenging for automated algorithms. In this article, we seek to identify a reliable and fully automated clipping detection algorithm tailored to near-real-time earthquake response needs. We consider multiple alternative algorithms, including (1)~an algorithm based on the percentage difference in adjacent data points, (2)~the standard deviation of the data within a moving window, (3)~the shape of the histogram of the recorded amplitudes, (4)~the second derivative of the data, and (5)~the amplitude of the data. To quantitatively compare these algorithms, we construct development and holdout datasets from earthquakes across a range of geographic regions, tectonic environments, and instrument types. We manually classify each record for the presence of clipping and use the classified records. We then develop an artificial neural network model that combines all the individual algorithms. Testing on the holdout dataset, the standard deviation and histogram approaches are the most accurate individual algorithms, with an overall accuracy of about 93\%. The combined artificial neural network method yields an overall accuracy of 95\%, and the choice of classification threshold can balance precision and recall.},
	issn = {0895-0695},
	doi = {10.1785/0220210028},
	url = {https://doi.org/10.1785/0220210028},
	author = {Kleckner, James K. and Withers, Kyle B. and Thompson, Eric M. and Rekoske, John M. and Wolin, Emily and Moschetti, Morgan P.}
}
@article {mark_constraints_2021,
	title = {Constraints on the Depth, Thickness, and Strength of the G Discontinuity in the Central Pacific From S Receiver Functions},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {126},
	number = {4},
	year = {2021},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2019JB019256},
	month = {03/2021},
	pages = {e2019JB019256},
	abstract = {The relative motion of the lithosphere with respect to the asthenosphere implies the existence of a boundary zone that accommodates shear between the rigid plates and flowing mantle. This shear zone is typically referred to as the lithosphere-asthenosphere boundary (LAB). The width of this zone and the mechanisms accommodating shear across it have important implications for coupling between mantle convection and surface plate motion. Seismic observations have provided evidence for several physical mechanisms that might help enable relative plate motion, but how these mechanisms each contribute to the overall accommodation of shear remains unclear. Here we present receiver function constraints on the discontinuity structure of the oceanic upper mantle at the NoMelt site in the central Pacific, where local constraints on shear velocity, anisotropy, conductivity, and attenuation down to \~{}300 km depth provide a comprehensive picture of upper mantle structure. We image a seismic discontinuity with a Vsv decrease of 4.5\% or more over a 0{\textendash}20 km thick gradient layer centered at a depth of \~{}65 km. We associate this feature with the Gutenberg discontinuity (G), and interpret our observation of G as resulting from strain localization across a dehydration boundary based on the good agreement between the discontinuity depth and that of the dry solidus. Transitions in Vsv, azimuthal anisotropy, conductivity, and attenuation observed at roughly similar depths suggest that the G discontinuity represents a region of localized strain within a broader zone accommodating shear between the lithosphere and asthenosphere.},
	issn = {2169-9356},
	doi = {10.1029/2019JB019256},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JB019256},
	author = {Mark, H. F. and Collins, J. A. and Lizarralde, D. and Hirth, G. and Gaherty, J. B. and Evans, R. L. and Behn, M. D.}
}
@article {gong_constraints_2021,
	title = {Constraints on the Geometry of the Subducted Gorda Plate From Converted Phases Generated by Local Earthquakes},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {126},
	number = {2},
	year = {2021},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2020JB019962},
	month = {01/2021},
	pages = {e2020JB019962},
	abstract = {The largest slip in great megathrust earthquakes often occurs in the 10{\textendash}30 km depth range, yet seismic imaging of the material properties in this region has proven difficult. We utilize a dense onshore-offshore passive seismic dataset from the southernmost Cascadia subduction zone where seismicity in the mantle of the subducted Gorda Plate produces S-to-P and P-to-S conversions generated within a few km of the plate interface. These conversions typically occur in the 10{\textendash}20 km depth range at either the top or bottom of a \~{}5 km thick layer with a high Vp/Vs that we infer to be primarily the subducted crust. We use their arrival times and amplitudes to infer the location of the top and bottom of the subducted crust as well as the velocity contrasts across these discontinuities. Comparing with both the Slab1.0 and the updated Slab2 interface models, the Slab2 model is generally consistent with the converted phases, while the Slab1.0 model is 1{\textendash}2 km deeper in the 2{\textendash}20 km depth range and \~{}6{\textendash}8 km too deep in the 10{\textendash}20 km depth range between 40.25{\textdegree}N and 40.4{\textdegree}N. Comparing the amplitudes of the converted phases to synthetics for simplified velocity structures, the amplitude of the converted phases requires models containing a \~{}5 km thick zone with at least a \~{}10\%{\textendash}20\% reduction in S wave velocity. Thus, the plate boundary is likely contained within or at the top of this low velocity zone, which potentially indicates a significant porosity and fluid content within the seismogenic zone.},
	keywords = {converted phases, seismic imaging, subduction zone plate boundary},
	issn = {2169-9356},
	doi = {10.1029/2020JB019962},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020JB019962},
	author = {Gong, Jianhua and McGuire, Jeffrey J.}
}
@article {eilon_pacific_2021,
	title = {The Pacific OBS Research into Convecting Asthenosphere (ORCA) Experiment},
	journal = {Seismological Research Letters},
	volume = {93},
	number = {1},
	year = {2021},
	month = {01/2022},
	pages = {477{\textendash}493},
	abstract = {The Pacific ocean-bottom seismometer (OBS) Research into Convecting Asthenosphere (ORCA) experiment deployed two 30-station seismic arrays between 2018 and 2020{\textemdash}a US contribution to the international PacificArray project. The {\textquotedblleft}Young ORCA{\textquotedblright} array deployed on \~{}40~Ma central Pacific seafloor had a \~{}68\% data recovery rate, whereas the {\textquotedblleft}Old ORCA{\textquotedblright} array deployed on \~{}120~Ma southwest Pacific seafloor had a \~{}80\% recovery rate. We detail here the seismic data quality, spectral characteristics, and engineering challenges of this experiment. We provide information to assist users of this dataset, including OBS orientations and tables of daily data quality for all channels. Preliminary analysis illustrates the utility of these data for surface- and body-wave seismic imaging.},
	issn = {0895-0695},
	doi = {10.1785/0220210173},
	url = {https://doi.org/10.1785/0220210173},
	author = {Eilon, Zachary C. and Gaherty, James B. and Zhang, Lun and Russell, Joshua and McPeak, Sean and Phillips, Joseph and Forsyth, Donald W. and Ekstr{\"o}m, G{\"o}ran}
}
@article {heath_relationship_2021,
	title = {Relationship Between Active Faulting/Fracturing and Magmatism Around Santorini: Seismic Anisotropy From an Active Source Tomography Experiment},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {126},
	number = {8},
	year = {2021},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2021JB021898},
	month = {07/2021},
	pages = {e2021JB021898},
	abstract = {In extending volcanic arcs such as the Aegean, tectonic processes exert a significant control on magmatism. Spanning scales from 1 to 10s of km, volcanic vents, edifices, and eruptive centers follow the orientation of, and are located near, fault zones. Whether this tectonic control on magmatism results from individual faults/fractures weakening the crust or because regional stresses control magma input into the crust is debated. Here we investigate the scales of tectonic and magmatic interactions, specifically focusing on the role of local-scale (<10 km) faults/fractures in controlling magmatism. We infer local-scale fault/fracture orientations from anisotropic active-source P-wave travel-time tomography to investigate tectonic and magmatic interactions in the upper crust of Santorini Volcano, Greece, and the actively deforming region to the east. We use the anisotropy magnitude and seismic velocity reduction to model the relative distribution of both consistently oriented and randomly oriented faults/fractures. Our results show that oriented faulting/fracturing resulting from regional-scale (>10 km) tectonic stresses is distributed broadly across the region at 2{\textendash}3 km depth, approximately paralleling volcanic/magmatic features. On a local-scale, magmatism is neither localized in areas of higher oriented fault/fracture density, nor is it accommodating enough extensional strain to inhibit oriented faulting/fracturing of host rock. The alignment of magmatic features shows strong tectonic control despite the lack of correlation with local oriented fault/fracture density. These results suggest that magmatic processes are strongly influenced by regional-scale, not local-scale, tectonic processes. We infer regional processes have a greater impact on magmatism than local features due to their greater effect at depth.},
	keywords = {anisotropy, faulting, magmatism, seismology, tectonism, tectono-magmatism},
	issn = {2169-9356},
	doi = {10.1029/2021JB021898},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021JB021898},
	author = {Heath, B. A. and Hooft, E. E. E. and Toomey, D. R. and Paulatto, M. and Papazachos, C. B. and Nomikou, P. and Morgan, J. V.}
}
@article {barcheck_alaska_2020,
	title = {The Alaska Amphibious Community Seismic Experiment},
	journal = {Seismological Research Letters},
	volume = {91},
	number = {6},
	year = {2020},
	month = {08/2020},
	pages = {3054{\textendash}3063},
	abstract = {The Alaska Amphibious Community Seismic Experiment (AACSE) is a shoreline-crossing passive- and active-source seismic experiment that took place from May 2018 through August 2019 along an \~{}700  km long section of the Aleutian subduction zone spanning Kodiak Island and the Alaska Peninsula. The experiment featured 105 broadband seismometers; 30 were deployed onshore, and 75 were deployed offshore in Ocean Bottom Seismometer (OBS) packages. Additional strong-motion instruments were also deployed at six onshore seismic sites. Offshore OBS stretched from the outer rise across the trench to the shelf. OBSs in shallow water (\&lt;262  m depth) were deployed with a trawl-resistant shield, and deeper OBSs were unshielded. Additionally, a number of OBS-mounted strong-motion instruments, differential and absolute pressure gauges, hydrophones, and temperature and salinity sensors were deployed. OBSs were deployed on two cruises of the R/V Sikuliaq in May and July 2018 and retrieved on two cruises aboard the R/V Sikuliaq and R/V Langseth in August{\textendash}September 2019. A complementary 398-instrument nodal seismometer array was deployed on Kodiak Island for four weeks in May{\textendash}June 2019, and an active-source seismic survey on the R/V Langseth was arranged in June 2019 to shoot into the AACSE broadband network and the nodes. Additional underway data from cruises include seafloor bathymetry and sub-bottom profiles, with extra data collected near the rupture zone of the 2018 Mw~7.9 offshore-Kodiak earthquake. The AACSE network was deployed simultaneously with the EarthScope Transportable Array (TA) in Alaska, effectively densifying and extending the TA offshore in the region of the Alaska Peninsula. AACSE is a community experiment, and all data were made available publicly as soon as feasible in appropriate repositories.},
	issn = {0895-0695},
	doi = {10.1785/0220200189},
	url = {https://doi.org/10.1785/0220200189},
	author = {Barcheck, Grace and Abers, Geoffrey A. and Adams, Aubreya N. and B{\'e}cel, Anne and Collins, John and Gaherty, James B. and Haeussler, Peter J. and Li, Zongshan and Moore, Ginevra and Onyango, Evans and Roland, Emily and Sampson, Daniel E. and Schwartz, Susan Y. and Sheehan, Anne F. and Shillington, Donna J. and Shore, Patrick J. and Webb, Spahr and Wiens, Douglas A. and Worthington, Lindsay L.}
}
@article {116,
	title = {Limited mantle hydration by bending faults at the Middle America Trench},
	journal = {Journal of Geophysical Research: Solid Earth},
	year = {2020},
	type = {Journal Article},
	abstract = {Seismic anisotropy measurements show that upper mantle hydration at the Middle America Trench (MAT) is limited to serpentinization and/or water in fault zones, rather than distributed uniformly. Subduction of hydrated oceanic lithosphere recycles water back into the deep mantle, drives arc volcanism, and affects seismicity at subduction zones. Constraining the extent of upper mantle hydration is an important part of understanding many fundamental processes on Earth. Substantially reduced seismic velocities in tomography suggest that outer rise plate-bending faults provide a pathway for seawater to rehydrate the slab mantle just prior to subduction. Estimates of outer-rise hydration based on tomograms vary significantly, with some large enough to imply that, globally, subduction has consumed more than two oceans worth of water during the Phanerozoic. We found that, while the mean upper mantle wavespeed is reduced at the MAT outer rise, the amplitude and orientation of inherited anisotropy are preserved at depths >1 km below the Moho. At shallower depths, relict anisotropy is replaced by slowing in the fault-normal direction. These observations are incompatible with pervasive hydration but consistent with models of wave propagation through serpentinized fault zones that thin to <100-m in width at depths >1 km below Moho. Confining hydration to fault zones reduces water storage estimates for the MAT upper mantle from \~{}3.5 wt\% to <0.9 wt\% H20. Since the intermediate thermal structure in the \~{}24 Myr-old MAT slab favors serpentinization, limited hydration suggests that fault mechanics are the limiting factor, not temperatures. Subducting mantle may be similarly dry globally. This article is protected by copyright. All rights reserved. Upper mantle anisotropy indicates that hydration by fluid flow along bending faults is limited to fault zones that thin with depthConfining hydration to fault zones reduces estimates of water storage by an order of magnitudeA dry, intermediate-age slab mantle suggests that hydration may be globally limited by fault dynamics, rather than temperature Upper mantle anisotropy indicates that hydration by fluid flow along bending faults is limited to fault zones that thin with depth Confining hydration to fault zones reduces estimates of water storage by an order of magnitude A dry, intermediate-age slab mantle suggests that hydration may be globally limited by fault dynamics, rather than temperature.},
	doi = {10.1029/2020jb020982},
	url = {https://app.dimensions.ai/details/publication/pub.1133689698},
	author = {Miller, Nathaniel C. and Lizarralde, Daniel and Collins, John A. and Holbrook, W. Steven and Van Avendonk, H.}
}
@article {miller_limited_2020,
	title = {Limited mantle hydration by bending faults at the Middle America Trench},
	journal = {Journal of Geophysical Research: Solid Earth},
	year = {2020},
	note = {Type: Journal Article},
	month = {12/2020},
	abstract = {Seismic anisotropy measurements show that upper mantle hydration at the Middle America Trench (MAT) is limited to serpentinization and/or water in fault zones, rather than distributed uniformly. Subduction of hydrated oceanic lithosphere recycles water back into the deep mantle, drives arc volcanism, and affects seismicity at subduction zones. Constraining the extent of upper mantle hydration is an important part of understanding many fundamental processes on Earth. Substantially reduced seismic velocities in tomography suggest that outer rise plate-bending faults provide a pathway for seawater to rehydrate the slab mantle just prior to subduction. Estimates of outer-rise hydration based on tomograms vary significantly, with some large enough to imply that, globally, subduction has consumed more than two oceans worth of water during the Phanerozoic. We found that, while the mean upper mantle wavespeed is reduced at the MAT outer rise, the amplitude and orientation of inherited anisotropy are preserved at depths >1 km below the Moho. At shallower depths, relict anisotropy is replaced by slowing in the fault-normal direction. These observations are incompatible with pervasive hydration but consistent with models of wave propagation through serpentinized fault zones that thin to <100-m in width at depths >1 km below Moho. Confining hydration to fault zones reduces water storage estimates for the MAT upper mantle from \~{}3.5 wt\% to <0.9 wt\% H20. Since the intermediate thermal structure in the \~{}24 Myr-old MAT slab favors serpentinization, limited hydration suggests that fault mechanics are the limiting factor, not temperatures. Subducting mantle may be similarly dry globally. This article is protected by copyright. All rights reserved. Upper mantle anisotropy indicates that hydration by fluid flow along bending faults is limited to fault zones that thin with depthConfining hydration to fault zones reduces estimates of water storage by an order of magnitudeA dry, intermediate-age slab mantle suggests that hydration may be globally limited by fault dynamics, rather than temperature Upper mantle anisotropy indicates that hydration by fluid flow along bending faults is limited to fault zones that thin with depth Confining hydration to fault zones reduces estimates of water storage by an order of magnitude A dry, intermediate-age slab mantle suggests that hydration may be globally limited by fault dynamics, rather than temperature.},
	keywords = {outer-rise hydration, upper mantle anisotropy, upper mantle hydration},
	doi = {10.1029/2020jb020982},
	url = {https://app.dimensions.ai/details/publication/pub.1133689698},
	author = {Miller, Nathaniel C. and Lizarralde, Daniel and Collins, John A. and Holbrook, W. Steven and Van Avendonk, H.}
}
@article {McVey2020,
	title = {Magma accumulation beneath Santorini volcano, Greece, from P-wave tomography},
	journal = {Geology},
	volume = {48},
	number = {3},
	year = {2020},
	month = {mar},
	pages = {231{\textendash}235},
	abstract = {Despite multidisciplinary evidence for crustal magma accumulation below Santorini volcano, Greece, the structure and melt content of the shallow magmatic system remain poorly constrained. We use three-dimensional (3-D) velocity models from tomographic inversions of active-source seismic P-wave travel times to identify a pronounced low-velocity anomaly ({\textendash}21\%) from 2.8 km to 5 km depth localized below the northern caldera basin. This anomaly is consistent with depth estimates of pre-eruptive storage and a recent inflation episode, supporting the interpretation of a shallow magma body that causes seismic attenuation and ray bending. A suite of synthetic tests shows that the geometry is well recovered while a range of melt contents (4\%{\textendash}13\% to fully molten) are allowable. A thin mush region (2\%{\textendash}7\% to 3\%{\textendash}10\% melt) extends from the main magma body toward the northeast, observed as low velocities confined by tectono-magmatic lineaments. This anomaly terminates northwest of Kolumbo; little to no melt underlies the seamount from 3 to 5 km depth. These structural constraints suggest that crustal extension and edifice loads control the geometry of magma accumulation and emphasize that the shallow crust remains conducive to melt storage shortly after a caldera-forming eruption.},
	issn = {0091-7613},
	doi = {10.1130/G47127.1},
	url = {https://pubs.geoscienceworld.org/gsa/geology/article/48/3/231/579527/Magma-accumulation-beneath-Santorini-volcano},
	author = {McVey, B.G. and Hooft, E.E.E. and Heath, B.A. and Toomey, D.R. and Paulatto, M. and Morgan, J.V. and Nomikou, P. and Papazachos, C.B.}
}
@article {wei_obs_2020,
	title = {An OBS Array to Investigate Offshore Seismicity during the 2018~Kilauea Eruption},
	journal = {Seismological Research Letters},
	volume = {92},
	number = {1},
	year = {2020},
	month = {01/2021},
	pages = {603{\textendash}612},
	abstract = {On 3 May 2018, Kilauea Volcano, one of the most active volcanoes in the world, entered a new eruptive phase because of a dike intrusion in the East Rift zone. One day later, an Mw~6.9 earthquake, which was likely trigged by the dike intrusion, occurred in the submarine south flank of Kilauea Volcano. In mid-July, an ocean-bottom seismometer (OBS) array consisting of 12 stations was deployed on the submarine south flank of Kilauea Volcano to monitor the aftershocks and lava{\textendash}water interaction near the ocean entry. Eleven OBSs were recovered in mid-September. Preliminary evaluation of the data reveals a large number of seismic and acoustic events, which provide a valuable dataset for understanding flank deformation and stability as well as lava{\textendash}water interaction. Here, we introduce this dataset and document notable instrument malfunctions along with some initial seismic and acoustic observations.},
	issn = {0895-0695},
	doi = {10.1785/0220200206},
	url = {https://doi.org/10.1785/0220200206},
	author = {Wei, XiaoZhuo and Shen, Yang and Caplan-Auerbach, Jacqueline and Morgan, Julia K.}
}
@article {parnell-turner_seismicity_2020,
	title = {Seismicity trends and detachment fault structure at 13{\textdegree}N, Mid-Atlantic Ridge},
	journal = {Geology},
	volume = {49},
	number = {3},
	year = {2020},
	month = {11/2020},
	pages = {320{\textendash}324},
	abstract = {At slow-spreading ridges, plate separation is commonly partly accommodated by slip on long-lived detachment faults, exposing upper mantle and lower crustal rocks on the seafloor. However, the mechanics of this process, the subsurface structure, and the interaction of these faults remain largely unknown. We report the results of a network of 56 ocean-bottom seismographs (OBSs), deployed in 2016 at the Mid-Atlantic Ridge near 13{\textdegree}N, that provided dense spatial coverage of two adjacent detachment faults and the intervening ridge axis. Although both detachments exhibited high levels of seismicity, they are separated by an \~{}8-km-wide aseismic zone, indicating that they are mechanically decoupled. A linear band of seismic activity, possibly indicating magmatism, crosscuts the 13{\textdegree}30'N domed detachment surface, confirming previous evidence for fault abandonment. Farther south, where the 2016 OBS network spatially overlapped with a similar survey done in 2014, significant changes in the patterns of seismicity between these surveys are observed. These changes suggest that oceanic detachments undergo previously unobserved cycles of stress accumulation and release as plate spreading is accommodated.},
	issn = {0091-7613},
	doi = {10.1130/G48420.1},
	url = {https://doi.org/10.1130/G48420.1},
	author = {Parnell-Turner, R. and Sohn, R.A. and Peirce, C. and Reston, T.J. and MacLeod, C.J. and Searle, R.C. and Sim{\~a}o, N.M.}
}
@article {ma_shear_2020,
	title = {Shear attenuation and anelastic mechanisms in the central Pacific upper mantle},
	journal = {Earth and Planetary Science Letters},
	volume = {536},
	year = {2020},
	month = {04/2020},
	pages = {116148},
	abstract = {We determine the mantle attenuation (1/Qμ) structure beneath 70 Myr seafloors in the central Pacific. We use long-period (33-100 sec) Rayleigh waves recorded by the NoMelt array of broadband ocean-bottom seismometers. After the removal of tilt and compliance noise, we are able to measure Rayleigh wave phase and amplitude for 125 earthquakes. The compliance correction for ocean wave pressure on the seafloor is particularly important for improving signal-to-noise at periods longer than 55 sec. Attenuation and azimuthally anisotropic phase velocity in the study area are determined by approximating the wavefield as the interference of two plane waves. We find that the amplitude decay of Rayleigh waves across the NoMelt array can be adequately explained using a two-layer model: Qμ=1400 in the shallow layer, Qμ=110 in the deeper layer, and a transition depth at 70 km, although the sharpness of the transition is not well resolved by the Rayleigh wave data. Notably, Qμ observed in the NoMelt lithosphere is significantly higher than values in this area from global attenuation models. When compared with lithospheric Qμ measured at higher frequency (\~{}3 Hz), the frequency dependence of attenuation is very slight, revising previous interpretations. The effect of anelasticity on shear velocity (VS) is estimated from the ratio of observed velocity to the predicted anharmonic value. We use laboratory-based parameters to predict attenuation and velocity-dispersion spectra that result from the superposition of a weakly frequency dependent high-temperature background and an absorption peak. We test a large range of frequencies for the position of the absorption peak (fe) and determine, at each depth, which values of fe predict Qμ and VS that can fit the NoMelt Qμ and VS values simultaneously. We show that between depths of 60 and 80 km the seismic models require an increase in fe by at least 3-4 orders of magnitude. Under the assumption that the absorption peak is caused by elastically accommodated grain-boundary sliding, this increase in fe reflects a decrease in grain-boundary viscosity of 3-4 orders of magnitude. A likely explanation is an increase in the water content of the mantle, with the base of the dehydrated lid located at \~{}70-km depth.},
	keywords = {anelastic mechanism, oceanic lithosphere, Pacific Ocean, shear attenuation},
	issn = {0012-821X},
	doi = {10.1016/j.epsl.2020.116148},
	url = {https://www.sciencedirect.com/science/article/pii/S0012821X20300911},
	author = {Ma, Zhitu and Dalton, Colleen A. and Russell, Joshua B. and Gaherty, James B. and Hirth, Greg and Forsyth, Donald W.}
}
@article {117,
	title = {Temporal and spatial variations in seismic anisotropy and V P /V S ratios in a region of slow slip},
	journal = {Earth and Planetary Science Letters},
	volume = {532},
	year = {2020},
	pages = {115970},
	type = {Journal Article},
	abstract = {In September 2014, a five week long slow slip event (SSE) occurred near Gisborne at the northern Hikurangi subduction zone, New Zealand, and was recorded by offshore instruments deployed by the Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip (HOBITSS) project. Up to 25 cm of slip occurred directly below the HOBITSS array. We calculate shear wave splitting (SWS) and V P / V S ratios for event-station pairs on HOBITSS ocean bottom seismometers and onshore GeoNet seismic stations to determine the relationship in time and space between slow slip and these seismic properties. Spatial averaging of SWS fast azimuths yields trench-perpendicular fast azimuths in some areas, suggesting that compressive stress from plate convergence closes microcracks and controls anisotropy in the upper-plate. Variations from the trench perpendicular directions are observed near a subducting seamount, with directions closely resembling fracture and fault patterns created by subducting seamounts previously observed in both laboratory and field experiments. Temporal variations in fast azimuths are observed at three stations, two of which are located above the seamount, suggesting measurable variations in stress orientations. During the SSE, median V P / V S measurements across all offshore stations increase from 1.817 to 1.894 and SWS delay times decrease from 0.178 s to 0.139 s (both changes are significant within 95\% confidence intervals). Temporal variations in V P / V S and delay time are consistent with fluid pressurization below a permeability barrier and movement of fluids during the rupture of a slow-slip patch.},
	doi = {10.1016/j.epsl.2019.115970},
	url = {https://app.dimensions.ai/details/publication/pub.1123727644},
	author = {Zal, Hubert Jerzy and Jacobs, Katrina and Savage, Martha Kane and Yarce, Jefferson and Mroczek, Stefan and Graham, Kenny and Todd, Erin K. and Nakai, Jenny and Iwasaki, Yuriko and Sheehan, Anne and Mochizuki, Kimihiro and Wallace, Laura and Schwartz, Susan and Webb, Spahr and Henrys, Stuart}
}
@article {cooper_variable_2020,
	title = {Variable water input controls evolution of the Lesser Antilles volcanic arc},
	journal = {Nature},
	volume = {582},
	number = {7813},
	year = {2020},
	note = {Number: 7813 Publisher: Nature Publishing Group},
	month = {jun},
	pages = {525{\textendash}529},
	abstract = {Oceanic lithosphere carries volatiles, notably water, into the mantle through subduction at convergent plate boundaries. This subducted water exercises control on the production of magma, earthquakes, formation of continental crust and mineral resources. Identifying different potential fluid sources (sediments, crust and mantle lithosphere) and tracing fluids from their release to the surface has proved challenging1. Atlantic subduction zones are a valuable endmember when studying this deep water cycle because hydration in Atlantic lithosphere, produced by slow spreading, is expected to be highly non-uniform2. Here, as part of a multi-disciplinary project in the Lesser Antilles volcanic arc3, we studied boron trace element and isotopic fingerprints of melt inclusions. These reveal that serpentine{\textemdash}that is, hydrated mantle rather than crust or sediments{\textemdash}is a dominant supplier of subducted water to the central arc. This serpentine is most likely to reside in a set of major fracture zones subducted beneath the central arc over approximately the past ten million years. The current dehydration of these fracture zones coincides with the~current locations of the highest rates of earthquakes and prominent low shear velocities, whereas the preceding history~of~dehydration is consistent with the locations of~higher volcanic productivity and thicker arc crust. These combined geochemical and geophysical data indicate that the structure and hydration of the subducted plate are directly connected to the evolution of the arc and its associated seismic and volcanic hazards.},
	keywords = {Geochemistry, Geodynamics, Geophysics, seismology, Volcanology},
	issn = {1476-4687},
	doi = {10.1038/s41586-020-2407-5},
	url = {https://www.nature.com/articles/s41586-020-2407-5},
	author = {Cooper, George F. and Macpherson, Colin G. and Blundy, Jon D. and Maunder, Benjamin and Allen, Robert W. and Goes, Saskia and Collier, Jenny S. and Bie, Lidong and Harmon, Nicholas and Hicks, Stephen P. and Iveson, Alexander A. and Prytulak, Julie and Rietbrock, Andreas and Rychert, Catherine A. and Davidson, Jon P.}
}
@article {mark_azimuthal_2019,
	title = {Azimuthal Seismic Anisotropy of 70-Ma Pacific-Plate Upper Mantle},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {124},
	number = {2},
	year = {2019},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2018JB016451},
	month = {02/2019},
	pages = {1889{\textendash}1909},
	abstract = {Plate formation and evolution processes are predicted to generate upper mantle seismic anisotropy and negative vertical velocity gradients in oceanic lithosphere. However, predictions for upper mantle seismic velocity structure do not fully agree with the results of seismic experiments. The strength of anisotropy observed in the upper mantle varies widely. Further, many refraction studies observe a fast direction of anisotropy rotated several degrees with respect to the paleospreading direction, suggesting that upper mantle anisotropy records processes other than 2-D corner flow and plate-driven shear near mid-ocean ridges. We measure 6.0 {\textpm} 0.3\% anisotropy at the Moho in 70-Ma lithosphere in the central Pacific with a fast direction parallel to paleospreading, consistent with mineral alignment by 2-D mantle flow near a mid-ocean ridge. We also find an increase in the strength of anisotropy with depth, with vertical velocity gradients estimated at 0.02 km/s/km in the fast direction and 0 km/s/km in the slow direction. The increase in anisotropy with depth can be explained by mechanisms for producing anisotropy other than intrinsic effects from mineral fabric, such as aligned cracks or other structures. This measurement of seismic anisotropy and gradients reflects the effects of both plate formation and evolution processes on seismic velocity structure in mature oceanic lithosphere, and can serve as a reference for future studies to investigate the processes involved in lithospheric formation and evolution.},
	issn = {2169-9356},
	doi = {10.1029/2018JB016451},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018JB016451},
	author = {Mark, H. F. and Lizarralde, D. and Collins, J. A. and Miller, N. C. and Hirth, G. and Gaherty, J. B. and Evans, R. L.}
}
@article {doran_calibration_2019,
	title = {Calibration of Differential Pressure Gauges Through In Situ Testing},
	journal = {Earth and Space Science},
	volume = {6},
	number = {12},
	year = {2019},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2019EA000783},
	pages = {2663{\textendash}2670},
	abstract = {Differential pressure gauges (DPGs) are a standard component of modern broadband ocean-bottom seismometer instruments and have proven useful for observing a wide range of seismic and oceanographic phenomena. However, the response function of the DPG remains poorly known, limiting our ability to recover amplitude and phase information from seafloor pressure signals with high fidelity. The sensitivity and long-period response are difficult to calibrate in the lab, as they are known to vary with temperature and pressure and perhaps between sensors of the same design. We present the results of a field experiment designed to determine empirical response functions in situ by inducing a pre-defined pressure offset on a deployed instrument. The results compare favorably with calibrations estimated independently through post-deployment data analyses. Our study demonstrates that observed response functions can deviate from the nominal response by a factor of two or greater with regards to both the sensitivity and the time constant. Incorporating calibration devices such as those described here into future deployments may prove to be a cost-effective way to improve the accuracy and utility of differential pressure data.},
	issn = {2333-5084},
	doi = {10.1029/2019EA000783},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019EA000783},
	author = {Doran, A.k. and Rapa, M. and Laske, G. and Babcock, J. and McPeak, S.}
}
@article {lynner_eastern_2019,
	title = {The Eastern North American Margin Community Seismic Experiment: An Amphibious Active- and Passive-Source Dataset},
	journal = {Seismological Research Letters},
	volume = {91},
	number = {1},
	year = {2019},
	month = {10/2019},
	pages = {533{\textendash}540},
	abstract = {The eastern North American margin community seismic experiment (ENAM-CSE) was conceived to target the ENAM Geodynamic Processes at Rifting and Subducting Margins (GeoPRISMS) primary site with a suite of both active- and passive-source seismic data that would shed light on the processes associated with rift initiation and evolution. To fully understand the ENAM, it was necessary to acquire a seismic dataset that was both amphibious, spanning the passive margin from the continental interior onto the oceanic portion of the North American plate, and multiresolution, enabling imaging of the sediments, crust, and mantle lithosphere. The ENAM-CSE datasets were collected on- and offshore of North Carolina and Virginia over a series of cruises and land-based deployments between April 2014 and June 2015. The passive-source component of the ENAM-CSE included 30 broadband ocean-bottom seismometers (OBSs) and 3 onshore broadband instruments. The broadband stations were deployed contemporaneously with those of the easternmost EarthScope Transportable Array creating a trans-margin amphibious seismic dataset. The active-source portion of the ENAM-CSE included several components: (1)~two onshore wide-angle seismic profiles where explosive shots were recorded on closely spaced geophones; (2)~four major offshore wide-angle seismic profiles acquired with an airgun source and short-period OBSs (SPOBSs), two of which were extended onland by deployments of short-period seismometers; (3)~marine multichannel seismic (MCS) data acquired along the four lines of SPOBSs and a series of other profiles along and across the margin. During the cruises, magnetic, gravity, and bathymetric data were also collected along all MCS profiles. All of the ENAM-CSE products were made publicly available shortly after acquisition, ensuring unfettered community access to this unique dataset.},
	issn = {0895-0695},
	doi = {10.1785/0220190142},
	url = {https://doi.org/10.1785/0220190142},
	author = {Lynner, Colton and J. A. Van Avendonk, Harm and B{\'e}cel, Anne and Christeson, Gail L. and Dugan, Brandon and Gaherty, James B. and Harder, Steven and Hornbach, Matthew J. and Lizarralde, Daniel and Long, Maureen D. and Magnani, M. Beatrice and Shillington, Donna J. and Aderhold, Kasey and Eilon, Zachary C. and Wagner, Lara S.}
}
@article {warren-smith_episodic_2019,
	title = {Episodic stress and fluid pressure cycling in subducting oceanic crust during slow slip},
	journal = {Nature Geoscience},
	volume = {12},
	number = {6},
	year = {2019},
	note = {Number: 6 Publisher: Nature Publishing Group},
	month = {jun},
	pages = {475{\textendash}481},
	abstract = {Slow slip events are part of a spectrum of aseismic processes that relieve tectonic stress on faults. Their spatial distribution in subduction zones has been linked to perturbations in fluid pressure within the megathrust shear zone and subducting oceanic crust. However, physical observations of temporal fluid pressure fluctuations through slow slip cycles remain elusive. Here, we use earthquake focal mechanisms recorded on an ocean-bottom seismic network to show that crustal stresses and fluid pressures within subducting oceanic crust evolve before and during slow slip events. Specifically, we observe that the retrieved stress ratio, which describes the relative magnitudes of the principal compressive stresses, systematically decreases before slow slip events in New Zealand{\textquoteright}s northern Hikurangi subduction zone, and subsequently increases during the evolution of each slow slip event. We propose that these changes represent the accumulation and release of fluid pressure within overpressured subducting oceanic crust, the episodicity of which may influence the timing of slow slip event occurrence on subduction megathrusts. This work contributes an improved understanding of the physical driving forces underlying slow subduction earthquakes, and a potential means by which to monitor stress and fluid pressure accumulation in such regions.},
	keywords = {seismology, Tectonics},
	issn = {1752-0908},
	doi = {10.1038/s41561-019-0367-x},
	url = {https://www.nature.com/articles/s41561-019-0367-x},
	author = {Warren-Smith, E. and Fry, B. and Wallace, L. and Chon, E. and Henrys, S. and Sheehan, A. and Mochizuki, K. and Schwartz, S. and Webb, S. and Lebedev, S.}
}
@article {fredrickson_optimizing_2019,
	title = {Optimizing Sensor Configurations for the Detection of Slow-Slip Earthquakes in Seafloor Pressure Records, Using the Cascadia Subduction Zone as a Case Study},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {124},
	number = {12},
	year = {2019},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2019JB018053},
	pages = {13504{\textendash}13531},
	abstract = {We present seafloor pressure records from the Cascadia Subduction Zone, alongside oceanographic and geophysical models, to evaluate the spatial uniformity of bottom pressure and optimize the geometry of sensor networks for resolving offshore slow-slip transients. Seafloor pressure records from 2011 to 2015 show that signal amplitudes are depth-dependent, with tidally filtered and detrended root-mean-squares of <2 cm on the abyssal plain and >6 cm on the continental shelf. This is consistent with bottom pressure predictions from circulation models and comparable to deformation amplitudes from offshore slow slip observed in other subduction zones. We show that the oceanographic component of seafloor pressure can be reduced to <=1-cm root-mean-square by differencing against a reference record from a similar depth, under restrictions that vary with depth. Instruments at 100{\textendash}250 m require depths matched within 10 m at separations of <100 km, while locations deeper than 1,400 m are broadly comparable over separations of at least 300 km. Despite the significant noise reduction from this method, no slow slip was identified in the dataset, possibly due to poor spatiotemporal instrument coverage, nonideal deployment geometry, and limited depth-matched instruments. We use forward predictions of deformation from elastic half-space models and hindcast pressure from circulation models to generate synthetic slow-slip observational records and show that a range of slip scenarios produce resolvable signals under depth-matched differencing. For future detection of offshore slow slip in Cascadia, we recommend a geometry in which instruments are deployed along isobaths to optimize corrections for oceanographic signals.},
	keywords = {Cascadia Subduction Zone, geodesy, ocean circulation, seafloor pressure, slow-slip earthquake},
	issn = {2169-9356},
	doi = {10.1029/2019JB018053},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JB018053},
	author = {Fredrickson, Erik K. and Wilcock, William S. D. and Schmidt, David A. and MacCready, Parker and Roland, Emily and Kurapov, Alexander L. and Zumberge, Mark A. and Sasagawa, Glenn S.}
}
@article {trehu_post-seismic_2019,
	title = {Post-seismic response of the outer accretionary prism after the 2010 Maule earthquake, Chile},
	journal = {Geosphere},
	volume = {16},
	number = {1},
	year = {2019},
	month = {dec},
	pages = {13{\textendash}32},
	abstract = {To investigate the dynamic response of the outer accretionary prism updip from the patch of greatest slip during the 2010 Mw 8.8 Maule earthquake (Chile), 10 ocean-bottom seismometers (OBSs) were deployed from May 2012 to March 2013 in a small network with an inter-instrument spacing of 7{\textendash}10 km. Nine were recovered, with four recording data from intermediate-band three-component seismometers and differential pressure gauges, and five recording data from absolute pressure gauges (APGs). All instruments were also equipped with fluid flow meters designed to detect very low rates of flow into or out of the seafloor. We present hypocenters for local earthquakes that have S-P times \&lt;17 s (i.e., within \~{}125 km of the network), with a focus on events located beneath or near the network. Most of the seismicity occurred either near the boundary between the active accretionary prism and continental basement or in the outer rise seaward of the trench. For many outer-rise earthquakes, the P and S arrivals are followed by a distinctive T-phase arrival. Very few earthquakes, and none located with hypocenters deemed {\textquotedblleft}reliable,{\textquotedblright} were located within the active accretionary prism or on the underlying plate boundary. Nonvolcanic tremor-like pulses and seafloor pressure transients (but no very-low-frequency earthquakes or fluid flow) were also detected. Many of the tremor observations are likely T-phases or reverberations due to soft seafloor sediments, although at least one episode may have originated within the accretionary prism south of the network. The transient seafloor pressure changes were observed simultaneously on three APGs located over the transition from the active prism to the continental basement and show polarity changes over short distances, suggesting a shallow source. Their duration of several hours to days is shorter than most geodetic transients observed using onshore GPS networks. The results demonstrate the need for densely spaced and large-aperture OBS networks equipped with APGs for understanding subduction zone behavior.},
	issn = {1553-040X},
	doi = {10.1130/GES02102.1},
	url = {https://doi.org/10.1130/GES02102.1},
	author = {Tr{\'e}hu, Anne M. and de Moor, Alexander and Madrid, Jos{\'e} Mieres and S{\'a}ez, Miguel and Chadwell, C. David and Ortega-Culaciati, Francisco and Ruiz, Javier and Ruiz, Sergio and Tryon, Michael D.}
}
@article {Hooft2019,
	title = {Seismic imaging of Santorini: Subsurface constraints on caldera collapse and present-day magma recharge},
	journal = {Earth and Planetary Science Letters},
	volume = {514},
	year = {2019},
	month = {may},
	pages = {48{\textendash}61},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2019.02.033},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X19301360},
	author = {Hooft, E.E.E. and Heath, B.A. and Toomey, D.R. and Paulatto, M. and Papazachos, C.B. and Nomikou, P. and Morgan, J.V. and Warner, M.R.}
}
@article {merz_seismicity_2019,
	title = {Seismicity and Velocity Structure of Lo{\textquoteright}ihi Submarine Volcano and Southeastern Hawai{\textquoteright}i},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {124},
	number = {11},
	year = {2019},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2019JB018168},
	pages = {11380{\textendash}11393},
	abstract = {Hundreds of earthquakes were recorded during a nine-month ocean bottom seismometer deployment surrounding Lo{\textquoteright}ihi submarine volcano, Hawai{\textquoteright}i. The 12-station ocean bottom seismometer network widened the aperture of earthquake detection around the Big Island, allowing better constraints on the location of seismicity offshore Hawai{\textquoteright}i. Although this deployment occurred during a time of volcanic quiescence for Lo{\textquoteright}ihi, it establishes an important basis for background seismicity of the volcano. Offshore seismicity during this study was dominated by events located in the mantle fault zone at depths of 25{\textendash}40 km. These events reflect rupture on preexisting faults in the lower lithosphere caused by stresses induced by volcano loading and flexure of the Pacific Plate (Pritchard et al., 2007, https://doi.org/10.1111/j.1365-246X.2006.03169.x; Wolfe et al., 2004, https://doi.org/10.1029/2003GC000618). Tomography was performed using double-difference seismic tomography and showed shallow velocities to be slower than the regional velocity model (HG50; Klein, 1981, https://pubs.geoscienceworld.org/ssa/bssa/article/71/5/1503/118231/A-linear-gradient-crustal-model-for-south-Hawaii). A broad, low-velocity anomaly was observed from 20{\textendash}40-km depth, and is suggestive of the central plume conduit that supplies magma to Lo{\textquoteright}ihi and the active volcanoes of the Big Island. A localized high-velocity body is observed 4{\textendash}6-km depth beneath Lo{\textquoteright}ihi{\textquoteright}s summit, extending 10 km to the north and south. Following Lo{\textquoteright}ihi{\textquoteright}s active rift zones and crossing the summit, this high-velocity body is characteristic of intrusive material. Two low-velocity anomalies are observed below the oceanic crust, interpreted as melt accumulation beneath Lo{\textquoteright}ihi and magmatic underplating beneath Hawai{\textquoteright}i Island.},
	keywords = {Hawai{\textquoteright}i, hot spot, Lo{\textquoteright}ihi seamount, tomography, volcano seismology},
	issn = {2169-9356},
	doi = {10.1029/2019JB018168},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JB018168},
	author = {Merz, D. K. and Caplan-Auerbach, J. and Thurber, C. H.}
}
@article {yarce_seismicity_2019,
	title = {Seismicity at the Northern Hikurangi Margin, New Zealand, and Investigation of the Potential Spatial and Temporal Relationships With a Shallow Slow Slip Event},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {124},
	number = {5},
	year = {2019},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2018JB017211},
	pages = {4751{\textendash}4766},
	abstract = {In 2014{\textendash}2015, the Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip experiment deployed seafloor absolute pressure gauges and ocean bottom seismometers directly above a large slow slip event, allowing examination of the relationship between slow slip and earthquakes in detail. Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip data were combined with nearby existing land stations to create a catalog of microseismicity consisting of 2,300 earthquakes ranging in magnitude between 0.5 and 4.7 that is complete to magnitude 1.5, yielding almost twice as many events as detected by the onshore networks alone. This greatly improves the seismicity catalog for this active subduction zone margin, especially in the offshore portion that was difficult to study using only the inland permanent seismic network. The new locations for the events within the footprint of the offshore network show that earthquakes near the trench are systematically shallower than and NW (landward) of their locations using only land-based stations. Our results indicate that Hikurangi seismicity is concentrated in two NE-SW bands, one offshore beneath the outer forearc wedge, one onshore beneath the eastern Raukumara Peninsula, and the majority of earthquakes are within the subducting Pacific plate with a smaller percent at the plate interface. We find a 20-km wide northeast trending gap in microseismicity between the two bands and beneath the inner forearc wedge and this gap in seismicity borders the downdip edge of a slow slip patch.},
	keywords = {gap, Hikurangi, ocean bottom seismometers, seismicity, slow slip},
	issn = {2169-9356},
	doi = {10.1029/2018JB017211},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018JB017211},
	author = {Yarce, J. and Sheehan, A. F. and Nakai, J. S. and Schwartz, S. Y. and Mochizuki, K. and Savage, M. K. and Wallace, L. M. and Henrys, S. A. and Webb, S. C. and Ito, Y. and Abercrombie, R. E. and Fry, B. and Shaddox, H. and Todd, E. K.}
}
@article {Heath2019,
	title = {Tectonism and Its Relation to Magmatism Around Santorini Volcano From Upper Crustal P Wave Velocity},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {124},
	number = {10},
	year = {2019},
	month = {oct},
	pages = {10610{\textendash}10629},
	issn = {2169-9313},
	doi = {10.1029/2019JB017699},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JB017699},
	author = {Heath, B. A. and Hooft, E. E. E. and Toomey, D. R. and Papazachos, C. B. and Nomikou, P. and Paulatto, M. and Morgan, J. V. and Warner, M. R.}
}
@article {wang_tsunami_2019,
	title = {Tsunami Data Assimilation Without a Dense Observation Network},
	journal = {Geophysical Research Letters},
	volume = {46},
	number = {4},
	year = {2019},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2018GL080930},
	pages = {2045{\textendash}2053},
	abstract = {The tsunami data assimilation method enables tsunami forecasting directly from observations, without the need of estimating tsunami sources. However, it requires a dense observation network to produce desirable results. Here we propose a modified method of tsunami data assimilation for regions with a sparse observation network. The method utilizes interpolated waveforms at virtual stations. The tsunami waveforms at the virtual stations between two existing observation stations are estimated by shifting arrival times with the linear interpolation of observed arrival times and by correcting the amplitudes for their water depths. In our new data assimilation approach, we employ the Optimal Interpolation algorithm to both the real observations and virtual stations, in order to construct a complete wavefront of tsunami propagation. The application to the 2004 Sumatra-Andaman earthquake and the 2009 Dusky Sound, New Zealand, earthquake reveals that addition of virtual stations greatly helps improve the tsunami forecasting accuracy.},
	keywords = {data assimilation, tsunami forecasting},
	issn = {1944-8007},
	doi = {10.1029/2018GL080930},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GL080930},
	author = {Wang, Y. and Maeda, T. and Satake, K. and Heidarzadeh, M. and Su, H. and Sheehan, A. F. and Gusman, A. R.}
}
@article {Accardo2018,
	title = {Constraints on Rift Basin Structure and Border Fault Growth in the Northern Malawi Rift From 3-D Seismic Refraction Imaging},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {123},
	number = {11},
	year = {2018},
	month = {nov},
	pages = {10,003{\textendash}10,025},
	issn = {21699313},
	doi = {10.1029/2018JB016504},
	url = {http://doi.wiley.com/10.1029/2018JB016504},
	author = {Accardo, N. J. and Shillington, D. J. and Gaherty, J. B. and Scholz, C. A. and Nyblade, A. A. and Chindandali, P. R. N. and Kamihanda, G. and McCartney, T. and Wood, D. and Wambura Ferdinand, R.}
}
@article {todd_earthquakes_2018,
	title = {Earthquakes and Tremor Linked to Seamount Subduction During Shallow Slow Slip at the Hikurangi Margin, New Zealand},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {123},
	number = {8},
	year = {2018},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2018JB016136},
	pages = {6769{\textendash}6783},
	abstract = {Shallow slow slip events have been well documented offshore Gisborne at the northern Hikurangi subduction margin, New Zealand, and are associated with tectonic tremor downdip of the slow slip patch and increases in local microseismicity. Tremor and seismicity on the shallow subduction interface are often poorly resolved due to their distance from land-based seismic and geodetic networks. To address this shortcoming, the Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip experiment deployed 24 absolute pressure gauges and 15 ocean bottom seismometers on the seafloor above the Gisborne slow slip patch to investigate the spatial and temporal extent of slow slip and associated tremor and earthquake activity. We present a detailed spatiotemporal analysis of the seismic signatures of various interplate slip processes associated with the September/October 2014 Gisborne slow slip event. Tectonic tremor begins toward the end and continues after the geodetically constrained slow slip event and is localized in the vicinity of two subducted seamounts within and updip of the slow slip patch. The subsequent, rather than synchronous occurrence of tremor suggests that tremor may be triggered by stress changes induced by slow slip. However, Coulomb failure stress change models based on the slow slip distribution fail to predict the location of tremor, suggesting that seamount subduction plays a dominant role in the stress state of the shallow megathrust. This and the observed interplay of seismic and aseismic interplate slip processes imply that stress changes from slow slip play a secondary role in the distribution of associated microseismicity.},
	keywords = {earthquake, New Zealand, Seamount, slow slip, subduction, tremor},
	issn = {2169-9356},
	doi = {10.1029/2018JB016136},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018JB016136},
	author = {Todd, Erin K. and Schwartz, Susan Y. and Mochizuki, Kimihiro and Wallace, Laura M. and Sheehan, Anne F. and Webb, Spahr C. and Williams, Charles A. and Nakai, Jenny and Yarce, Jefferson and Fry, Bill and Henrys, Stuart and Ito, Yoshihiro}
}
@article {Gong2018,
	title = {Interactions between strike-slip earthquakes and the subduction interface near the Mendocino Triple Junction},
	journal = {Earth and Planetary Science Letters},
	volume = {482},
	year = {2018},
	month = {jan},
	pages = {414{\textendash}422},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2017.11.022},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X17306581},
	author = {Gong, Jianhua and McGuire, Jeffrey J.}
}
@article {morton_newly_2018,
	title = {Newly detected earthquakes in the Cascadia subduction zone linked to seamount subduction and deformed upper plate},
	journal = {Geology},
	volume = {46},
	number = {11},
	year = {2018},
	month = {09/2018},
	pages = {943{\textendash}946},
	abstract = {Data from an amphibious seismic network in Cascadia (northwest North America) provide unique near-source observations to assess the influence of subducting topography on seismicity. Using subspace detection, we detect and locate 222 events in two separate clusters, near a subducted seamount and a possibly accreted seamount. Seismicity in both clusters is largely shallower than the plate interface and exhibits occasional swarm-like behavior. This implies that the seamount is subducting aseismically via weak coupling with the overriding plate, while earthquakes in the upper plate arise from a high degree of fracturing due to seamount interaction, and the accreted seamount induced similar fracturing before off-scraping.},
	issn = {0091-7613},
	doi = {10.1130/G45354.1},
	url = {https://doi.org/10.1130/G45354.1},
	author = {Morton, Emily A. and Bilek, Susan L. and Rowe, Charlotte A.}
}
@article {moyer_spatial_2018,
	title = {Spatial and Temporal Variations in Earthquake Stress Drop on Gofar Transform Fault, East Pacific Rise: Implications for Fault Strength},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {123},
	number = {9},
	year = {2018},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2018JB015942},
	pages = {7722{\textendash}7740},
	abstract = {On Gofar Transform Fault on the East Pacific Rise, the largest earthquakes (6.0 <= MW <= 6.2) have repeatedly ruptured the same portion of the fault, while intervening fault segments host swarms of microearthquakes. These long-term patterns in earthquake occurrence suggest that heterogeneous fault zone properties control earthquake behavior. Using waveforms from ocean bottom seismometers that recorded seismicity before and after an anticipated 2008 MW 6.0 mainshock, we investigate the role that differences in material properties have on earthquake rupture at Gofar. We determine stress drop for 138 earthquakes (2.3 <= MW <= 4.0) that occurred within and between the rupture areas of large earthquakes. Stress drops are calculated from corner frequencies derived using an empirical Green{\textquoteright}s function spectral ratio method, and seismic moments are obtained by fitting the omega-square source model to the low frequency amplitude of the displacement spectrum. Our analysis yields stress drops from 0.04 to 3.2 MPa with statistically significant spatial variation, including 2 times higher average stress drop in fault segments where large earthquakes also occur compared to fault segments that host earthquake swarms. We find an inverse correlation between stress drop and P wave velocity reduction, which we interpret as the effect of fault zone damage on the ability of the fault to store strain energy that leads to our spatial variations in stress drop. Additionally, we observe lower stress drops following the MW 6.0 mainshock, consistent with increased damage and decreased fault strength after a large earthquake.},
	keywords = {earthquake stress drop, earthquake swarms, fault zone damage, oceanic transform faults, rupture dynamics, seismic coupling},
	issn = {2169-9356},
	doi = {10.1029/2018JB015942},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018JB015942},
	author = {Moyer, Pamela A. and Boettcher, Margaret S. and McGuire, Jeffery J. and Collins, John A.}
}
@article {Mousavi2017,
	title = {Automatic noise-removal/signal-removal based on general cross-validation thresholding in synchrosqueezed domain and its application on earthquake data},
	journal = {GEOPHYSICS},
	volume = {82},
	number = {4},
	year = {2017},
	month = {jul},
	pages = {V211{\textendash}V227},
	issn = {0016-8033},
	doi = {10.1190/geo2016-0433.1},
	url = {http://library.seg.org/doi/10.1190/geo2016-0433.1},
	author = {Mousavi, S. Mostafa and Langston, Charles A.}
}
@article {Cattania2017,
	title = {Dynamic triggering and earthquake swarms on East Pacific Rise transform faults},
	journal = {Geophysical Research Letters},
	volume = {44},
	number = {2},
	year = {2017},
	month = {jan},
	pages = {702{\textendash}710},
	issn = {0094-8276},
	doi = {10.1002/2016GL070857},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2016GL070857},
	author = {Cattania, Camilla and McGuire, Jeffrey J. and Collins, John A.}
}
@article {Sohn2017,
	title = {Exploring the Restless Floor of Yellowstone Lake},
	journal = {Eos},
	year = {2017},
	month = {dec},
	abstract = {Yellowstone Lake, far from any ocean, hosts underwater hot springs similar to those on mid-ocean ridges. A research team is investigating the processes that drive the lake{\textquoteright}s hydrothermal systems.},
	issn = {2324-9250},
	doi = {10.1029/2017EO087035},
	url = {https://eos.org/project-updates/exploring-the-restless-floor-of-yellowstone-lake},
	author = {Sohn, Robert and Harris, Robert and Linder, Chris and Luttrell, Karen and Lovalvo, David and Morgan, Lisa and Seyfried, William and Shanks, Pat}
}
@article {Wang2017,
	title = {Green{\textquoteright}s Function-Based Tsunami Data Assimilation: A Fast Data Assimilation Approach Toward Tsunami Early Warning},
	journal = {Geophysical Research Letters},
	volume = {44},
	number = {20},
	year = {2017},
	month = {oct},
	pages = {10,282{\textendash}10,289},
	issn = {00948276},
	doi = {10.1002/2017GL075307},
	url = {http://doi.wiley.com/10.1002/2017GL075307},
	author = {Wang, Yuchen and Satake, Kenji and Maeda, Takuto and Gusman, Aditya Riadi}
}
@article {Flores2017,
	title = {Observations of Seismicity and Ground Motion in the Northeast U.S. Atlantic Margin from Ocean-Bottom Seismometer Data},
	journal = {Seismological Research Letters},
	volume = {88},
	number = {1},
	year = {2017},
	month = {jan},
	pages = {23{\textendash}31},
	issn = {0895-0695},
	doi = {10.1785/0220160079},
	url = {https://pubs.geoscienceworld.org/srl/article/88/1/23-31/314313},
	author = {Flores, Claudia H. and ten Brink, Uri S. and McGuire, Jeffrey J. and Collins, John A.}
}
@article {Arnoux2017,
	title = {Seismic evidence that black smoker heat flux is influenced by localized magma replenishment and associated increases in crustal permeability},
	journal = {Geophysical Research Letters},
	volume = {44},
	number = {4},
	year = {2017},
	month = {feb},
	pages = {1687{\textendash}1695},
	issn = {00948276},
	doi = {10.1002/2016GL071990},
	url = {http://doi.wiley.com/10.1002/2016GL071990},
	author = {Arnoux, Gillean M. and Toomey, Douglas R. and Hooft, Emilie E. E. and Wilcock, William S. D. and Morgan, Joanna and Warner, Mike and VanderBeek, Brandon P.}
}
@article {Accardo2017,
	title = {Surface wave imaging of the weakly extended Malawi Rift from ambient-noise and teleseismic Rayleigh waves from onshore and lake-bottom seismometers},
	journal = {Geophysical Journal International},
	volume = {209},
	number = {3},
	year = {2017},
	month = {jun},
	pages = {1892{\textendash}1905},
	issn = {0956-540X},
	doi = {10.1093/gji/ggx133},
	url = {https://academic.oup.com/gji/article/209/3/1892/3098113},
	author = {Accardo, N.J. and Gaherty, J.B. and Shillington, D.J. and Ebinger, C.J. and Nyblade, A.A. and Mbogoni, G.J. and Chindandali, P.R.N. and Ferdinand, R.W. and Mulibo, G.D. and Kamihanda, G. and Keir, D. and Scholz, C. and Selway, K. and O{\textquoteright}Donnell, J.P. and Tepp, G. and Gallacher, R. and Mtelela, K. and Salima, J. and Mruma, A.}
}
@article {An2017,
	title = {Theoretical Solution and Applications of Ocean Bottom Pressure Induced by Seismic Seafloor Motion},
	journal = {Geophysical Research Letters},
	volume = {44},
	number = {20},
	year = {2017},
	month = {oct},
	pages = {10,272{\textendash}10,281},
	issn = {00948276},
	doi = {10.1002/2017GL075137},
	url = {http://doi.wiley.com/10.1002/2017GL075137},
	author = {An, Chao and Cai, Chen and Zheng, Yong and Meng, Lingsen and Liu, Philip}
}
@article {Shillington2016,
	title = {Acquisition of a Unique Onshore/Offshore Geophysical and Geochemical Dataset in the Northern Malawi (Nyasa) Rift},
	journal = {Seismological Research Letters},
	volume = {87},
	number = {6},
	year = {2016},
	month = {nov},
	pages = {1406{\textendash}1416},
	issn = {0895-0695},
	doi = {10.1785/0220160112},
	url = {https://pubs.geoscienceworld.org/srl/article/87/6/1406-1416/314187},
	author = {Shillington, Donna J. and Gaherty, James B. and Ebinger, Cynthia J. and Scholz, Christopher A. and Selway, Kate and Nyblade, Andrew A. and Bedrosian, Paul A. and Class, Cornelia and Nooner, Scott L. and Pritchard, Matthew E. and Elliott, Julie and Chindandali, Patrick R. N. and Mbogoni, Gaby and Ferdinand, Richard Wambura and Boniface, Nelson and Manya, Shukrani and Kamihanda, Godson and Saria, Elifuraha and Mulibo, Gabriel and Salima, Jalf and Mruma, Abdul and Kalindekafe, Leonard and Accardo, Natalie J. and Ntambila, Daud and Kachingwe, Marsella and Mesko, Gary T. and McCartney, Tannis and Maquay, Melania and O{\textquoteright}Donnell, J. P. and Tepp, Gabrielle and Mtelela, Khalfan and Trinhammer, Per and Wood, Douglas and Aaron, Ernest and Gibaud, Mark and Rapa, Martin and Pfeifer, Cathy and Mphepo, Felix and Gondwe, Duncan and Arroyo, Gabriella and Eddy, Celia and Kamoga, Brian and Moshi, Mary}
}
@article {Harris2016,
	title = {Investigations of Shallow Slow Slip Offshore of New Zealand},
	journal = {Eos},
	volume = {97},
	year = {2016},
	month = {mar},
	abstract = {Recent and upcoming studies of the Hikurangi margin east of New Zealand shed light on previously undetectable tectonic movements.},
	issn = {2324-9250},
	doi = {10.1029/2016EO048945},
	url = {https://eos.org/project-updates/investigations-of-shallow-slow-slip-offshore-of-new-zealand},
	author = {Harris, Robert and Wallace, Laura and Webb, Spahr and Ito, Yoshihiro and Mochizuki, Kimihiro and Ichihara, Hiroshi and Henrys, Stuart and Tr{\'e}hu, Anne and Schwartz, Susan and Sheehan, Anne and Saffer, Demian and Lauer, Rachel}
}
@article {Chen2016a,
	title = {Measuring earthquake source parameters in the Mendocino triple junction region using a dense OBS array: Implications for fault strength variations},
	journal = {Earth and Planetary Science Letters},
	volume = {453},
	year = {2016},
	month = {nov},
	pages = {276{\textendash}287},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2016.08.022},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X16304459},
	author = {Chen, Xiaowei and McGuire, Jeffrey J.}
}
@article {Morgan2016,
	title = {Next-generation seismic experiments {\textendash} II: wide-angle, multi-azimuth, 3-D, full-waveform inversion of sparse field data},
	journal = {Geophysical Journal International},
	volume = {204},
	number = {2},
	year = {2016},
	month = {feb},
	pages = {1342{\textendash}1363},
	issn = {0956-540X},
	doi = {10.1093/gji/ggv513},
	url = {https://academic.oup.com/gji/article-lookup/doi/10.1093/gji/ggv513},
	author = {Morgan, Joanna and Warner, Michael and Arnoux, Gillean and Hooft, Emilie and Toomey, Douglas and VanderBeek, Brandon and Wilcock, William}
}
@article {Wallace2016,
	title = {Slow slip near the trench at the Hikurangi subduction zone, New Zealand},
	journal = {Science},
	volume = {352},
	number = {6286},
	year = {2016},
	month = {may},
	pages = {701{\textendash}704},
	issn = {0036-8075},
	doi = {10.1126/science.aaf2349},
	url = {https://www.sciencemag.org/lookup/doi/10.1126/science.aaf2349},
	author = {Wallace, L. M. and Webb, S. C. and Ito, Y. and Mochizuki, K. and Hino, R. and Henrys, S. and Schwartz, S. Y. and Sheehan, A. F.}
}
@article {Zietlow2016,
	title = {Teleseismic P wave tomography of South Island, New Zealand upper mantle: Evidence of subduction of Pacific lithosphere since 45 Ma},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {121},
	number = {6},
	year = {2016},
	month = {jun},
	pages = {4427{\textendash}4445},
	issn = {21699313},
	doi = {10.1002/2015JB012624},
	url = {http://doi.wiley.com/10.1002/2015JB012624},
	author = {Zietlow, Daniel W. and Molnar, Peter H. and Sheehan, Anne F.}
}
@article {Gusman2016,
	title = {Tsunami data assimilation of Cascadia seafloor pressure gauge records from the 2012 Haida Gwaii earthquake},
	journal = {Geophysical Research Letters},
	volume = {43},
	number = {9},
	year = {2016},
	month = {may},
	pages = {4189{\textendash}4196},
	issn = {00948276},
	doi = {10.1002/2016GL068368},
	url = {http://doi.wiley.com/10.1002/2016GL068368},
	author = {Gusman, Aditya Riadi and Sheehan, Anne F. and Satake, Kenji and Heidarzadeh, Mohammad and Mulia, Iyan Eka and Maeda, Takuto}
}
@article {Masy2015,
	title = {Lithospheric expression of cenozoic subduction, mesozoic rifting and the Precambrian Shield in Venezuela},
	journal = {Earth and Planetary Science Letters},
	volume = {410},
	year = {2015},
	month = {jan},
	pages = {12{\textendash}24},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2014.08.041},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X14005652},
	author = {Masy, Jeniffer and Niu, Fenglin and Levander, Alan and Schmitz, Michael}
}
@article {Martin-Short2015,
	title = {Mantle flow geometry from ridge to trench beneath the Gorda{\textendash}Juan de Fuca plate system},
	journal = {Nature Geoscience},
	volume = {8},
	number = {12},
	year = {2015},
	month = {dec},
	pages = {965{\textendash}968},
	issn = {1752-0894},
	doi = {10.1038/ngeo2569},
	url = {http://www.nature.com/articles/ngeo2569},
	author = {Martin-Short, Robert and Allen, Richard M. and Bastow, Ian D. and Totten, Eoghan and Richards, Mark A.}
}
@article {Eakin2015,
	title = {New geophysical constraints on a failed subduction initiation: The structure and potential evolution of the Gagua Ridge and Huatung Basin},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {16},
	number = {2},
	year = {2015},
	month = {feb},
	pages = {380{\textendash}400},
	issn = {15252027},
	doi = {10.1002/2014GC005548},
	url = {http://doi.wiley.com/10.1002/2014GC005548},
	author = {Eakin, Daniel H. and McIntosh, Kirk D. and Van Avendonk, H. J. A. and Lavier, Luc}
}
@article {Morton2015,
	title = {Preliminary Event Detection of Earthquakes Using the Cascadia Initiative Data},
	journal = {Seismological Research Letters},
	volume = {86},
	number = {5},
	year = {2015},
	month = {sep},
	pages = {1270{\textendash}1277},
	issn = {0895-0695},
	doi = {10.1785/0220150098},
	url = {https://pubs.geoscienceworld.org/srl/article/86/5/1270-1277/315541},
	author = {Morton, Emily A. and Bilek, Susan L.}
}
@article {Menke2015,
	title = {Seismic anisotropy indicates ridge-parallel asthenospheric flow beneath the Eastern Lau Spreading Center},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {120},
	number = {2},
	year = {2015},
	month = {feb},
	pages = {976{\textendash}992},
	issn = {2169-9313},
	doi = {10.1002/2014JB011154},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2014JB011154},
	author = {Menke, William and Zha, Yang and Webb, Spahr C. and Blackman, Donna K.}
}
@article {toomey_cascadia_2014,
	title = {THE CASCADIA INITIATIVE: A Sea Change In Seismological Studies of Subduction Zones},
	journal = {Oceanography},
	volume = {27},
	number = {2},
	year = {2014},
	note = {Publisher: Oceanography Society},
	pages = {138{\textendash}150},
	abstract = {ABSTRACTIncreasing public awareness that the Cascadia subduction zone in the Pacific Northwest is capable of great earthquakes (magnitude 9 and greater) motivates the Cascadia Initiative, an ambitious onshore/offshore seismic and geodetic experiment that takes advantage of an amphibious array to study questions ranging from megathrust earthquakes, to volcanic arc structure, to the formation, deformation and hydration of the Juan De Fuca and Gorda Plates. Here, we provide an overview of the Cascadia Initiative, including its primary science objectives, its experimental design and implementation, and a preview of how the resulting data are being used by a diverse and growing scientific community. The Cascadia Initiative also exemplifies how new technology and community-based experiments are opening up frontiers for marine science. The new technology{\textemdash}shielded ocean bottom seismometers{\textemdash}is allowing more routine investigation of the source zone of megathrust earthquakes, which almost exclusively lies offshore and in shallow water. The Cascadia Initiative offers opportunities and accompanying challenges to a rapidly expanding community of those who use ocean bottom seismic data.},
	issn = {1042-8275},
	doi = {10.5670/oceanog.2014.49},
	url = {https://www.jstor.org/stable/24862164},
	author = {Toomey, Douglas R. and Allen, Richard M. and Barclay, Andrew H. and Bell, Samuel W. and Bromirski, Peter D. and Carlson, Richard L. and Chen, Xiaowei and Collins, John A. and Dziak, Robert P. and Evers, Brent and Forsyth, Donald W. and Gerstoft, Peter and Hooft, Emilie E.E. and Livelybrooks, Dean and Lodewyk, Jessica A. and Luther, Douglas S. and McGuire, Jeffrey J. and Schwartz, Susan Y. and Tolstoy, Maya and Tr{\'e}hu, Anne M. and Weirathmueller, Michelle and Wilcock, William S.D.}
}
@article {gouedard_correction_2014,
	title = {Correction of Ocean-Bottom Seismometer Instrumental Clock Errors Using Ambient Seismic Noise},
	journal = {Bulletin of the Seismological Society of America},
	volume = {104},
	number = {3},
	year = {2014},
	month = {apr},
	pages = {1276{\textendash}1288},
	abstract = {Very accurate timing of seismic recordings is critical for modern processing techniques. Clock synchronization among the instruments constituting an array is, however, difficult without direct communication between them. Synchronization to Global Positioning System (GPS) time is one option for on-land deployments, but not for underwater surveys as electromagnetic signals do not propagate efficiently in water. If clock drift is linear, time corrections for ocean-bottom seismometer (OBS) deployments can be estimated through GPS synchronization before and after the deployment, but this is not sufficient for many applications as the nonlinear component of the drift can reach tens to hundreds of milliseconds for long-duration experiments. We present two techniques to retrieve timing differences between simultaneous recordings at ocean-bottom instruments after deployment has ended. Both techniques are based on the analysis of the cross correlation of ambient seismic noise and are effective even if clock drift is nonlinear. The first, called time symmetry analysis, is easy to apply but requires a proper illumination so that the noise cross-correlation functions are symmetric in time. The second is based on the doublet analysis method and does not have this restriction. Advantages and drawbacks of both approaches are discussed. Application to two OBS data sets shows that both can achieve synchronization of recordings down to about five milliseconds (a few percent of the main period used).},
	issn = {0037-1106},
	doi = {10.1785/0120130157},
	url = {https://doi.org/10.1785/0120130157},
	author = {Gou{\'e}dard, Pierre and Seher, Tim and McGuire, Jeffrey J. and Collins, John A. and van der Hilst, Robert D.}
}
@article {eakin_crustal-scale_2014,
	title = {Crustal-scale seismic profiles across the Manila subduction zone: The transition from intraoceanic subduction to incipient collision},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {119},
	number = {1},
	year = {2014},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/2013JB010395},
	pages = {1{\textendash}17},
	abstract = {AbstractWe use offshore multichannel seismic (MCS) reflection and wide-angle seismic data sets to model the velocity structure of the incipient arc-continent collision along two trench perpendicular transects in the Bashi Strait between Taiwan and Luzon. This area represents a transition from a tectonic regime dominated by subduction of oceanic crust of the South China Sea, west of the Philippines, to one dominated by subduction and eventual collision of rifted Chinese continental crust with the Luzon volcanic arc culminating in the Taiwan orogeny. The new seismic velocity models show evidence for extended to hyperextended continental crust, 10{\textendash}15 km thick, subducting along the Manila trench at 20.5{\textdegree}N along transect T1, as well as evidence indicating that this thinned continental crust is being structurally underplated to the accretionary prism at 21.5{\textdegree}N along transect T2, but not along T1 to the south. Coincident MCS reflection imaging shows highly stretched and faulted crust west of the trench along both transects and what appears to be a midcrustal detachment along transect T2, a potential zone of weakness that may be exploited by accretionary processes during subduction. An additional seismic reflection transect south of T1 shows subduction of normal ocean crust at the Manila trench.},
	keywords = {accretion, collision, rifted margin, subduction, Taiwan},
	issn = {2169-9356},
	doi = {10.1002/2013JB010395},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2013JB010395},
	author = {Eakin, Daniel H. and McIntosh, Kirk D. and Van Avendonk, H. J. A. and Lavier, Luc and Lester, Ryan and Liu, Char-Shine and Lee, Chao-Shing}
}
@article {van_avendonk_deep_2014,
	title = {Deep crustal structure of an arc-continent collision: Constraints from seismic traveltimes in central Taiwan and the Philippine Sea},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {119},
	number = {11},
	year = {2014},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/2014JB011327},
	pages = {8397{\textendash}8416},
	abstract = {The collision of continental crust of the Eurasian Plate with the overriding Luzon Arc in central Taiwan has led to compression, uplift, and exhumation of rocks that were originally part of the Chinese rifted margin. Though the kinematics of the fold-thrust belt on the west side of the orogen has been described in detail, the style of deformation in the lower crust beneath Taiwan is still not well understood. In addition, the fate of the Luzon Arc and Forearc in the collision is also not clear. Compressional wave arrival times from active-source and earthquake seismic data from the Taiwan Integrated Geodynamic Research program constrain the seismic velocity structure of the lithosphere along transect T5, an east-west corridor in central Taiwan. The results of our analysis indicate that the continental crust of the Eurasian margin forms a broad crustal root beneath central Taiwan, possibly with a thickness of 55 km. Compressional seismic velocities beneath the Central Range of Taiwan are as low as 5.5 km/s at 25 km depth, whereas P wave seismic velocities in the middle crust on the eastern flank of the Taiwan mountain belt average 6.5{\textendash}7.0 km/s. This suggests that the incoming sediments and upper crust of the Eurasian Plate are buried to midcrustal depth in the western flank of the orogen before they are exhumed in the Central Range. To the east, the Luzon Arc and Forearc are deformed beneath the Coastal Range of central Taiwan. Fragments of the rifted margin of the South China Sea that were accreted in the early stages of the collision form a new backstop that controls the exhumation of Eurasian strata to the west in this evolving mountain belt.},
	keywords = {arc-continent collision, earthquakes, Philippine Sea Plate, seismic refraction, Taiwan, tomography},
	issn = {2169-9356},
	doi = {10.1002/2014JB011327},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2014JB011327},
	author = {Van Avendonk, H. J. A. and Kuo-Chen, H. and McIntosh, K. D. and Lavier, L. L. and Okaya, D. A. and Wu, F. T. and Wang, C. Y. and Lee, C. S. and Liu, C. S.}
}
@article {froment_imaging_2014,
	title = {Imaging along-strike variations in mechanical properties of the Gofar transform fault, East Pacific Rise},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {119},
	number = {9},
	year = {2014},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/2014JB011270},
	pages = {7175{\textendash}7194},
	abstract = {AbstractA large part of global plate motion on mid-ocean ridge transform faults (RTFs) is not accommodated as major earthquakes. When large earthquakes do occur, they often repeat quasiperiodically. We focus here on the high slip rate (\~{}14 cm/yr) Gofar transform fault on the equatorial East Pacific Rise. This fault is subdivided into patches that slip during Mw 5.5{\textendash}6 earthquakes every 5 to 6 years. These patches are separated by rupture barriers that accommodate slip through swarms of smaller events and/or aseismic creep. We performed an imaging study to investigate which spatiotemporal variations of the fault zone properties control this segmentation in mechanical behavior and could explain the specific behavior of RTFs at the global scale. We adopt a double-difference approach in a joint inversion of active air gun shots and microseismicity recorded for 1 year. This data set includes the 2008 Mw 6 Gofar earthquake. The along-strike P wave velocity structure reveals an abrupt transition between the barrier area, characterized by a damaged fault zone of 10{\textendash}20\% reduced Vp and a nearly intact fault zone in the asperity area. The importance of the strength of the damage zone on the mechanical behavior is supported by the temporal S wave velocity changes which suggest increased damage within the barrier area, during the week preceding the Mw 6 earthquake. Our results support the conclusion that extended highly damaged zones are the key factor in limiting the role of major earthquakes to accommodate plate motion along RTFs.},
	keywords = {double-difference tomography, fault zone, imaging, mid-ocean ridge transform fault},
	issn = {2169-9356},
	doi = {10.1002/2014JB011270},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2014JB011270},
	author = {Froment, B. and McGuire, J. J. and van der Hilst, R. D. and Gou{\'e}dard, P. and Roland, E. C. and Zhang, H. and Collins, J. A.}
}
@article {collins_pn_2014,
	title = {Pn anisotropy beneath the South Island of New Zealand and implications for distributed deformation in continental lithosphere},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {119},
	number = {10},
	year = {2014},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/2014JB011233},
	pages = {7745{\textendash}7767},
	abstract = {Pn travel times from regional earthquakes recorded both by stations on New Zealand and by ocean bottom seismographs deployed offshore indicate anisotropy in the uppermost mantle beneath the region. The largest anisotropy of 8\% ({\textpm}2\%, 1σ) lies beneath the deforming part of the South Island to just off its West Coast, a zone roughly 100{\textendash}200 km wide. The fastest propagation is aligned N60{\textdegree}E ({\textpm}3{\textdegree}), essentially parallel to the largely strike-slip relative plate motion since 20 Ma, also N60{\textdegree}E. The magnitude of anisotropy decreases abruptly northwest and southeast of this zone, and on the southeast side of the island, the orientation of fastest propagation is between N32{\textdegree}W and N-S. The N60{\textdegree}E orientation of fast propagation is consistent with finite strain within the uppermost part of the mantle lithosphere if the measured 850 km of displacement of the Pacific plate past the Australia plate is spread over a region with a width of 100{\textendash}200 km. The agreement of this orientation of fast propagation with the orientation or relative plate motion suggests the possibility of but does not require some dynamic recrystallization in rock as cold as 500{\textendash}800{\textdegree}C, where Peierls creep seems to be the likely deformation mechanism. Such a strain distribution matches deformation of a thin viscous sheet that obeys a constitutive relationship of the form , where is the average strain rate and τ is the operative deviatoric stress, with an average value of n ≈ 3{\textendash}10. Presumably, the NW-SE fast propagation in the region southeast of the island results from strain that precedes the Cenozoic deformation that has shaped the island.},
	keywords = {anisotropy, Lithosphere, New Zealand, Pn},
	issn = {2169-9356},
	doi = {10.1002/2014JB011233},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2014JB011233},
	author = {Collins, John A. and Molnar, Peter}
}
@article {wolfson-schwehr_relationship_2014,
	title = {The relationship between seismicity and fault structure on the Discovery transform fault, East Pacific Rise},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {15},
	number = {9},
	year = {2014},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/2014GC005445},
	pages = {3698{\textendash}3712},
	abstract = {There is a global seismic moment deficit on mid-ocean ridge transform faults, and the largest earthquakes on these faults do not rupture the full fault area. We explore the influence of physical fault structure, including step-overs in the fault trace, on the seismic behavior of the Discovery transform fault, 4S on the East Pacific Rise. One year of microseismicity recorded during a 2008 ocean bottom seismograph deployment (24,377 0 ML 4.6 earthquakes) and 24 years of Mw 5.4 earthquakes obtained from the Global Centroid Moment Tensor catalog, are correlated with surface fault structure delineated from high-resolution multibeam bathymetry. Each of the 15 5.4 Mw 6.0 earthquakes that occurred on Discovery between 1 January 1990 and 1 April 2014 was relocated into one of five distinct rupture patches using a teleseismic surface wave cross-correlation technique. Microseismicity was relocated using the HypoDD relocation algorithm. The western fault segment of Discovery (DW) is composed of three zones of varying structure and seismic behavior: a zone with no large events and abundant microseismicity, a fully coupled zone with large earthquakes, and a complex zone with multiple fault strands and abundant seismicity. In general, microseismicity is reduced within the patches defined by the large, repeating earthquakes. While the extent of the large rupture patches on DW correlates with physical features in the bathymetry, step-overs in the primary fault trace are not observed at patch boundaries, suggesting along-strike heterogeneity in fault zone properties controls the size and location of the large events.},
	keywords = {earthquakes, East Pacific Rise, fault structure, transform fault},
	issn = {1525-2027},
	doi = {10.1002/2014GC005445},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2014GC005445},
	author = {Wolfson-Schwehr, Monica and Boettcher, Margaret S. and McGuire, Jeffrey J. and Collins, John A.}
}
@article {zietlow_upper_2014,
	title = {Upper mantle seismic anisotropy at a strike-slip boundary: South Island, New Zealand},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {119},
	number = {2},
	year = {2014},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/2013JB010676},
	pages = {1020{\textendash}1040},
	abstract = {New shear wave splitting measurements made from stations onshore and offshore the South Island of New Zealand show a zone of anisotropy 100{\textendash}200 km wide. Measurements in central South Island and up to approximately 100 km offshore from the west coast yield orientations of the fast quasi-shear wave nearly parallel to relative plate motion, with increased obliquity to this orientation observed farther from shore. On the eastern side of the island, fast orientations rotate counterclockwise to become nearly perpendicular to the orientation of relative plate motion approximately 200 km off the east coast. Uniform delay times between the fast and slow quasi-shear waves of nearly 2.0 s onshore continue to stations approximately 100 km off the west coast, after which they decrease to 1 s at 200 km. Stations more than 300 km from the west coast show little to no splitting. East coast stations have delay times around 1 s. Simple strain fields calculated from a thin viscous sheet model (representing distributed lithospheric deformation) with strain rates decreasing exponentially to both the northwest and southeast with e-folding dimensions of 25{\textendash}35 km (approximately 75\% of the deformation within a zone 100{\textendash}140 km wide) match orientations and amounts of observed splitting. A model of deformation localized in the lithosphere and then spreading out in the asthenosphere also yields predictions consistent with observed splitting if, at depths of 100{\textendash}130 km below the lithosphere, typical grain sizes are 6{\textendash}7 mm.},
	keywords = {mantle lithosphere, MOANA, New Zealand, ocean bottom seismometers, seismic anisotropy, South Island},
	issn = {2169-9356},
	doi = {10.1002/2013JB010676},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2013JB010676},
	author = {Zietlow, Daniel W. and Sheehan, Anne F. and Molnar, Peter H. and Savage, Martha K. and Hirth, Greg and Collins, John A. and Hager, Bradford H.}
}
@article {dunn_crustal_2013,
	title = {Crustal construction and magma chamber properties along the Eastern Lau Spreading Center},
	journal = {Earth and Planetary Science Letters},
	volume = {371-372},
	year = {2013},
	month = {jun},
	pages = {112{\textendash}124},
	abstract = {The L-SCAN active-source seismic tomography experiment maps the crustal structure and magmatic system along a 120-km-long section of the back-arc Eastern Lau Spreading Center (ELSC), where the ridge undergoes abrupt changes in morphology and composition associated with increasing proximity to the Tofua volcanic arc. Using this dataset, we picked \textasciitilde197,000 P-wave travel times from 57 seismic airgun lines recorded at 83 ocean bottom seismograph stations, and inverted for a 3-D P-wave velocity image. The seismic images reveal a prominent, but narrow, seismic low velocity volume (LVV) located beneath all surveyed ridge segments, consistent with the high temperatures and melt of a crustal magmatic system. Crustal magmatic systems thus underlie spreading axes even where previous seismic reflection surveys did not detect magma lens reflectors, accounting for the heat source of high-temperature hydrothermal vents in these areas. The top of the LVV closely follows the ridge axis and steps across three overlapping spreading centers. As the offset of the overlap increases, the LVV becomes increasingly discontinuous across the ridge limbs. Surprisingly, the LVV is as much as twice as wide, but deeper, in the northern part of the ridge system where the crust is thinner, as compared to the LVV beneath the southern segments, where the crust is relatively thicker. The width of the LVV may be modulated by the degree of deep hydrothermal activity or temporal variations in melt supply, and thus may not correlate directly with the average melt flux as indicated by crustal thickness. Over the past 4Myr, the location of the ridge has swept across different mantle compositional domains, and the crust produced at the ridge formed a zoned pattern. The interpretation is that thick, highly porous, volcanic layers with felsic compositions cap regions of thick crust; thinner volcanic layers of basaltic composition cap regions of thinner crust. The zonal pattern indicates that the influence of slab-derived water on crustal construction has substantially decreased over time.},
	keywords = {back-arc basin, Eastern Lau Spreading Center, magma chamber, mantle melting, mid-ocean ridge, seismic tomography},
	issn = {0012-821X},
	doi = {10.1016/j.epsl.2013.04.008},
	url = {https://www.sciencedirect.com/science/article/pii/S0012821X13001891},
	author = {Dunn, Robert A. and Martinez, Fernando and Conder, James A.}
}
@article {stephen_deep_2013,
	title = {Deep seafloor arrivals in long range ocean acoustic propagation},
	journal = {The Journal of the Acoustical Society of America},
	volume = {134},
	number = {4},
	year = {2013},
	note = {Publisher: Acoustical Society of America},
	month = {oct},
	pages = {3307{\textendash}3317},
	abstract = {Ocean bottom seismometer observations at 5000 m depth during the long-range ocean acoustic propagation experiment in the North Pacific in 2004 show robust, coherent, late arrivals that are not readily explained by ocean acoustic propagation models. These {\textquotedblleft}deep seafloor{\textquotedblright} arrivals are the largest amplitude arrivals on the vertical particle velocity channel for ranges from 500 to 3200 km. The travel times for six (of 16 observed) deep seafloor arrivals correspond to the sea surface reflection of an out-of-plane diffraction from a seamount that protrudes to about 4100 m depth and is about 18 km from the receivers. This out-of-plane bottom-diffracted surface-reflected energy is observed on the deep vertical line array about 35 dB below the peak amplitude arrivals and was previously misinterpreted as in-plane bottom-reflected surface-reflected energy. The structure of these arrivals from 500 to 3200 km range is remarkably robust. The bottom-diffracted surface-reflected mechanism provides a means for acoustic signals and noise from distant sources to appear with significant strength on the deep seafloor.},
	issn = {0001-4966},
	doi = {10.1121/1.4818845},
	url = {https://asa.scitation.org/doi/full/10.1121/1.4818845},
	author = {Stephen, Ralph A. and Thompson Bolmer, S. and Udovydchenkov, Ilya A. and Worcester, Peter F. and Dzieciuch, Matthew A. and Andrew, Rex K. and Mercer, James A. and Colosi, John A. and Howe, Bruce M.}
}
@article {mcintosh_inversion_2013,
	title = {Inversion of a hyper-extended rifted margin in the southern Central Range of Taiwan},
	journal = {Geology},
	volume = {41},
	number = {8},
	year = {2013},
	month = {aug},
	pages = {871{\textendash}874},
	abstract = {Seismic reflection and wide-angle data acquired across, south, and west of Taiwan show that extended to hyper-extended continental crust of the Chinese continental margin is present more than 200 km south of the shelf and is subducting at the Manila Trench. Furthermore, crustal-scale tomographic velocity models show that this crust is underthrusted to \~{}15 km depth below the accretionary prism, where it then is structurally underplated to the base of the prism. We document an increasing volume of accreted crust from south to north, and in our northern transect high-velocity material of the accretionary prism can be directly linked to outcrops of Central Range basement rocks. In map view the Central Range of Taiwan is clearly contiguous with the Hengchun Peninsula and Hengchun submarine ridge to the south. Accordingly, we propose a new model in which the Central Range forms directly from the accretionary prism, including the basement core, which originates from subducted, and then accreted, extended to hyper-extended continental crust.},
	issn = {0091-7613},
	doi = {10.1130/G34402.1},
	url = {https://doi.org/10.1130/G34402.1},
	author = {McIntosh, Kirk and van Avendonk, Harm and Lavier, Luc and Lester, W. Ryan and Eakin, Daniel and Wu, Francis and Liu, Char-Shine and Lee, Chao-Shing}
}
@article {mcguire_millimeter-level_2013,
	title = {Millimeter-level precision in a seafloor geodesy experiment at the Discovery transform fault, East Pacific Rise},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {14},
	number = {10},
	year = {2013},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/ggge.20225},
	pages = {4392{\textendash}4402},
	abstract = {Direct-path acoustic ranging is a promising seafloor geodetic technique for continuous high-resolution monitoring of geodynamical process such as fault slip and magma intrusion. Here we report on a yearlong acoustic ranging experiment conducted across the discovery transform fault at \~{}4{\textdegree}S on the East Pacific Rise. The ranging instruments utilized a novel acoustic signal designed to enhance precision. We find that, after correcting for variations in sound speed at the path end-points, the ranging measurements have a precision of \~{}1 mm over baselines approaching 1 km in length. The primary difficulty in this particular experiment was with the physical stability of the benchmarks, which were deployed free fall from a ship. Despite the stability issues, it appears that the portion of the transform fault that the array covered was locked during the year of our survey. The primary obstacle to continuous, high sample rate, high-precision geodetic monitoring of oceanic ridges and transform faults is now limited to the construction of geodetic monuments that are well anchored into bedrock.},
	keywords = {oceanic transform fault, seafloor geodesy},
	issn = {1525-2027},
	doi = {10.1002/ggge.20225},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/ggge.20225},
	author = {McGuire, Jeffrey J. and Collins, John A.}
}
@article {worcester_north_2013,
	title = {The North Pacific Acoustic Laboratory deep-water acoustic propagation experiments in the Philippine Sea},
	journal = {The Journal of the Acoustical Society of America},
	volume = {134},
	number = {4},
	year = {2013},
	note = {Publisher: Acoustical Society of America},
	month = {oct},
	pages = {3359{\textendash}3375},
	abstract = {A series of experiments conducted in the Philippine Sea during 2009{\textendash}2011 investigated deep-water acoustic propagation and ambient noise in this oceanographically and geologically complex region: (i) the 2009 North Pacific Acoustic Laboratory (NPAL) Pilot Study/Engineering Test, (ii) the 2010{\textendash}2011 NPAL Philippine Sea Experiment, and (iii) the Ocean Bottom Seismometer Augmentation of the 2010{\textendash}2011 NPAL Philippine Sea Experiment. The experimental goals included (a) understanding the impacts of fronts, eddies, and internal tides on acoustic propagation, (b) determining whether acoustic methods, together with other measurements and ocean modeling, can yield estimates of the time-evolving ocean state useful for making improved acoustic predictions, (c) improving our understanding of the physics of scattering by internal waves and spice, (d) characterizing the depth dependence and temporal variability of ambient noise, and (e) understanding the relationship between the acoustic field in the water column and the seismic field in the seafloor. In these experiments, moored and ship-suspended low-frequency acoustic sources transmitted to a newly developed distributed vertical line array receiver capable of spanning the water column in the deep ocean. The acoustic transmissions and ambient noise were also recorded by a towed hydrophone array, by acoustic Seagliders, and by ocean bottom seismometers.},
	issn = {0001-4966},
	doi = {10.1121/1.4818887},
	url = {https://asa.scitation.org/doi/full/10.1121/1.4818887},
	author = {Worcester, Peter F. and Dzieciuch, Matthew A. and Mercer, James A. and Andrew, Rex K. and Dushaw, Brian D. and Baggeroer, Arthur B. and Heaney, Kevin D. and D{\textquoteright}Spain, Gerald L. and Colosi, John A. and Stephen, Ralph A. and Kemp, John N. and Howe, Bruce M. and Van Uffelen, Lora J. and Wage, Kathleen E.}
}
@article {roland_seismic_2012,
	title = {Seismic velocity constraints on the material properties that control earthquake behavior at the Quebrada-Discovery-Gofar transform faults, East Pacific Rise},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {117},
	number = {B11},
	year = {2012},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2012JB009422},
	abstract = {Mid-ocean ridge transform faults (RTFs) vary strongly along strike in their ability to generate large earthquakes. This general observation suggests that local variations in material properties along RTFs exert a primary control on earthquake rupture dynamics. We explore these relationships by examining the seismic structure of two RTFs that have distinctly different seismic coupling. We determine the seismic velocity structure at the Gofar and Quebrada faults on the East Pacific Rise (EPR) using P wave traveltime tomography with data from two active-source wide-angle refraction lines crossing the faults. We image low-velocity zones (LVZs) at both faults, where P wave velocities are reduced by as much as 0.5{\textendash}1.0 km/s (\~{}10{\textendash}20\%) within a several kilometer wide region. At the Gofar fault, the LVZ extends through the entire crust, into the seismogenic zone. We rule out widespread serpentinization as an explanation for the low velocities, owing to the lack of a corresponding signal in the locally measured gravity field. The reduced velocities can be explained if the plate boundary region is composed of fault material with enhanced fluid-filled porosity (1.5{\textendash}8\%). Local seismic observations indicate that the high-porosity region lies within a \~{}10 km long portion of the fault that fails in large swarms of microearthquakes and acts as a barrier to the propagation of large (M \~{} 6.0) earthquakes. Tomographic images of fault structure combined with observed earthquake behavior suggest that EPR transform segments capable of generating large earthquakes have relatively intact gabbro within the seismogenic zone, whereas segments that slip aseismically or via earthquake swarms are composed of highly fractured, >=2 km wide damage zones that extend throughout the crust.},
	keywords = {fault structure, marine seismology, rupture dynamics, tomography, transform fault},
	issn = {2156-2202},
	doi = {10.1029/2012JB009422},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2012JB009422},
	author = {Roland, Emily and Lizarralde, Dan and McGuire, Jeffrey J. and Collins, John A.}
}
@article {collins_seismicity_2012,
	title = {Seismicity of the Atlantis Massif detachment fault, 30{\textdegree}N at the Mid-Atlantic Ridge},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {13},
	number = {10},
	year = {2012},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2012GC004210},
	abstract = {At the oceanic core complex that forms the Atlantis Massif at 30{\textdegree}N on the Mid-Atlantic Ridge, slip along the detachment fault for the last 1.5{\textendash}2 Ma has brought lower crust and mantle rocks to the seafloor. Hydroacoustic data collected between 1999 and 2003 suggest that seismicity occurred near the top of the Massif, mostly on the southeastern section, while detected seismicity along the adjacent ridge axis was sparse. In 2005, five short-period ocean bottom seismographs (OBS) were deployed on and around the Massif as a pilot experiment to help constrain the distribution of seismicity in this region. Analysis of six months of OBS data indicates that, in contrast to the results of the earlier hydroacoustic study, the vast majority of the seismicity is located within the axial valley. During the OBS deployment, and within the array, seismicity was primarily composed of a relatively constant background rate and two large aftershock sequences that included 5 teleseismic events with magnitudes between 4.0 and 4.5. The aftershock sequences were located on the western side of the axial valley adjacent to the Atlantis Massif and close to the ridge-transform intersection. They follow Omori{\textquoteright}s law, and constitute more than half of the detected earthquakes. The OBS data also indicate a low but persistent level of seismicity associated with active faulting within the Atlantis Massif in the same region as the hydroacoustically detected seismicity. Within the Massif, the data indicate a north-south striking normal fault, and a left-lateral, strike-slip fault near a prominent, transform-parallel, north-facing scarp. Both features could be explained by changes in the stress field at the inside corner associated with weak coupling on the Atlantis transform. Alternatively, the normal faulting within the Massif might indicate deformation of the detachment surface as it rolls over to near horizontal from an initial dip of about 60{\textdegree} beneath the axis, and the strike-slip events may indicate transform-parallel movement on adjacent detachment surfaces.},
	keywords = {Atlantis Massif, hydroacoustic, Mid-Atlantic Ridge, oceanic detachment fault, seismicity, T-phase},
	issn = {1525-2027},
	doi = {10.1029/2012GC004210},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2012GC004210},
	author = {Collins, John A. and Smith, Deborah K. and McGuire, Jeffrey J.}
}
@article {mcguire_variations_2012,
	title = {Variations in earthquake rupture properties along the Gofar transform fault, East Pacific Rise},
	journal = {Nature Geoscience},
	volume = {5},
	number = {5},
	year = {2012},
	note = {Number: 5 Publisher: Nature Publishing Group},
	month = {may},
	pages = {336{\textendash}341},
	abstract = {Mid-ocean ridge transform faults experience more foreshocks than continental faults, yet the mainshock rarely ruptures the entire fault. Analysis of seismic data from the Gofar transform fault at the East Pacific Rise indicates that the foreshock region has different material properties from the mainshock region, and acts as a barrier to rupture propagation.},
	keywords = {seismology},
	issn = {1752-0908},
	doi = {10.1038/ngeo1454},
	url = {https://www.nature.com/articles/ngeo1454},
	author = {McGuire, Jeffrey J. and Collins, John A. and Gou{\'e}dard, Pierre and Roland, Emily and Lizarralde, Dan and Boettcher, Margaret S. and Behn, Mark D. and van der Hilst, Robert D.}
}
@article {laske_asymmetric_2011,
	title = {Asymmetric shallow mantle structure beneath the Hawaiian Swell-evidence from Rayleigh waves recorded by the PLUME network},
	journal = {Geophysical Journal International},
	volume = {187},
	number = {3},
	year = {2011},
	pages = {1725{\textendash}1742},
	abstract = {We present models of the 3-D shear velocity structure of the lithosphere and asthenosphere beneath the Hawaiian hotspot and surrounding region. The models are derived from long-period Rayleigh-wave phase velocities that were obtained from the analysis of seismic recordings collected during two year-long deployments for the Hawaiian Plume-Lithosphere Undersea Mantle Experiment. For this experiment, broad-band seismic sensors were deployed at nearly 70 seafloor sites as well as 10 sites on the Hawaiian Islands. Our seismic images result from a two-step inversion of path-averaged dispersion curves using the two-station method. The images reveal an asymmetry in shear velocity structure with respect to the island chain, most notably in the lower lithosphere at depths of 60 km and greater, and in the asthenosphere. An elongated, 100-km-wide and 300-km-long low-velocity anomaly reaches to depths of at least 140 km. At depths of 60 km and shallower, the lowest velocities are found near the northern end of the island of Hawaii. No major velocity anomalies are found to the south or southeast of Hawaii, at any depth. The low-velocity anomaly in the asthenosphere is consistent with an excess temperature of 200-250 {\textdegree}C and partial melt at the level of a few percent by volume, if we assume that compositional variations as a result of melt extraction play a minor role. We also image small-scale low-velocity anomalies within the lithosphere that may be associated with the volcanic fields surrounding the Hawaiian Islands.},
	issn = {0956-540X},
	doi = {10.1111/j.1365-246X.2011.05238.x},
	url = {https://doi.org/10.1111/j.1365-246X.2011.05238.x},
	author = {Laske, Gabi and Markee, Amanda and Orcutt, John A. and Wolfe, Cecily J. and Collins, John A. and Solomon, Sean C. and Detrick, Robert S. and Bercovici, David and Hauri, Erik H.}
}
@article {dunn_contrasting_2011,
	title = {Contrasting crustal production and rapid mantle transitions beneath back-arc ridges},
	journal = {Nature},
	volume = {469},
	number = {7329},
	year = {2011},
	note = {Number: 7329 Publisher: Nature Publishing Group},
	pages = {198{\textendash}202},
	abstract = {The Eastern Lau spreading centre, located on the Lau back-arc basin hydrothermal vent system between Fiji and Tonga, is a focus site of the Ridge 2000 research programme of the US National Science Foundation. The first large-scale seismic study of the area reveals large and abrupt across- and along-strike changes in crustal properties, implying correspondingly large discontinuities in the nature of the mantle supplying melt to the ridge axes. The authors conclude that stable, broad triangular upwelling regions, as inferred for mid-ocean ridges, cannot form near the mantle wedge corner. Instead, the observations imply a dynamic process in which the ridge upwelling zone preferentially captures water-rich low-viscosity mantle when it is near the arc. As the ridge moves away from the arc, a tipping point is reached at which the material is rapidly released, resulting in rapid changes in the character of the crust formed at the ridge.},
	keywords = {seismology},
	issn = {1476-4687},
	doi = {10.1038/nature09690},
	url = {https://www.nature.com/articles/nature09690},
	author = {Dunn, Robert A. and Martinez, Fernando}
}
@article {yao_structure_2011,
	title = {Structure of young East Pacific Rise lithosphere from ambient noise correlation analysis of fundamental- and higher-mode Scholte-Rayleigh waves},
	journal = {Nouveaux d{\'e}veloppements de l{\textquoteright}imagerie et du suivi temporel {\`a} partir du bruit sismique},
	volume = {343},
	number = {8},
	year = {2011},
	month = {sep},
	pages = {571{\textendash}583},
	abstract = {Inter-station Green{\textquoteright}s functions estimated from ambient noise studies have been widely used to investigate crustal structure. However, most studies are restricted to continental areas and use fundamental-mode surface waves only. In this study, we recover inter-station surface (Scholte-Rayleigh) wave empirical Green{\textquoteright}s function (EGFs) of both the fundamental- and the first-higher mode using one year of continuous seismic noise records on the vertical component from 28 ocean bottom seismographs deployed in the Quebrada/Discovery/Gofar transform faults region on the East Pacific Rise. The average phase-velocity dispersion of the fundamental mode (period band 2{\textendash}30s) and the first-higher mode (period band 3{\textendash}7s) from all EGFs are used to invert for the 1-D average, shear-velocity structure in the crust and uppermost mantle using a model-space search algorithm. The preferred shear-velocity models reveal low velocities (4.29km/s) between Moho and 25km depth below sea-surface, suggesting the absence of a fast uppermost mantle lid in this young (0{\textendash}2Myr) oceanic region. An even more pronounced low-velocity zone, with shear velocities \~{}3.85km/s, appears at a depth between 25{\textendash}40km below sea-surface. Along with previous results, our study indicates that the shear velocity in the uppermost oceanic mantle increases with increasing seafloor age, consistent with age-related lithospheric cooling. R{\'e}sum{\'e} Les fonctions de Green estim{\'e}es {\`a} partir de l{\textquoteright}analyse du bruit ambiant ont beaucoup {\'e}t{\'e} utilis{\'e}es pour {\'e}tudier la structure de la cro{\^u}te terrestre. La plupart de ces travaux sont toutefois limit{\'e}s aux zones continentales, et ne consid{\`e}rent que le mode fondamental des ondes de surface. Dans cette {\'e}tude, les fonctions de Green empiriques (EGFs) du mode fondamental et du premier mode sup{\'e}rieur des ondes de surface (Scholte-Rayleigh) sont reconstruites {\`a} partir d{\textquoteright}une ann{\'e}e d{\textquoteright}enregistrements continus de la composante verticale du bruit sismique sur 28 ocean bottom seismometers (OBSs) d{\'e}ploy{\'e}s dans la r{\'e}gion des failles transformantes Quebrada/Discovery/Gofar, le long de la dorsale oc{\'e}anique du Pacifique Est. La dispersion moyenne des vitesses de phase du mode fondamental (dans la bande de p{\'e}riode 2{\textendash}30s) et du premier mode sup{\'e}rieur (dans la bande 3{\textendash}7s), issus des EGFs, est utilis{\'e}e pour d{\'e}terminer un mod{\`e}le moyen 1D de la vitesse des ondes de cisaillement dans la cro{\^u}te et le manteau sup{\'e}rieur {\`a} partir d{\textquoteright}un algorithme de recherche dans l{\textquoteright}espace mod{\`e}le. Le mod{\`e}le de vitesse des ondes de cisaillement r{\'e}sultant pr{\'e}sente une couche de faible vitesse (4,29km/s) entre le Moho et 25km sous le niveau de la mer, ce qui sugg{\`e}re l{\textquoteright}absence de couche superficielle rapide dans le manteau sup{\'e}rieur de cette jeune r{\'e}gion oc{\'e}anique (0{\textendash}2millions d{\textquoteright}ann{\'e}es). Une zone de faible vitesse encore plus prononc{\'e}e, avec une vitesse de cisaillement de \~{}3,85km/s, appara{\^\i}t entre 25 et 40km sous le niveau de la mer. Combin{\'e}e avec des r{\'e}sultats ant{\'e}rieurs, notre {\'e}tude montre que la vitesse de cisaillement dans le manteau oc{\'e}anique sup{\'e}rieur augmente avec l{\textquoteright}{\^a}ge du fond oc{\'e}anique, ce qui est en accord avec le refroidissement dans le temps de la lithosph{\`e}re.},
	keywords = {ambient noise, Bruit ambiant, Dorsale Est Pacifique, East Pacific Rise, Fundamental- and higher-mode Scholte-Rayleigh waves, Lithosphere, Low-velocity zone, Manteau oc{\'e}anique sup{\'e}rieur, Modes fondamental et sup{\'e}rieur des ondes de Scholte-Rayleigh, Oceanic Uppermost Mantle, Zone de faible vitesse},
	issn = {1631-0713},
	doi = {10.1016/j.crte.2011.04.004},
	url = {https://www.sciencedirect.com/science/article/pii/S1631071311000952},
	author = {Yao, Huajian and Gou{\'e}dard, Pierre and Collins, John A. and McGuire, Jeffrey J. and van der Hilst, Robert D.}
}
@article {stephen_deep_2009,
	title = {Deep seafloor arrivals: An unexplained set of arrivals in long-range ocean acoustic propagation},
	journal = {The Journal of the Acoustical Society of America},
	volume = {126},
	number = {2},
	year = {2009},
	note = {Publisher: Acoustical Society of America},
	month = {aug},
	pages = {599{\textendash}606},
	abstract = {Receptions, from a ship-suspended source (in the band 50{\textendash}100Hz 50 {\textendash} 100 Hz ) to an ocean bottom seismometer (about 5000m 5000 m depth) and the deepest element on a vertical hydrophone array (about 750m 750 m above the seafloor) that were acquired on the 2004 Long-Range Ocean Acoustic Propagation Experiment in the North Pacific Ocean, are described. The ranges varied from 50to3200km 50 to 3200 km . In addition to predicted ocean acoustic arrivals and deep shadow zone arrivals (leaking below turning points), {\textquotedblleft}deep seafloor arrivals,{\textquotedblright} that are dominant on the seafloor geophone but are absent or very weak on the hydrophone array, are observed. These deep seafloor arrivals are an unexplained set of arrivals in ocean acoustics possibly associated with seafloor interface waves.},
	issn = {0001-4966},
	doi = {10.1121/1.3158826},
	url = {https://asa.scitation.org/doi/full/10.1121/1.3158826},
	author = {Stephen, Ralph A. and Bolmer, S. Thompson and Dzieciuch, Matthew A. and Worcester, Peter F. and Andrew, Rex K. and Buck, Linda J. and Mercer, James A. and Colosi, John A. and Howe, Bruce M.}
}
@article {miller_upper_2009,
	title = {Upper mantle structure beneath the Caribbean-South American plate boundary from surface wave tomography},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {114},
	number = {B1},
	year = {2009},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2007JB005507},
	abstract = {We have measured shear wave velocity structure of the crust and upper mantle of the Caribbean-South American boundary region by analysis of fundamental mode Rayleigh waves in the 20- to 100-s period band recorded at the BOLIVAR/GEODINOS stations from 2003 to 2005. The model shows lateral variations that primarily correspond to tectonic provinces and boundaries. A clear linear velocity change parallels the plate bounding dextral strike-slip fault system along the northern coast of Venezuela, illustrating the differences between the South American continental lithosphere, the Venezuelan archipelago, and the Caribbean oceanic lithosphere. At depths up to 120 km beneath the Venezuelan Andes and the Maracaibo block, there is evidence of underthrusting of the Caribbean plate, but there is no other evidence of subduction of the Caribbean plate beneath the South American plate. In eastern Venezuela, linear crustal low velocities are associated with the fold and thrust belts whereas as higher crustal velocities are imaged in the Guayana shield lithosphere. The subducting oceanic part of the South American plate is imaged beneath the Antilles arc. The surface wave images combined with seismicity data suggest shear tearing of the oceanic lithosphere away from the buoyant continental South American plate offshore of northeastern Venezuela. The continental lithosphere south of the slab tear is bent down toward the plate boundary in response to the propagating tear in the lithosphere. We interpret a nearly vertical low-velocity {\textquotedblleft}column{\textquotedblright} west of the tear centered beneath the Cariaco Basin, with three-dimensional asthenospheric flow around the southern edge of the subducting oceanic lithosphere, with the asthenosphere escaping from beneath continental South America and rising into the plate boundary zone. The complex plate boundary structure is best examined in three dimensions. We discuss the new surface wave tomographic inversion in the context of results from other researchers including local seismicity, teleseismic shear wave splits, and interpretations from active source profiling.},
	keywords = {plate boundary, surface wave tomography, upper mantle structure},
	issn = {2156-2202},
	doi = {10.1029/2007JB005507},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2007JB005507},
	author = {Miller, Meghan S. and Levander, Alan and Niu, Fenglin and Li, Aibing}
}
@article {clark_characterizing_2008,
	title = {Characterizing the Caribbean{\textendash}South American plate boundary at 64{\textdegree}W using wide-angle seismic data},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {113},
	number = {B7},
	year = {2008},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2007JB005329},
	abstract = {We present wide-angle velocity modeling results from profile 64{\textdegree}W of the Broadband Ocean-Land Investigation of Venezuela and the Antilles arc Region (BOLIVAR) project. Line 64W is a 460-km-long, approximately north-south, onshore-offshore reflection/refraction transect located approximately at 64{\textdegree}W longitude. The profile extends across the transform plate boundary between the southeastern Caribbean (CAR) and South American (SA) plates. East of the profile the plate boundary bends to the north, and SA subducts beneath CAR. We utilize first-arrival tomography to resolve a smooth velocity field for the sediments and upper/middle crust and then use a layered approach to resolve a sharp velocity contrast for the Moho, simultaneously inverting refracted Pn and reflected PmP arrivals. We image crustal and upper mantle structure across the plate boundary zone. We interpret that the strike-slip system that accommodates relative motion between CAR and SA extends near vertically through the entire crust and offsets the Moho. We see no evidence supporting a major component of convergence, and rather than a wide boundary zone of overlapping lithospheric plates, we interpret the plate boundary to be confined to the 33-km-wide, near-vertical strike-slip system. Previously interpreted thrust faults flanking the strike-slip system appear to be confined to the upper/middle crust and may be related to the detachment of subducting South American lithosphere at the southern terminus of the Lesser Antilles subduction zone east of 64{\textdegree}W.},
	keywords = {El Pilar, velocity modeling, Venezuela margin},
	issn = {2156-2202},
	doi = {10.1029/2007JB005329},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2007JB005329},
	author = {Clark, S. A. and Zelt, C. A. and Magnani, M. B. and Levander, A.}
}
@article {christeson_crustal_2008,
	title = {Crustal structure of the Caribbean{\textendash}northeastern South America arc-continent collision zone},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {113},
	number = {B8},
	year = {2008},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2007JB005373},
	abstract = {We present the results of a 568-km-long regional wide-angle seismic profile conducted in the southeastern Caribbean that crosses an active island arc, a remnant arc, two basins possibly floored by oceanic crust, an allochthonous terrane of forearc affinity, and the passive margin of northern South America. The velocity structures of the Late Cretaceous Aves Ridge remnant arc and Miocene and younger Lesser Antilles arc are remarkably similar, which implies that magmatic processes have remained moderately steady over time. Crustal thickness is \~{}26 km at the Aves Ridge and \~{}24 km at the Lesser Antilles arc. In comparison to the Izu-Bonin and Aleutian arcs, the Lesser Antilles arc is thinner and has no evidence for a lower crustal cumulate layer, which is consistent with the estimated low magma production rates of the Lesser Antilles arc. Crustal thickness beneath the Grenada and Tobago basins is 4{\textendash}10 km, and the velocity structure suggests that these basins could be floored by oceanic crust. A decrease of \~{}1 km/s in average seismic velocity of the upper crust is observed from NW to SE across the North Coast fault zone; we argue that this marks the suture between the far-traveled Caribbean arc and the passive margin of the South American continent. Current strike-slip motion between the Caribbean and South American plates is located \~{}30 km to the south, and thus material originally deposited on the South American passive margin has now been transferred to the Caribbean plate.},
	keywords = {arc-continent collision, Lesser Antilles, SE Caribbean},
	issn = {2156-2202},
	doi = {10.1029/2007JB005373},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2007JB005373},
	author = {Christeson, Gail L. and Mann, Paul and Escalona, Alejandro and Aitken, Trevor J.}
}
@article {clark_identification_2008,
	title = {Identification and tectonic implications of a tear in the South American plate at the southern end of the Lesser Antilles},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {9},
	number = {11},
	year = {2008},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2008GC002084},
	abstract = {In the southeast corner of the Caribbean, westward subduction of (Atlantic) oceanic South America beneath the Lesser Antilles transitions to east-west transform motion between continental South America and the Caribbean plate. This geometry requires negatively buoyant, subducting, oceanic South American lithosphere to progressively detach from positively buoyant, continental South American lithosphere. The most widely accepted model is slab break-off, with oblique arc-continent collision and northwest dipping, continental subduction precipitating narrow rifting in the subducting slab. In contrast, the subduction-transform edge propagator (STEP) model conceptualizes progressive detachment along a vertical, dip-slip tear through the lithosphere, with stress focused at the edge of the propagating transform boundary. We present four types of seismic data to resolve the ongoing lithospheric detachment: local seismicity, receiver functions, wide-angle seismic velocity inversion, and a regional, balanced cross section constrained by petroleum industry data. These four data sets image a near-vertical tear extending through the entire lithosphere, revealing a key mechanism for the structural evolution of Venezuela.},
	keywords = {jelly sandwich, lithospheric detachment, mantle dynamics, slab break-off, STEP, tear},
	issn = {1525-2027},
	doi = {10.1029/2008GC002084},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2008GC002084},
	author = {Clark, S. A. and Sobiesiak, M. and Zelt, C. A. and Magnani, M. B. and Miller, M. S. and Bezada, M. J. and Levander, A.}
}
@article {clark_negligible_2008,
	title = {Negligible convergence and lithospheric tearing along the Caribbean{\textendash}South American plate boundary at 64{\textdegree}W},
	journal = {Tectonics},
	volume = {27},
	number = {6},
	year = {2008},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2008TC002328},
	abstract = {Prior studies of the Caribbean{\textendash}South American plate boundary have suffered from poor constraint on the structure of the crust and uppermost mantle. We use a recent wide-angle velocity model from the Broadband Ocean-Land Investigation of Venezuela and the Antilles arc Region project to constrain new seismic reflection data and previously published line drawing interpretations of the Caribbean{\textendash}South American plate boundary at 64{\textdegree}W. Though commonly characterized as obliquely convergent, we determine that convergence is negligible in our study area. Previous estimates of Miocene to present north-south shortening onshore eastern Venezuela have commonly been 115 km or higher, but we constrain shortening to \~{}35 km onshore, with an additional \~{}30 km offshore. With such minor convergence, we conclude that uplift and basin subsidence in eastern Venezuela does not derive from typical collisional orogeny. Instead, the largely vertical tectonics likely result from mantle dynamics associated with an eastward propagating, near-vertical tear in the lithosphere along the former passive margin.},
	keywords = {El Pilar fault, Serrania del Interior, STEP fault},
	issn = {1944-9194},
	doi = {10.1029/2008TC002328},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2008TC002328},
	author = {Clark, S. A. and Levander, A. and Magnani, M. B. and Zelt, C. A.}
}
