@article {anderson_deformation_2025,
	title = {Deformation on Rainbow Massif, Mid-Atlantic Ridge, Illuminated With Microearthquakes Detected by Machine Learning},
	journal = {Geophysical Research Letters},
	volume = {52},
	number = {2},
	year = {2025},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2024GL111285},
	pages = {e2024GL111285},
	abstract = {Abstract Oceanic detachment fault systems are characteristic of slow-spreading mid-ocean ridges, where reduced magma supply leads to increased extension by faulting and exhumation of oceanic core complexes (OCCs). OCCs have complicated structure reflecting the interplay between magmatic, hydrothermal, and tectonic processes. We use microearthquake data from a 9-month ocean bottom seismometer deployment to image deformation structures in the Rainbow massif on the Mid-Atlantic Ridge. Using a machine-learning enabled workflow to obtain an earthquake catalog containing > {\vphantom} > \textbackslash68,000 events, we find seismicity occurred in distinct clusters that correlate with previously imaged velocity anomalies and dipping subsurface reflections. Our results are consistent with a dipping alteration front within the massif overlying late-stage intrusions and suggest a transpressional fault accommodates a non-transform offset north of the massif. Our results demonstrate OCCs continue to deform in a complex way after a detachment fault has been abandoned due to combined effects of tectonic stresses, magmatism, and alteration.},
	keywords = {detachment faults, machine learning, microearthquakes, oceanic core complex, slow spreading mid-ocean ridges},
	doi = {https://doi.org/10.1029/2024GL111285},
	author = {Anderson, Evan C. and Parnell-Turner, Ross and Sohn, Robert A. and Fan, Wenyuan}
}
@article {ashraf_high-resolution_2025,
	title = {A High-Resolution 3-D P-Wave Velocity Structure of the South-Central Cascadia Subduction Zone From Wide-Angle Shore-Crossing Seismic Refraction Data},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {130},
	number = {2},
	year = {2025},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2024JB029525},
	pages = {e2024JB029525},
	abstract = {Abstract This study addresses a significant gap in understanding the features of the south-central Cascadia subduction zone, a region characterized by complex geologic, tectonic, and seismic transitions both offshore and onshore. Unlike other segments along this margin, this area lacks a 3-D velocity model to delineate its structural and geological features on a fine scale. To address this void, we developed a high-resolution 3-D P-wave velocity model using active source seismic data from ship-borne seismic shots recorded on temporary and permanent onshore seismic stations and ocean-bottom seismometers. Our model shows velocity variations across the region with distinct velocity-depth profiles for the Siletz, Franciscan, and Klamath terranes in the overlying plate. We identified seaward dipping high-velocity static backstops associated with the Siletz and Klamath terranes, situated near the shoreline and further inland, respectively. Regions of reduced crustal velocity are associated with crustal faults. Moreover, there is significant along-strike depth variation in the subducting slab, which is about 4 km deeper near the thick, dense Siletz terrane and becomes shallower near the predominantly less-dense Franciscan terrane. This highlights a sudden tectonic and geologic transition at the southern boundary of the Siletz terrane. Our velocity model also indicates slightly increased hydration, though still minimal, in both the oceanic crust and the upper mantle of the subducting plate compared to other parts of the margin.},
	doi = {https://doi.org/10.1029/2024JB029525},
	author = {Ashraf, Asif and Hooft, Emilie E. E. and Toomey, Douglas R. and Tr{\'e}hu, Anne M. and Nolan, Sarah and Wirth, Erin A. and Ward, Kevin M.}
}
@article {kim_application_2024,
	title = {Application of the reverberation waveform inversion for the high-resolution sediment layer structure in the Pacific},
	journal = {Geophysical Journal International},
	volume = {240},
	number = {2},
	year = {2024},
	note = {_eprint: https://academic.oup.com/gji/article-pdf/240/2/1331/61230955/ggae444.pdf},
	pages = {1331{\textendash}1344},
	abstract = {This study presents the velocity structures of the seafloor sediment across the Pacific using teleseismic body waves recorded by arrays of ocean bottom seismometers (OBSs). We apply the method inverting the multicomponent stacked autocorrelation functions and radial-component waveform of teleseismic body waves. We analyze OBSs distributed across the Pacific Ocean, through a wide range of water depths and equipped with various sensor types. The inverted models agreeing with measurements of seafloor drilling samples demonstrate the broad applicability of employing the inversion method to resolve sediment thicknesses ranging from \&lt;100 m to a few kilometers. In addition to various broad-band OBSs, we confirm our method works also for short-period sensors, since our retrieved the model using data from a short-period sensor in Northeast Japan agrees with active-source seismic survey analyses. The constrained models show various numbers of intrasediment discontinuities across different locations. Furthermore, the newly characterized sediment models have higher values of P-wave to S-wave velocity ratio ({{V}_P}\textbackslash/{{V}_S}\textbackslash) than the previously known scaling relationships, which suggests a larger effect of sediment-layer reverberation on the body-wave analysis than we have anticipated. The sediment velocity models obtained in this study produce Rayleigh-wave admittances that are consistent with those in previous studies but with much finer structural details within the sediment layer. The reverberation waveform inversion method will enable improved predictions of the impact of the water and sediment layers in body-wave records from existing and future OBS observations.},
	issn = {1365-246X},
	doi = {10.1093/gji/ggae444},
	url = {https://doi.org/10.1093/gji/ggae444},
	author = {Kim, HyeJeong and Kawakatsu, Hitoshi and Akuhara, Takeshi and Takeuchi, Nozomu and Isse, Takehi and Shiobara, Hajime and Sugioka, Hiroko and Utada, Hisashi and Kim, YoungHee and Lee, Sang-Mook}
}
@article {atkins_hydroacoustic_2024,
	title = {Hydroacoustic Evidence for Offshore Lava Emplacement During the 2018 Kilauea Eruption},
	journal = {Geophysical Research Letters},
	volume = {51},
	number = {20},
	year = {2024},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2024GL110885},
	month = {10/2024},
	pages = {e2024GL110885},
	abstract = {During the 2018 Kilauea eruption, over half the erupted lava was deposited on the seafloor. Lava flows crossing the shoreline generated sounds that were recorded by a network of hydrophones. We show that short-duration, broadband signals associated with lava-water interactions occurred throughout the eruption but increased in number when the Ahalanui ocean entry initiated on July 11. These terminated in early August coincident with the eruption{\textquoteright}s end. We compare hydroacoustic data with transmission loss models and eruption photographs to show that coastal explosive activity was poorly recorded by the hydrophone network. Similarly, strong hydroacoustic signals did not correlate with observed activity. These results suggest that acoustic signals were generated by lava flowing up to 100 s of meters offshore. Offshore lava flows can be hazardous to boaters, but hydrophones provide a means by which these hazards can be detected.},
	keywords = {hydrophone, hydrovolcanic, Kilauea, lava-water interaction},
	issn = {1944-8007},
	doi = {10.1029/2024GL110885},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2024GL110885},
	author = {Atkins, C. and Costa, O. and Caplan-Auerbach, J.}
}
@article {cones_offshore_2024,
	title = {Offshore windfarm construction elevates metabolic rate and increases predation vulnerability of a key marine invertebrate},
	journal = {Environmental Pollution},
	volume = {360},
	year = {2024},
	month = {11/2024},
	pages = {124709},
	abstract = {A global increase in offshore windfarm development is critical to our renewable energy future. Yet, widespread construction plans have generated substantial concern for impacts to co-occurring organisms and the communities they form. Pile driving construction, prominent in offshore windfarm development, produces among the highest amplitude sounds in the ocean creating widespread concern for a diverse array of taxa. However, studies addressing ecologically key species are generally lacking and most research is disparate, failing to integrate across response types (e.g., behavior, physiology, and ecological interactions), particularly in situ. The lack of integrative field studies presents major challenges to understand or mitigate actual impacts of offshore wind development. Here, we examined critical behavioral, physiological, and antipredator impacts of actual pile driving construction on the giant sea scallop (Placopecten magellanicus). Benthic taxa including bivalves are of particular concern because they are sound-sensitive, cannot move appreciable distances away from the stressor, and support livelihoods as one of the world{\textquoteright}s most economically and socially important fisheries. Overall, pile driving sound impacted scallops across a series of behavioral and physiological assays. Sound-exposed scallops consistently reduced their valve opening (22\%), resulting in lowered mantle water oxygen levels available to the gills. Repeated and rapid valve adductions led to a 56\% increase in metabolic rates relative to pre-exposure baselines. Consequently, in response to predator stimuli, sound-exposed scallops displayed a suite of significantly weaker antipredator behaviors including fewer swimming events and shorter time-to-exhaustion. These results show aquatic construction activities can induce metabolic and ecologically relevant changes in a key benthic animal. As offshore windfarm construction accelerates globally, our field-based study highlights that spatial overlap with benthic taxa may cause substantial metabolic changes, alter important fisheries resources, and ultimately could lead to increased predation.},
	keywords = {Metabolism, noise, Predation, Scallop, Sound pollution},
	issn = {0269-7491},
	doi = {10.1016/j.envpol.2024.124709},
	url = {https://www.sciencedirect.com/science/article/pii/S0269749124014234},
	author = {Cones, Seth F. and J{\'e}z{\'e}quel, Youenn and Jarriel, Sierra and Aoki, Nad{\`e}ge and Brewer, Hannah and Collins, John and Chauvaud, Laurent and Mooney, T. Aran}
}
@article {adimah_shear-wave_2024,
	title = {Shear-wave velocity structure of the Blanco oceanic transform fault zone},
	journal = {Geophysical Journal International},
	volume = {239},
	number = {2},
	year = {2024},
	month = {11/2024},
	pages = {1287{\textendash}1312},
	abstract = {Oceanic transform faults (OTFs) facilitate hydrothermal circulation which can modify the fault zone materials and affect their rheological evolution. However, the depth extent and variability of fluid infiltration, degree of mineral alteration and their relationship with earthquake behaviour has only been characterized along a few OTFs globally. Here, we use first-overtone Rayleigh waves extracted from seismic ambient noise to estimate the shear-wave velocity structure beneath the Blanco Transform Fault Zone (BTFZ). Compared to the adjoining normal oceanic plates, relatively variable and slow velocities reduced by at least \$\textbackslashsim\$0.2{\textendash}0.4~km s-1 (\$\textbackslashsim\$4{\textendash}8 per cent) are observed from the crust down to \$\textbackslashsim\$22~km depth along some segments of the BTFZ. The crustal slow velocities can be explained by enhanced fluid-filled porosity of \$\textbackslashsim\$0.4{\textendash}10.9 per cent caused by intense fracturing associated with abundant seismicity. Slow uppermost mantle velocities are predominantly consistent with \$\textbackslashsim\$1.2{\textendash}37 per cent serpentinization and \$\textbackslashsim\$9 per cent hydration, indicating variable and deep fluid infiltration that exceeds 15~km depth. For instance, shear-wave velocities (\$\textbackslashsim\$4.3{\textendash}4.4~km s-1) in the uppermost mantle beneath the Blanco Ridge suggest extensive serpentinization (\$\textbackslashsim\$13{\textendash}25 per cent), which might explain the recently documented earthquake swarms linked with aseismic creep. In comparison, within the vicinity of the ridge-transform intersections at depths \$\textbackslashsim\$\$\textbackslashgt \$16~km, low velocities (\$\textbackslashsim\$4.1{\textendash}4.2~km s-1) that are consistent with the presence of up to \$\textbackslashsim\$1.6 per cent partial melt suggest intratransform magmatism which would contradict the long-held simple conservative strike-slip characterization of OTFs.},
	issn = {1365-246X},
	doi = {10.1093/gji/ggae318},
	url = {https://doi.org/10.1093/gji/ggae318},
	author = {Adimah, Nicholas Irabor and Tan, Yen Joe and Russell, Joshua Berryman}
}
@article {acquisto_structural_2024,
	title = {Structural Controls on Megathrust Slip Behavior Inferred From a 3D, Crustal-Scale, P-Wave Velocity Model of the Alaska Peninsula Subduction Zone},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {129},
	number = {11},
	year = {2024},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2024JB029632},
	pages = {e2024JB029632},
	abstract = {Abstract In subduction zones, along-strike and downdip variations in megathrust slip behavior are linked to changes in properties of the subducting and overriding plates. Although marine geophysical methods provide insights into subduction zone structures, most surveys consist of sparse 2D profiles, limiting our understanding of first-order controls. Here, we use active-source seismic data to derive a 3D crustal-scale P-wave velocity model of the Alaska Peninsula subduction zone that encompasses both plates and spans the Semidi segment and SW Kodiak asperity. Our results reveal modest variations within the incoming plate, attributed to a series of fracture zones, seamounts and their associated basement swell, collectively contributing to plate hydration. Basement swell appears to modulate the distribution and type of sediment entering the trench, likely impacting observed variations in slip behavior. The overriding plate exhibits significant heterogeneity. The updip limit and width of the dynamic backstop are similar between the SW Kodiak asperity and eastern Semidi segment, but differ significantly from the Western Semidi segment. These distinctions likely account for differences in earthquake rupture patterns and interseismic coupling among these segments. Additionally, high-velocities in the mid-lower forearc crust coincide with the location of megathrust slip during the Mw 8.2 2021 Chignik event. We interpret these velocities as intracrustal intrusions that contributed to the deep rupture of the 2021 event. Our findings suggest that the contrasting structural and material properties of both the incoming and overriding plates influence the spatially complex and semi-persistent segmentation of the megathrust offshore the Alaska Peninsula.},
	doi = {https://doi.org/10.1029/2024JB029632},
	author = {Acquisto, T. and B{\'e}cel, A. and Canales, J. P. and Beauc{\'e}, E.}
}
@article {carbotte_subducting_2024,
	title = {Subducting plate structure and megathrust morphology from deep seismic imaging linked to earthquake rupture segmentation at Cascadia},
	journal = {Science Advances},
	volume = {10},
	number = {23},
	year = {2024},
	note = {_eprint: https://www.science.org/doi/pdf/10.1126/sciadv.adl3198},
	pages = {eadl3198},
	abstract = {The origin of rupture segmentation along subduction zone megathrusts and linkages to the structural evolution of the subduction zone are poorly understood. Here, regional-scale seismic imaging of the Cascadia margin is used to characterize the megathrust spanning 900 km from Vancouver Island to the California border, across the seismogenic zone to a few tens of kilometers from the coast. Discrete domains in lower plate geometry and sediment underthrusting are identified, not evident in prior regional plate models, which align with changes in lithology and structure of the upper plate and interpreted paleo-rupture patches. Strike-slip faults in the lower plate associated with oblique subduction mark boundaries between regions of distinct lower plate geometry. Their formation may be linked to changes in upper plate structure across long-lived upper plate faults. The Juan de Fuca plate is fragmenting within the seismogenic zone at Cascadia as the young plate bends beneath the heterogeneous upper plate resulting in structural domains that coincide with paleo-rupture segmentation. A fragmented lower plate in the Cascadia seismogenic zone bounds structural domains linked to paleo-rupture segmentation.},
	doi = {10.1126/sciadv.adl3198},
	author = {Carbotte, Suzanne M. and Boston, Brian and Han, Shuoshuo and Shuck, Brandon and Beeson, Jeffrey and Canales, J. Pablo and Tobin, Harold and Miller, Nathan and Nedimovic, Mladen and Tr{\'e}hu, Anne and Lee, Michelle and Lucas, Madelaine and Jian, Hanchao and Jiang, Danqi and Moser, Liam and Anderson, Chris and Judd, Darren and Fernandez, Jaime and Campbell, Chuck and Goswami, Antara and Gahlawat, Rajendra}
}
@article {zhang_water-wave-induced_2024,
	title = {Water-Wave-Induced OBS Noise: Theories, Observations, and Potential Applications},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {129},
	number = {4},
	year = {2024},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2023JB027787},
	month = {04/2024},
	pages = {e2023JB027787},
	abstract = {The horizontal records of ocean-bottom seismometers (OBS) are usually highly noisy, generally due to ocean-bottom currents tilting the instrument, which greatly limits their practical usage in ocean-bottom seismology. In shallow water, water waves with energy concentration around 0.07 Hz induce additional noise on OBSs. Such noise is not well understood. In this article, we propose a noise model to explain the horizontal noise around 0.07 Hz. The noise model consists of three types of noise, that is, water-wave-induced noise, current noise with a relatively constant orientation, and background random noise. The wave-induced horizontal acceleration is theoretically shown to be proportional to the time derivative of ocean-bottom pressure. We validate the noise model and related theories using realistic observations. Results are potentially applicable to determine the propagation direction of water waves nearshore, and also provide constraints on the underlying Earth structure. The results can also be applied to the removal of wave-induced noise, achieving a typical maximum improvement in the signal-to-noise ratio of 10{\textendash}20 dB for time periods with strong wave noise.},
	keywords = {infragravity waves, OBS noise, ocean-bottom pressure, tilt noise},
	issn = {2169-9356},
	doi = {10.1029/2023JB027787},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023JB027787},
	author = {Zhang, Chun and An, Chao}
}
@article {schlaphorst_local_2023,
	title = {Local seismicity around the Chain Transform Fault at the Mid-Atlantic Ridge from OBS observations},
	journal = {Geophysical Journal International},
	volume = {234},
	number = {2},
	year = {2023},
	note = {Publisher: Oxford University Press (OUP)},
	month = {08/2023},
	pages = {1111{\textendash}1124},
	abstract = {Seismicity along transform faults provides important constraints for our understanding of the factors that control earthquake ruptures. Oceanic transform faults are particularly informative due to their relatively simple structure in comparison to their continental counterparts. The seismicity of several fast-moving transform faults has been investigated by local networks, but as of today there been few studies of transform faults in slow spreading ridges. Here, we present the first local seismicity catalogue based on event data recorded by a temporary broad-band network of 39 ocean{\textendash}bottom seismometers located around the slow-moving Chain Transform Fault (CTF) along the Mid-Atlantic Ridge (MAR) from 2016 to 2017 March. We locate 972 events in the area by simultaneously inverting for a 1-D velocity model informed by the event P- and S-arrival times. We refine the depths and focal mechanisms of the larger events using deviatoric moment tensor inversion. Most of the earthquakes are located along the CTF (700) and Romanche transform fault (94) and the MAR (155); a smaller number (23) can be observed on the continuing fracture zones or in intraplate locations. The ridge events are characterized by normal faulting and most of the transform events are characterized by strike-slip faulting, but with several reverse mechanisms that are likely related to transpressional stresses in the region. CTF events range in magnitude from 1.1 to 5.6 with a magnitude of completeness around 2.3. Along the CTF we calculate a b-value of 0.81 {\textpm} 0.09. The event depths are mostly shallower than 15 km below sea level (523), but a small number of high-quality earthquakes (16) are located deeper, with some (8) located deeper than the brittle-ductile transition as predicted by the 600 {\textdegree}C-isotherm from a simple thermal model. The deeper events could be explained by the control of sea water infiltration on the brittle failure limit.},
	keywords = {3706 Geophysics},
	issn = {0956-540X},
	doi = {10.1093/gji/ggad124},
	author = {Schlaphorst, David and Rychert, Catherine A. and Harmon, Nicholas and Hicks, Stephen P. and Bogiatzis, Petros and Kendall, J-Michael and Abercrombie, Rachel E.}
}
@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 {fang_smatstack_2023,
	title = {SMatStack to Enhance Noisy Teleseismic Seismic Phases: Validation and Application to Resolving Depths of Oceanic Transform Earthquakes},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {24},
	number = {11},
	year = {2023},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2023GC011109},
	month = {10/2023},
	pages = {e2023GC011109},
	abstract = {The depths of most moderate-sized oceanic earthquakes are poorly constrained because of the lack of local recording stations and noisy teleseismic recordings. This hampers our understanding of slip behaviors along oceanic faults and the mechanical properties of the oceanic lithosphere. In this study, we develop a new method to enhance the weak body-wave signals, particularly the depth phases, associated with earthquakes on oceanic transform faults using large-aperture arrays in the teleseismic range. We simulate the enhanced teleseismic signals to refine the centroid depths of moderate-sized earthquakes. We validate the new approach using synthetic waveforms and show it outperforms conventional methods when dealing with noisy signals. We obtain the depth estimates for three moderate-sized earthquakes on the Chain transform fault in the equatorial Atlantic Ocean and find two of them are consistent with a local catalog derived using oceanic bottom seismometers. Application of the new method to the past decades of teleseismic recordings of moderate-sized earthquakes on the large and slow-slipping transform faults will provide significantly improved constraints on the width of the seismogenic zone, thus advancing our understanding of the rheology of oceanic lithosphere and earthquake processes in oceanic settings and, by comparison, their more dangerous continental counterparts. The new method is not limited to oceanic transform earthquakes, but can be easily adapted to other seismological studies in which noisy but coherent signals could be revisited for better usage.},
	keywords = {array analysis, earthquake depths, oceanic transform faults, seismogenic zone},
	issn = {1525-2027},
	doi = {10.1029/2023GC011109},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023GC011109},
	author = {Fang, Hongjian and Abercrombie, Rachel E.}
}
@article {ruppert_enhanced_2022,
	title = {Enhanced Regional Earthquake Catalog with Alaska Amphibious Community Seismic Experiment Data},
	journal = {Seismological Research Letters},
	volume = {94},
	number = {1},
	year = {2022},
	pages = {522{\textendash}530},
	abstract = {The Alaska Amphibious Community Seismic Experiment (AACSE) comprised 75 ocean-bottom seismometers and 30 land stations and covered about 650~km along the segment of the subduction zone that includes Kodiak Island, the Alaska Peninsula and the Shumagin Islands between May 2018 and September 2019. This unprecedented onshore-offshore dataset provided an opportunity to compile a greatly enhanced earthquake catalog for the region by both increasing the number of detected earthquakes and improving the accuracy of their source parameters. We use all available regional and AACSE campaign seismic data to compile an earthquake catalog for the region between Kodiak and the Shumagin Islands including the Alaska Peninsula (51{\textdegree}~N{\textendash}59{\textdegree}~N, 148{\textdegree}~W{\textendash}163{\textdegree}~W). We apply the same processing and reporting standards to additional picks and events as the Alaska Earthquake Center currently uses for compilation of the authoritative regional earthquake catalog. Over 7200 events (both newly detected and previously reported) have been processed with AACSE data. We added about 30\% more events, 60\% more phase picks, lowered the magnitude of completeness by about 0.2 on average across the region, and improved location errors. All data have been published in public data archives. In addition, we test the machine-learning earthquake detection and picking algorithm EarthquakeTransformer (EQT) on the AACSE seismic dataset, comparing EQT-determined P and S picks with the new catalog. EQT is entirely trained on land data, whereas AACSE is amphibious. Overall, EQT finds 59\% of P and 63\% of S arrivals in the catalog within 300~km epicentral distance. The percent of catalog picks detected by EQT varies inversely with earthquake epicentral distance, and EQT performs particularly poorly on data from earthquakes recorded by instruments in the outer rise.},
	issn = {0895-0695},
	doi = {10.1785/0220220226},
	url = {https://doi.org/10.1785/0220220226},
	author = {Ruppert, Natalia A. and Barcheck, Grace and Abers, Geoffrey A.}
}
@article {acquisto_evidence_2022,
	title = {Evidence of Strong Upper Oceanic Crustal Hydration Outboard the Alaskan and Sumatran Subduction Zones},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {127},
	number = {10},
	year = {2022},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2022JB024751},
	pages = {e2022JB024751},
	abstract = {The hydration state of subducting oceanic crust has been proposed to influence subduction zone processes like seismic coupling at the megathrust interface and arc magmatism downdip. Plate bending in the outer rise region is thought to help rehydrate the incoming oceanic lithosphere before subduction. Although numerous seismic refraction studies provide constraints on the amount of water stored in the lower crust and uppermost mantle, little information exists about how much free water is present in the upper 1{\textendash}2 km of oceanic crust. Here, we present results from the application of advanced techniques to long-offset multi-channel seismic data acquired outboard the Alaskan and South Sumatran subduction zones. Our results show that the incoming upper crustal seismic layer, layer 2A, is significantly hydrated in both areas. Favorable conditions offshore the Alaska Peninsula promote the creation of a dense system of bending-related faults, facilitating the infiltration of fluids that increases average water estimates to \~{}3.9 wt.\% H2O in the outer rise. As the crust subducts and temperature increases, some free water may react with the host rocks to form mineral-bound water that is carried to greater depths, in agreement with elevated water contents found in arc lavas of Shumagin Gap volcanoes. Offshore Sumatra, we propose that similar layer 2A water estimates (\~{}3.2 wt.\% H2O average) and heterogeneous hydration within 2B are associated with the ongoing, slow, complex deformation occurring in the Wharton Basin and thus potentially contribute to the presence of a long-lived slow slip event recently inferred there at seismogenic depths.},
	keywords = {Alaska, hydration, subduction zone, Sumatra, upper crust},
	issn = {2169-9356},
	doi = {10.1029/2022JB024751},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022JB024751},
	author = {Acquisto, Tanner and B{\'e}cel, Anne and Singh, Satish C. and Carton, H{\'e}l{\`e}ne}
}
@conference {schmidt-aursch_noise_2022,
	title = {Noise characteristics of ocean-bottom seismometer data in the Bransfield Strait, Antarctica},
	booktitle = {EPIC348. Sitzung der AG Seismologie, M{\"u}nster, 2022-09-26-2022-09-29},
	year = {2022},
	month = {sep},
	address = {M{\"u}nster},
	abstract = {All seismological data contain not only desired source signals, but also noise. There are various natural and artificial noise sources like wind, waves, traffic, industry, etc. Data recorded by ocean-bottom seismometers (OBS) show a different content of noise than onshore data; mainly because the OBS are located directly in one of the major noise generators: the oceans. Oceanic microseisms dominate the recordings over a broad frequency band, and there are several noise sources not known onshore, e.g. marine mammals, ship traffic, marine seismic surveys and especially in the polar regions sea ice and icebergs. In the framework of the BRAVOSEIS project, eight broadband ocean-bottom seismometers were deployed for one year in the Bransfield Strait, Antarctica. The ambient noise was helpful to correct the clock drift of the data loggers by means of noise cross-correlations. High-resolution probabilistic power spectral densities and spectrograms were calculated for all stations and channels to study the noise-generating processes. An analysis of tidal signals were performed for various time series including temperature recordings. Although all OBS were located within the same basin, they differ significantly in their noise characteristics. The noise spectrum was divided into several frequency bands. Some bands show seasonal variations, others are persistent during the entire year. A few noise signatures are coherent between all OBS, this is typical for origins far away. Most noise sources occur very locally and are specific for each OBS depending on parameters like water depth or the abundance of deep water currents. Generally, the noise properties are complex and show a great variation in time and space.},
	url = {https://epic.awi.de/id/eprint/57417/},
	author = {Schmidt-Aursch, Mechita C. and Almendros, Javier and Geissler, Wolfram and Wilcock, William}
}
@article {deng_theoretical_2022,
	title = {Theoretical Solution and Applications of Ocean Bottom Pressure Induced by Seismic Waves at High Frequencies},
	journal = {Geophysical Research Letters},
	volume = {49},
	number = {9},
	year = {2022},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2021GL096952},
	pages = {e2021GL096952},
	abstract = {Previous studies have demonstrated that the ocean-bottom pressure associated with seismic seafloor motion is linearly proportional to the vertical seafloor acceleration, for frequencies much lower than the resonance frequency of water layer (c0/4h, c0 water sound speed, h water depth). In this article, we use realistic observations to verify a theoretical relation between the ocean-bottom pressure and vertical acceleration up to the water resonance frequency. We then show two applications of the theoretical relation. First, the pressure amplitude recorded by differential pressure gauges is calibrated, and the calibration coefficient is found to vary by frequency. Second, Rayleigh wave phase velocity near the water resonance frequency can be calculated from recordings of pressure and vertical seafloor acceleration at a single station, which is useful to constrain the shallow Earth structure.},
	issn = {1944-8007},
	doi = {10.1029/2021GL096952},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021GL096952},
	author = {Deng, Han and An, Chao and Cai, Chen and Ren, Hengxin}
}
@article {cabieces_upper-lithospheric_2022,
	title = {Upper-lithospheric structure of northeastern Venezuela from joint inversion of surface-wave dispersion and receiver functions},
	journal = {Solid Earth},
	volume = {13},
	number = {11},
	year = {2022},
	note = {Publisher: Copernicus GmbH},
	month = {11/2022},
	pages = {1781{\textendash}1801},
	abstract = {We use 1.5 years of continuous recordings from an amphibious seismic network deployment in the region of northeastern South America and the southeastern Caribbean to study the crustal and uppermost mantle structure through a joint inversion of surface-wave dispersion curves determined from ambient seismic noise and receiver functions. The availability of both ocean bottom seismometers (OBSs) and land stations makes this experiment ideal to determine the best processing methods to extract reliable empirical Green{\textquoteright}s functions (EGFs) and construct a 3D shear velocity model. Results show EGFs with high signal-to-noise ratio for land{\textendash}land, land{\textendash}OBS and OBS{\textendash}OBS paths from a variety of stacking methods. Using the EGF estimates, we measure phase and group velocity dispersion curves for Rayleigh and Love waves. We complement these observations with receiver functions, which allow us to perform an H-k analysis to obtain Moho depth estimates across the study area. The measured dispersion curves and receiver functions are used in a Bayesian joint inversion to retrieve a series of 1D shear-wave velocity models, which are then interpolated to build a 3D model of the region. Our results display clear contrasts in the oceanic region across the border of the San Sebastian{\textendash}El Pilar strike-slip fault system as well as a high-velocity region that corresponds well with the continental craton of southeastern Venezuela. We resolve known geological features in our new model, including the Espino Graben and the Guiana Shield provinces, and provide new information about their crustal structures. Furthermore, we image the difference in the crust beneath the Matur{\'\i}n and Gu{\'a}rico sub-basins.},
	issn = {1869-9510},
	doi = {10.5194/se-13-1781-2022},
	url = {https://se.copernicus.org/articles/13/1781/2022/},
	author = {Cabieces, Roberto and Arnaiz-Rodr{\'\i}guez, Mariano S. and Villase{\~n}or, Antonio and Berg, Elizabeth and Olivar-Casta{\~n}o, Andr{\'e}s and Ventosa, Sergi and Ferreira, Ana M. G.}
}
@article {gosselin_azimuthal_2021,
	title = {Azimuthal anisotropy in Bayesian surface wave tomography: application to northern Cascadia and Haida Gwaii, British Columbia},
	journal = {Geophysical Journal International},
	volume = {224},
	number = {3},
	year = {2021},
	month = {mar},
	pages = {1724{\textendash}1741},
	abstract = {Surface wave tomography is a valuable tool for constraining azimuthal anisotropy at regional scales. However, sparse and uneven coverage of dispersion measurements make meaningful uncertainty estimation challenging, especially when applying subjective model regularization. This paper considers azimuthal anisotropy constrained by measurements of surface wave dispersion data within a Bayesian trans-dimensional (trans-d) tomographic inversion. A recently proposed alternative model parametrization for trans-d inversion is implemented in order to produce more realistic models than previous studies considering trans-d surface wave tomography. The reversible-jump Markov chain Monte Carlo sampling technique is used to numerically estimate the posterior probability density of the model parameters. Isotropic and azimuthally anisotropic components of surface wave group velocity maps (and their associated uncertainties) are estimated while avoiding model regularization and allowing model complexity to be determined by the data information content. Furthermore, data errors are treated as unknown, and solved for within the inversion. The inversion method is applied to measurements of surface wave dispersion from regional earthquakes recorded over northern Cascadia and Haida Gwaii, a region of complex active tectonics but highly heterogeneous station coverage. Results for isotropic group velocity are consistent with previous studies that considered the southern part of the study region over Cascadia. Azimuthal anisotropic fast-axis directions are generally margin-parallel between Vancouver Island and Haida Gwaii, with a small change in direction and magnitude along the margin which may be attributed to the changing tectonic regime (from subduction to transform tectonics). Estimated errors on the dispersion data (solved for within the inversion) reveal a correlation between surface wave period and the dependence of data errors on travel path length. This paper demonstrates the value of considering azimuthal anisotropy within Bayesian tomographic inversions. Furthermore, this work provides structural context for future studies of tectonic structure and dynamics of northern Cascadia and Haida Gwaii, with the aim of improving our understanding of seismic and tsunami hazards.},
	issn = {0956-540X},
	doi = {10.1093/gji/ggaa561},
	url = {https://doi.org/10.1093/gji/ggaa561},
	author = {Gosselin, Jeremy M and Audet, Pascal and Schaeffer, Andrew J and Darbyshire, Fiona A and Est{\`e}ve, Cl{\'e}ment}
}
@article {an_characteristics_2021,
	title = {Characteristics of Low-Frequency Horizontal Noise of Ocean-Bottom Seismic Data},
	journal = {Seismological Research Letters},
	volume = {93},
	number = {1},
	year = {2021},
	pages = {257{\textendash}267},
	abstract = {Horizontal records of ocean-bottom seismographs are usually noisy at low frequencies (\&lt; 0.1~Hz). The noise source is believed to be associated with ocean-bottom currents that may tilt the instrument. Currently horizontal records are mainly used to remove the coherent noise in vertical records, and there has been little literature that quantitatively discusses the mechanism and characteristics of low-frequency horizontal noise. In this article, we analyze in situ ocean-bottom measurements by rotating the data horizontally and evaluating the coherency between different channels. Results suggest that the horizontal noise consists of two components, random noise and principle noise whose direction barely changes in time. The amplitude and the direction of the latter are possibly related to the intensity and direction of ocean-bottom currents. Rotating the horizontal records to the direction of the principle noise can largely suppress the principle noise in the orthogonal horizontal channel. In addition, the horizontal noise is incoherent with pressure, indicating that the noise source is not ocean surface water waves (infragravity waves). At some stations in shallow waters (\&lt;300~m), horizontal noise around 0.07~Hz is found to be linearly proportional to the temporal derivative of pressure, which is explained by forces of added mass due to infragravity waves.},
	issn = {0895-0695},
	doi = {10.1785/0220200349},
	url = {https://doi.org/10.1785/0220200349},
	author = {An, Chao and Cai, Chen and Zhou, Lei and Yang, Ting}
}
@article {rychert_dynamic_2021,
	title = {A dynamic lithosphere{\textendash}asthenosphere boundary near the equatorial Mid-Atlantic Ridge},
	journal = {Earth and Planetary Science Letters},
	volume = {566},
	year = {2021},
	month = {07/2021},
	pages = {116949},
	abstract = {In plate tectonic theory a weak asthenosphere is required to facilitate the motions of the rigid plates. Partial melt could weaken the mantle, in turn impacting convection, but to date the existence of persistent melt has remained controversial. A wide range of scenarios has been reported in terms of the location, amount and pathways of melt. Here we use data collected by 39 ocean bottom seismometers deployed near the equatorial Mid-Atlantic Ridge on 0 to 80 Myr old seafloor. We calculate S-to-P (Sp) receiver functions and perform waveform modeling. We jointly interpret with shear-wave velocity tomography from surface waves and magnetotelluric (MT) imaging to take advantage of a range of resolutions and sensitivities and illuminate the structure of the oceanic lithosphere and the underlying asthenosphere. We image a tectonic plate thickness that increases with age in one location but undulates in another location. We infer thin and slightly thicker melt channels and punctuated regions of ascending partial melt several hundred kilometers off the ridge axis. This suggests melt persists over geologic timescales, although its character is dynamic, with implications for the lithosphere{\textendash}asthenosphere boundary (LAB) and the driving forces of the plates. Ascending melt intermittently feeds melt channels at the base of the plate. The associated melt-enhanced buoyancy increases the influence of ridge-push in driving plate motions, whereas the channelized melt reduces the resistance of the plates to motion. Therefore, melt dynamics may play a larger role in controlling plate tectonics than previously thought.},
	keywords = {melt dynamics, Mid-Atlantic Ridge, oceanic lithosphere{\textendash}asthenosphere boundary, Plate tectonics, receiver functions, seismology},
	issn = {0012-821X},
	doi = {10.1016/j.epsl.2021.116949},
	url = {https://www.sciencedirect.com/science/article/pii/S0012821X21002089},
	author = {Rychert, Catherine A. and Tharimena, Saikiran and Harmon, Nicholas and Wang, Shunguo and Constable, Steven and Kendall, J. Michael and Bogiatzis, Petros and Agius, Matthew R. and Schlaphorst, David}
}
@article {nakai_near_2021,
	title = {Near Trench 3D Seismic Attenuation Offshore Northern Hikurangi Subduction Margin, North Island, New Zealand},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {126},
	number = {3},
	year = {2021},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2020JB020810},
	month = {02/2021},
	pages = {e2020JB020810},
	abstract = {We image seismic attenuation near the Hikurangi trench offshore New Zealand, using ocean bottom and land-based seismometers, revealing high attenuation above a recurring shallow slow-slip event and within the subducting Hikurangi Plateau. The Hikurangi subduction margin east of the North Island, New Zealand is the site of frequent shallow slow slip events. Overpressured fluids are hypothesized to lead to slow slip at shallow depths close to the oceanic trench. Seismic attenuation, energy loss of seismic waves, can be used to detect high temperatures, melt, the presence of fluids, and fractures. We use local earthquake P- and S-waves from 180 earthquakes to invert for t*, and subsequently invert for Qp and Qs, offshore the North Island directly above the area of slow slip. We image Qp and Qs to \~{}25 km depth, increasing resolution of previously identified coastal low Q (100{\textendash}300), and finding a new region of even higher attenuation (Qp and Qs < 50{\textendash}100) directly above the shallow slow slip event of 2014{\textendash}2015, beneath the offshore seismic array. This highest attenuation is downdip of a subducting seamount, and is spatially correlated with a high seismic reflectivity zone and Vp/Vs > 1.85, all of which provide evidence for the presence of fluids. The Qp and Qs is low at the trench (<50{\textendash}100) and in the subducting plate (100{\textendash}200), suggesting that seismic wave scattering due to faults, fractures, and the inherent heterogeneous composition of the Hikurangi Plateau, a large igneous province, plays a role in seismic attenuation.},
	keywords = {fluids, seismic attenuation, subduction zone},
	issn = {2169-9356},
	doi = {10.1029/2020JB020810},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020JB020810},
	author = {Nakai, Jenny S. and Sheehan, Anne F. and Abercrombie, Rachel E. and Eberhart-Phillips, Donna}
}
@article {alongi_probing_2021,
	title = {Probing the Southern Cascadia Plate Interface With the Dense Amphibious Cascadia Initiative Seismic Array},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {126},
	number = {7},
	year = {2021},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2021JB022180},
	month = {06/2021},
	pages = {e2021JB022180},
	abstract = {Fault coupling is vital in determining the amount of strain that is accumulated along faults. The magnitude and location of stored elastic strain energy in highly coupled regions has important implications for understanding the full range of slip behavior at plate boundary faults, as well as earthquake and tsunami hazards. We use the temporary dense amphibious array of seismometers offered by the Cascadia Initiative to create a high-resolution catalog of events to examine the spatio-temporal behavior of earthquakes near the plate interface. The data show that in southern Cascadia the plate interface updip of the geodetically locked region is nearly devoid of seismicity, therefore likely highly coupled and accumulating strain. The catalog reveals events that are clustered at the downdip edge of the highly coupled megathrust that correlate in time with nearby strain transient observations. Template matching of events in the cluster using permanent stations of the Northern California Seismic Network over a 10-year period between 2010 and 2020 indicates that this cluster is unique in space and time. Its activity only during the strain transient provides support for the utility of seismic observations in the identification of strain transients.},
	keywords = {microseismicity, ocean bottom seismometers, plate interface, seismology, strain transient, template matching},
	issn = {2169-9356},
	doi = {10.1029/2021JB022180},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021JB022180},
	author = {Alongi, T. and Schwartz, S. Y. and Shaddox, H. R. and Small, D. T.}
}
@article {agius_thin_2021,
	title = {A thin mantle transition zone beneath the equatorial Mid-Atlantic Ridge},
	journal = {Nature},
	volume = {589},
	number = {7843},
	year = {2021},
	note = {Publisher: Nature Publishing Group},
	month = {01/2021},
	pages = {562{\textendash}566},
	abstract = {The location and degree of material transfer between the upper and lower mantle are key to the Earth{\textquoteright}s thermal and chemical evolution. Sinking slabs and rising plumes are generally accepted as locations of transfer1,2, whereas mid-ocean ridges are not typically assumed to have a role3. However, tight constraints from in situ measurements at ridges have proved to be challenging. Here we use receiver functions that reveal the conversion of primary to secondary seismic waves to image the discontinuities that bound the mantle transition zone, using ocean bottom seismic data from the equatorial Mid-Atlantic Ridge. Our images show that the seismic discontinuity at depths of~about 660~kilometres is broadly uplifted by 10~{\textpm}~4 kilometres over a swath about 600~kilometres wide and that the 410-kilometre discontinuity is depressed by 5~{\textpm}~4~kilometres. This thinning of the mantle transition zone is coincident with slow shear-wave velocities in the mantle, from global seismic tomography4{\textendash}7. In addition, seismic velocities in the mantle transition zone beneath the Mid-Atlantic Ridge are on average slower than those beneath older Atlantic Ocean seafloor. The observations imply material transfer from the lower to the upper mantle{\textemdash}either continuous or punctuated{\textemdash}that is linked to the Mid-Atlantic Ridge. Given the length and longevity of the mid-ocean ridge system, this implies that whole-mantle convection may be more prevalent than previously thought, with ridge upwellings having a role in counterbalancing slab downwellings.},
	keywords = {Geodynamics, Geophysics, seismology},
	issn = {1476-4687},
	doi = {10.1038/s41586-020-03139-x},
	url = {https://www.nature.com/articles/s41586-020-03139-x},
	author = {Agius, Matthew R. and Rychert, Catherine A. and Harmon, Nicholas and Tharimena, Saikiran and Kendall, J.-Michael}
}
@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 {harmon_evolution_2020,
	title = {Evolution of the Oceanic Lithosphere in the Equatorial Atlantic From Rayleigh Wave Tomography, Evidence for Small-Scale Convection From the PI-LAB Experiment},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {21},
	number = {9},
	year = {2020},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2020GC009174},
	month = {08/2020},
	pages = {e2020GC009174},
	abstract = {The oceanic lithosphere is a primary component of the plate tectonic system, yet its evolution and its asthenospheric interaction have rarely been quantified by in situ imaging at slow spreading systems. We use Rayleigh wave tomography from noise and teleseismic surface waves to image the shear wave velocity structure of the oceanic lithosphere-asthenosphere system from 0 to 80 My at the equatorial Mid-Atlantic Ridge using data from the Passive Imaging of the Lithosphere-Asthenosphere Boundary (PI-LAB) experiment. We observe fast lithosphere (VSV > 4.4 km/s) that thickens from 20{\textendash}30 km near the ridge axis to 70 km at seafloor >60 My. We observe several punctuated slow velocity anomalies (VSV < 4.1 km/s) in the asthenosphere between 50 and 150 km depth, not necessarily focused beneath the ridge axis. Some of the slow velocity regions are located within 100 km of the ridge axis, but other slow velocity regions are observed at distances > 400 km from the ridge. We observe a high velocity lithospheric downwelling drip beneath 30 My seafloor that extends to 80{\textendash}130 km depth. The asthenospheric slow velocities likely require partial melt. Although melt is present off axis, the lack of off-axis volcanism suggests the lithosphere acts as a permeability boundary for deeper melts. The punctuated and off-axis character of the asthenospheric anomalies and lithospheric drip suggests small-scale convection is active at a range of seafloor ages. Small-scale convection and/or more complex mantle flow may be aided by the presence of large offset fracture zones and/or the presence of melt and its associated low-viscosities and enhanced buoyancies.},
	keywords = {asthenosphere, Atlantic Ocean, oceanic lithosphere, PI-LAB, shear velocity, surface wave tomography},
	issn = {1525-2027},
	doi = {10.1029/2020GC009174},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020GC009174},
	author = {Harmon, Nicholas and Rychert, Catherine A. and Kendall, J. Michael and Agius, Matthew and Bogiatzis, Petros and Tharimena, Saikiran}
}
@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 {118,
	title = {Vp/Vs Ratio of Incoming Sediments Off Cascadia Subduction Zone From Analysis of Controlled-Source Multicomponent OBS Records},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {125},
	year = {2020},
	type = {Journal Article},
	abstract = {P-to-S-converted waves observed in controlled-source multicomponent ocean bottom seismometer (OBS) records were used to derive the Vp/Vs structure of Cascadia Basin sediments. We used P-to-S waves converted at the basement to derive an empirical function describing the average Vp/Vs of Cascadia sediments as a function of sediment thickness. We derived one-dimensional interval Vp/Vs functions from semblance velocity analysis of S-converted intrasediment and basement reflections, which we used to define an empirical Vp/Vs versus burial depth compaction trend. We find that seaward from the Cascadia deformation front, Vp/Vs structure offshore northern Oregon and Washington shows little variability along strike, while the structure of incoming sediments offshore central Oregon is more heterogeneous and includes intermediate-to-deep sediment layers of anomalously elevated Vp/Vs. These zones with elevated Vp/Vs are likely due to elevated pore fluid pressures, although layers of high sand content intercalated within a more clayey sedimentary sequence, and/or a higher content of coarser-grained clay minerals relative to finer-grained smectite could be contributing factors. We find that the proto-d{\'e}collement offshore central Oregon develops within the incoming sediments at a low-permeability boundary that traps fluids in a stratigraphic level where fluid overpressure exceeds 50\% of the differential pressure between the hydrostatic pressure and the lithostatic pressure. Incoming sediments with the highest estimated fluid overpressures occur offshore central Oregon where deformation of the accretionary prism is seaward vergent. Conversely, landward vergence offshore northern Oregon and Washington correlates with more moderate pore pressures and laterally homogeneous Vp/Vs functions of Cascadia Basin sediments. Average and interval Vp/Vs versus depth functions derived from S-converted waves from the Ridge-to-Trench seismic experiment in Cascadia Basin Layers with high Vp/Vs indicate elevated pore fluid pressure in incoming sediments Variations in Vp/Vs structure correlate with underthrust sediment thickness and wedge deformation style.},
	doi = {10.1029/2019jb019239},
	url = {https://app.dimensions.ai/details/publication/pub.1127957341},
	author = {Zhu, Jian and Canales, J. Pablo and Han, Shuoshuo and Carbotte, Suzanne M. and Arnulf, Adrien and Nedimovi{\'c}, Mladen R.}
}
@article {janiszewski_amphibious_2019,
	title = {Amphibious surface-wave phase-velocity measurements of the Cascadia subduction zone},
	journal = {Geophysical Journal International},
	volume = {217},
	number = {3},
	year = {2019},
	month = {jun},
	pages = {1929{\textendash}1948},
	abstract = {A new amphibious seismic data set from the Cascadia subduction zone is used to characterize the lithosphere structure from the Juan de Fuca ridge to the Cascades backarc. These seismic data are allowing the imaging of an entire tectonic plate from its creation at the ridge through the onset of the subduction to beyond the volcanic arc, along the entire strike of the Cascadia subduction zone. We develop a tilt and compliance correction procedure for ocean-bottom seismometers that employs automated quality control to calculate robust station noise properties. To elucidate crust and upper-mantle structure, we present shoreline-crossing Rayleigh-wave phase-velocity maps for the Cascadia subduction zone, calculated from earthquake data from 20 to 160 s period and from ambient-noise correlations from 9 to 20 s period. We interpret the phase-velocity maps in terms of the tectonics associated with the Juan de Fuca plate history and the Cascadia subduction system. We find that thermal oceanic plate cooling models cannot explain velocity anomalies observed beneath the Juan de Fuca plate. Instead, they may be explained by a <=1 per cent partial melt region beneath the ridge and are spatially collocated with patches of hydration and increased faulting in the crust and upper mantle near the deformation front. In the forearc, slow velocities appear to be more prevalent in areas that experienced high slip in past Cascadia megathrust earthquakes and generally occur updip of the highest-density tremor regions and locations of intraplate earthquakes. Beneath the volcanic arc, the slowest phase velocities correlate with regions of highest magma production volume.},
	issn = {0956-540X},
	doi = {10.1093/gji/ggz051},
	url = {https://doi.org/10.1093/gji/ggz051},
	author = {Janiszewski, Helen A and Gaherty, James B and Abers, Geoffrey A and Gao, Haiying and Eilon, Zachary C}
}
@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 {Arnoux2019,
	title = {Seismic Imaging and Physical Properties of the Endeavour Segment: Evidence that Skew Between Mantle and Crustal Magmatic Systems Governs Spreading Center Processes},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {20},
	number = {3},
	year = {2019},
	month = {mar},
	pages = {1319{\textendash}1339},
	issn = {1525-2027},
	doi = {10.1029/2018GC007978},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GC007978},
	author = {Arnoux, G. M. and Toomey, D. R. and Hooft, E. E. E. and Wilcock, W. S. D.}
}
@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 {li_connections_2018,
	title = {Connections between subducted sediment, pore-fluid pressure, and earthquake behavior along the Alaska megathrust},
	journal = {Geology},
	volume = {46},
	number = {4},
	year = {2018},
	month = {02/2018},
	pages = {299{\textendash}302},
	abstract = {Variations in pore-fluid pressure along subduction megathrusts are often invoked to explain differences in fault slip behavior between margins. However, many other parameters vary between subduction zones, making it difficult to isolate the causes of elevated pore fluid pressures and their effects on megathrust behavior. Here we show evidence from pre-stack depth migrations of multichannel seismic reflection data along the subduction zone off the Alaska Peninsula for significant, systematic along-strike variations in the thickness, continuity, P-wave velocity, and estimated pore-fluid pressure of the subducting sediment layer that lines the shallow plate interface within 25 km of the trench. These variations appear to correlate with changes in seismicity, locking, and earthquake rupture history. The currently locked and seismically quiet Semidi segment has a continuous, thick (600{\textendash}900 m) subducted sediment layer that is characterized by low seismic velocities and elevated pore pressure (λ* ≈ 0.4{\textendash}0.8). The subducted sediment in the neighboring Shumagin Gap, a region with low geodetic coupling and abundant small earthquakes, is thinner, irregular and has lower pore pressure (λ* \&lt; 0.2{\textendash}0.3). We suggest that the thicker and weakly faulted sediment layer entering the trench at Semidi is associated with a continuous and overpressured sediment layer lining the shallow plate interface, but forms a large coherent asperity as it dewaters and consolidates at greater depths, thus favoring large earthquakes. In contrast, thinner incoming sediment disrupted by outer rise faulting at Shumagin results in a plate interface without elevated pore-fluid pressures, but which is heterogeneous and complex at all depths, contributing to creep and frequent small earthquakes.},
	issn = {0091-7613},
	doi = {10.1130/G39557.1},
	url = {https://doi.org/10.1130/G39557.1},
	author = {Li, Jiyao and Shillington, Donna J. and Saffer, Demian M. and B{\'e}cel, Anne and Nedimovi{\'c}, Mladen R. and Kuehn, Harold and Webb, Spahr C. and Keranen, Katie M. and Abers, Geoffrey A.}
}
@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 {agius_sediment_2018,
	title = {Sediment Characterization at the Equatorial Mid-Atlantic Ridge From P-to-S Teleseismic Phase Conversions Recorded on the PI-LAB Experiment},
	journal = {Geophysical Research Letters},
	volume = {45},
	number = {22},
	year = {2018},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2018GL080565},
	month = {11/2018},
	pages = {12,244{\textendash}12,252},
	abstract = {Accurate marine sediment characteristics, for example, thickness and seismic velocity, are important for constraining sedimentation rates with implications for climate variations and for seismic imaging of deeper structures using ocean bottom seismic deployments. We analyze P-to-S seismic phase conversions from the sediment-crust boundary recorded by the Passive Imaging of the Lithosphere-Asthenosphere Boundary (PI-LAB) experiment to infer the sediment thickness across the Mid-Atlantic Ridge covering 0- to 80-Myr-old seafloor. We find Pds-P delay times of 0.04{\textendash}0.37 s, or 5- to 82-m thickness. Sediment thickness increases with age. Thickness agrees with global estimates for young (<15{\textendash}20 Myr) seafloor but is thinner on older lithosphere. Our result may represent a lower limit on sediment thickness, given that several of our stations are on topographic highs. The sedimentation rate decrease observed from 5 to 1.2 mm/kyr at \~{}10 Myr suggests a recent increase in productivity related to climate change, eolian dust fluxes, and/or biogenic marine activity.},
	keywords = {equatorial Mid-Atlantic Ridge, PI-LAB, sediments},
	issn = {1944-8007},
	doi = {10.1029/2018GL080565},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GL080565},
	author = {Agius, M. R. and Harmon, N. and Rychert, C. A. and Tharimena, S. and Kendall, J.-M.}
}
@article {Eilon2017,
	title = {High seismic attenuation at a mid-ocean ridge reveals the distribution of deep melt},
	journal = {Science Advances},
	volume = {3},
	number = {5},
	year = {2017},
	month = {may},
	pages = {e1602829},
	issn = {2375-2548},
	doi = {10.1126/sciadv.1602829},
	url = {https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.1602829},
	author = {Eilon, Zachary C. and Abers, Geoffrey A.}
}
@conference {Shi2017,
	title = {Mapping coherent, time-varying wavefronts from the 2011 Tohoku tsunami into enhanced, time-dependent warning messages},
	booktitle = {16th World Conference on Earthquake Engineering},
	year = {2017},
	url = {https://resolver.caltech.edu/CaltechAUTHORS:20170127-163908004},
	author = {Shi, J. and Kohler, M.D. and Sutton, J.N. and Ampuero, J.P.}
}
@article {Agius2017,
	title = {Mapping the mantle transition zone beneath Hawaii from Ps receiver functions: Evidence for a hot plume and cold mantle downwellings},
	journal = {Earth and Planetary Science Letters},
	volume = {474},
	year = {2017},
	month = {sep},
	pages = {226{\textendash}236},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2017.06.033},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X17303497},
	author = {Agius, Matthew R. and Rychert, Catherine A. and Harmon, Nicholas and Laske, Gabi}
}
@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 {Canales2017,
	title = {Seismic imaging of magma sills beneath an ultramafic-hosted hydrothermal system},
	journal = {Geology},
	volume = {45},
	number = {5},
	year = {2017},
	month = {may},
	pages = {451{\textendash}454},
	issn = {0091-7613},
	doi = {10.1130/G38795.1},
	url = {https://pubs.geoscienceworld.org/geology/article/45/5/451-454/207914},
	author = {Canales, J. Pablo and Dunn, Robert A. and Arai, Ryuta and Sohn, Robert A.}
}
@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 {Dunn2017,
	title = {Three-Dimensional Seismic Structure of the Mid-Atlantic Ridge: An Investigation of Tectonic, Magmatic, and Hydrothermal Processes in the Rainbow Area},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {122},
	number = {12},
	year = {2017},
	month = {dec},
	pages = {9580{\textendash}9602},
	issn = {21699313},
	doi = {10.1002/2017JB015051},
	url = {http://doi.wiley.com/10.1002/2017JB015051},
	author = {Dunn, Robert A. and Arai, Ryuta and Eason, Deborah E. and Canales, J. Pablo and Sohn, Robert A.}
}
@article {becel_tsunamigenic_2017,
	title = {Tsunamigenic structures in a creeping section of the Alaska subduction zone},
	journal = {Nature Geoscience},
	volume = {10},
	number = {8},
	year = {2017},
	note = {Publisher: Nature Publishing Group},
	pages = {609{\textendash}613},
	abstract = {Segments of subduction zones that are capable of generating tsunamigenic earthquakes appear to have characteristic structural configurations. These structures include heterogeneous plate interfaces, a small wedge of deformed sediment at the toe of the overriding plate (the frontal prism), and splay faults in the crust of the overriding plate that root within the plate boundary megathrust. Here we use seismic reflection imaging to show that these features also exist within a creeping segment of the Alaska subduction zone, the Shumagin Gap. We identify an active crustal-scale normal fault system that dips landward and resembles that involved in the 2011 Tohoku-oki earthquake in Japan. We also find that the Shumagin Gap has a small frontal prism, a deep-water splay fault, and that the plate interface here is rough and thinly sedimented. We propose that lateral propagation of rupture from a neighbouring segment into the Shumagin Gap may explain a tsunamigenic earthquake that occurred there in 1788 and that tsunamigenic potential should be considered in hazard assessments for the region. Our results demonstrate that structural configurations similar to those in Tohoku may exist in other subduction zones, including within creeping segments or segments with no record of historical megathrust earthquakes, but are under-recognized. Identifying similar configurations globally may improve our ability to anticipate regions capable of generating large tsunamis.},
	keywords = {Geodynamics, Geology, Natural hazards, seismology, Tectonics},
	issn = {1752-0908},
	doi = {10.1038/ngeo2990},
	url = {https://www.nature.com/articles/ngeo2990},
	author = {B{\'e}cel, Anne and Shillington, Donna J. and Delescluse, Matthias and Nedimovi{\'c}, Mladen R. and Abers, Geoffrey A. and Saffer, Demian M. and Webb, Spahr C. and Keranen, Katie M. and Roche, Pierre-Henri and Li, Jiyao and Kuehn, Harold}
}
@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 {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 {Peureux2016,
	title = {Ocean bottom pressure records from the Cascadia array and short surface gravity waves},
	journal = {Journal of Geophysical Research: Oceans},
	volume = {121},
	number = {5},
	year = {2016},
	month = {may},
	pages = {2862{\textendash}2873},
	issn = {2169-9275},
	doi = {10.1002/2015JC011580},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2015JC011580},
	author = {Peureux, Charles and Ardhuin, Fabrice}
}
@article {Audet2016,
	title = {Receiver functions using OBS data: promises and limitations from numerical modelling and examples from the Cascadia Initiative},
	journal = {Geophysical Journal International},
	volume = {205},
	number = {3},
	year = {2016},
	month = {jun},
	pages = {1740{\textendash}1755},
	issn = {0956-540X},
	doi = {10.1093/gji/ggw111},
	url = {https://academic.oup.com/gji/article-lookup/doi/10.1093/gji/ggw111},
	author = {Audet, Pascal}
}
@article {Abers2016,
	title = {Southeast Papuan crustal tectonics: Imaging extension and buoyancy of an active rift},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {121},
	number = {2},
	year = {2016},
	month = {feb},
	pages = {951{\textendash}971},
	issn = {2169-9313},
	doi = {10.1002/2015JB012621},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2015JB012621},
	author = {Abers, G. A. and Eilon, Z. and Gaherty, J. B. and Jin, G. and Kim, YH. and Obrebski, M. and Dieck, C.}
}
@article {Hawley2016,
	title = {Tomography reveals buoyant asthenosphere accumulating beneath the Juan de Fuca plate},
	journal = {Science},
	volume = {353},
	number = {6306},
	year = {2016},
	month = {sep},
	pages = {1406{\textendash}1408},
	issn = {0036-8075},
	doi = {10.1126/science.aad8104},
	url = {https://www.sciencemag.org/lookup/doi/10.1126/science.aad8104},
	author = {Hawley, W. B. and Allen, R. M. and Richards, M. A.}
}
@article {Lin2015,
	title = {The 11 March 2011 Tohoku tsunami wavefront mapping across offshore Southern California},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {120},
	number = {5},
	year = {2015},
	month = {may},
	pages = {3350{\textendash}3362},
	issn = {21699313},
	doi = {10.1002/2014JB011524},
	url = {http://doi.wiley.com/10.1002/2014JB011524},
	author = {Lin, Fan-Chi and Kohler, Monica D. and Lynett, Patrick and Ayca, Aykut and Weeraratne, Dayanthie S.}
}
@article {Janiszewski2015,
	title = {Imaging the Plate Interface in the Cascadia Seismogenic Zone: New Constraints from Offshore Receiver Functions},
	journal = {Seismological Research Letters},
	volume = {86},
	number = {5},
	year = {2015},
	month = {sep},
	pages = {1261{\textendash}1269},
	issn = {0895-0695},
	doi = {10.1785/0220150104},
	url = {https://pubs.geoscienceworld.org/srl/article/86/5/1261-1269/315535},
	author = {Janiszewski, Helen A. and Abers, Geoffrey A.}
}
@article {shillington_link_2015,
	title = {Link between plate fabric, hydration and subduction zone seismicity in Alaska},
	journal = {Nature Geoscience},
	volume = {8},
	number = {12},
	year = {2015},
	note = {Publisher: Nature Publishing Group},
	pages = {961{\textendash}964},
	abstract = {Subduction carries water into the Earth where it can influence seismicity. Analysis of the structure of the Alaskan subduction zone suggests fluid delivery is influenced by faults in the oceanic plate that formed at the mid-ocean ridge.},
	keywords = {Geodynamics, seismology, Tectonics},
	issn = {1752-0908},
	doi = {10.1038/ngeo2586},
	url = {https://www.nature.com/articles/ngeo2586},
	author = {Shillington, Donna J. and B{\'e}cel, Anne and Nedimovi{\'c}, Mladen R. and Kuehn, Harold and Webb, Spahr C. and Abers, Geoffrey A. and Keranen, Katie M. and Li, Jiyao and Delescluse, Matthias and Mattei-Salicrup, Gabriel A.}
}
@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.}
}
@inbook {Cheng2015,
	title = {Seismic Constraints on a Double-Layered Asymmetric Whole-Mantle Plume Beneath Hawai{\textquoteleft}i},
	year = {2015},
	month = {feb},
	pages = {19{\textendash}34},
	doi = {10.1002/9781118872079.ch2},
	url = {http://doi.wiley.com/10.1002/9781118872079.ch2},
	author = {Cheng, Cheng and Allen, Richard M. and Porritt, Rob W. and Ballmer, Maxim D.}
}
@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 {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 {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 {sutherland_middle_2012,
	title = {Middle Miocene to early Pliocene oblique extension in the southern Gulf of California},
	journal = {Geosphere},
	volume = {8},
	number = {4},
	year = {2012},
	month = {aug},
	pages = {752{\textendash}770},
	abstract = {A multichannel seismic (MCS) experiment spanning 600 km across the Alarc{\'o}n Rise and its conjugate rifted margins in the southern Gulf of California (western North America) provides insight into the spatial and temporal evolution of extension between Baja California and the mainland (Mexico). Stratigraphic analysis of multiple rift basins within the Alarc{\'o}n spreading corridor indicates an initial stage of oblique extension starting ca. 14{\textendash}12 Ma. This initial phase of extension was characterized by the formation of several large basins in the center of the gulf and on the southeast margin with negligible synrift sedimentation. A second phase of oblique extension, likely synchronous with large-scale basin opening in the central and northern Gulf of California, began ca. 8{\textendash}5 Ma and was characterized by the formation of smaller half-grabens distributed across the conjugate margins that contain both synrift and postrift deposits. A key feature imaged within the MCS data is a highly reflective, ropey layer at the top of basement, interpreted to be either volcanic rocks from the 25{\textendash}12 Ma Comond{\'u} Group, and/or early rifting volcanic rocks that are between 11 and 9 Ma, or younger. This volcanic layer is extensively faulted, suggesting that it predates the episode of early extension. Upper crustal extension appears to be equally distributed across conjugate margins, forming a symmetrical continental rift. Two styles of rifted basin are observed; older basins (estimated as 14{\textendash}11 Ma using sedimentation rates) show distributed extension with extensive basement faulting. In contrast, the younger basins (likely post{\textendash}6 Ma) are asymmetrical with synrift deposits thickening into the basin-bounding faults. The northeast-southwest geomorphic expression of the Tamayo bank and trough and other features provides additional evidence that northwest-southeast oblique extension began ca. 12 Ma. These new spatial and temporal constraints, when combined with a crustal thickness profile obtained across the entire Alarc{\'o}n corridor, suggest that significant northwest-southeast oblique extension within the Gulf of California started well before 6 Ma, in contrast to earlier models.},
	issn = {1553-040X},
	doi = {10.1130/GES00770.1},
	url = {https://doi.org/10.1130/GES00770.1},
	author = {Sutherland, Fiona H. and Kent, Graham M. and Harding, Alistair J. and Umhoefer, Paul J. and Driscoll, Neal W. and Lizarralde, Daniel and Fletcher, John M. and Axen, Gary J. and Holbrook, W. Steven and Gonz{\'a}lez-Fern{\'a}ndez, Antonio and Lonsdale, Peter}
}
@article {anchieta_seismicity_2011,
	title = {Seismicity around the Hawaiian Islands Recorded by the PLUME Seismometer Networks: Insight into Faulting near Maui, Molokai, and Oahu},
	journal = {Bulletin of the Seismological Society of America},
	volume = {101},
	number = {4},
	year = {2011},
	month = {aug},
	pages = {1742{\textendash}1758},
	abstract = {Instrumental limitations have long prevented the detailed characterization of offshore earthquakes around the Hawaiian Islands, and little is known about the spatial distribution of earthquakes in regions outside the vicinity of the well-monitored island of Hawaii. Here, we analyze data from the deployment of two successive networks of ocean-bottom seismometers (OBSs) as part of the Plume-Lithosphere Undersea Melt Experiment (PLUME) to better determine seismicity patterns along the Hawaiian Islands and their offshore regions. We find that earthquake detection rates are improved when seismograms are high-pass filtered above \~{}5 Hz to reduce the background seismic noise. Hypocentral solutions have been determined for 1147 previously undetected microearthquakes, and an additional 2880 events correspond to earthquakes already in the catalog of the United States Geological Survey (USGS) Hawaiian Volcano Observatory (HVO). The spatial patterns of earthquakes identified solely on the PLUME network provide complementary information to patterns identified by the HVO network. A diffuse pattern of seismicity is found to the southeast of the island of Hawaii, and clusters of earthquakes are located west of the island. Many microearthquakes are observed in the vicinity of Maui and Molokai, including some located at mantle depths. A small number of microearthquakes are found to occur near Oahu. There is no evidence from our analyses that the Molokai fracture zone (MFZ) is seismically active at this time, and no evidence was found of a previously hypothesized Diamond Head fault (DHF) near Oahu. However, on the basis of both the PLUME and HVO locations, there is a northeast{\textendash}southwest{\textendash}trending swath of epicenters extending northeastward of Oahu that may indicate the locus of moderate-sized historic earthquakes attributed to the Oahu region.},
	issn = {0037-1106},
	doi = {10.1785/0120100271},
	url = {https://doi.org/10.1785/0120100271},
	author = {Anchieta, Maria C. and Wolfe, Cecily J. and Pavlis, Gary L. and Vernon, Frank L. and Eakins, Jennifer A. and Solomon, Sean C. and Laske, Gabi and Collins, John A.}
}
@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 {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 {lizarralde_variation_2007,
	title = {Variation in styles of rifting in the Gulf of California},
	journal = {Nature},
	volume = {448},
	number = {7152},
	year = {2007},
	note = {Number: 7152 Publisher: Nature Publishing Group},
	month = {jul},
	pages = {466{\textendash}469},
	abstract = {Results from the PESCADOR seismic experiment in the Gulf of California provide new insight into rifting {\textemdash} the process that ruptures continents and forms new ocean basins. Unpredicted variations in magmatic activity in continental rifts are commonly attributed to variations in mantle temperature, but such thermal variations tend to occur over large length scales. The new results reveal large differences in rifting style and magmatism over short lateral distances. This suggests that the observed range in magmatism is caused not by variation in temperature, but rather by variability in mantle composition and fertility {\textemdash} the intrinsic capacity of the underlying mantle to produce melt.},
	keywords = {Humanities and Social Sciences, multidisciplinary, Science},
	issn = {1476-4687},
	doi = {10.1038/nature06035},
	url = {https://www.nature.com/articles/nature06035},
	author = {Lizarralde, Daniel and Axen, Gary J. and Brown, Hillary E. and Fletcher, John M. and Gonz{\'a}lez-Fern{\'a}ndez, Antonio and Harding, Alistair J. and Holbrook, W. Steven and Kent, Graham M. and Paramo, Pedro and Sutherland, Fiona and Umhoefer, Paul J.}
}
