@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 {rebeyrol_revisiting_2024,
	title = {Revisiting the OBS seafloor compliance signal removal with a stationarity and stacking-based approach: the BRUIT-FM toolbox},
	journal = {Geophysical Journal International},
	volume = {239},
	year = {2024},
	month = {10/2024},
	pages = {386{\textendash}401},
	abstract = {This study focuses on improving the seafloor compliance noise removal method, which relies on estimates of the compliance transfer function frequency response (the deformation of the seafloor under long-period pressure waves). We first propose a new multi-scale deviation analysis of broadband ocean bottom seismometer data to evaluate stationarity properties that are key to the subsequent analysis. We then propose a new approach to removing the compliance noise from the vertical channel data, by stacking daily estimated transfer function frequency responses over a period of time. We also propose an automated transient event detection and data selection method based on a cross-correlation criterion. As an example, we apply the method to data from the Cascadia Initiative (network 7D2011). We find that the spectral extent of long-period forcing waves varies significantly over time so that standard daily transfer function calculation techniques poorly estimate the transfer function frequency response at the lowest frequencies, resulting in poor denoising performance. The proposed method more accurately removes noise at these lower frequencies, especially where coherence is low, reducing the mean deviation of the signal in our test case by 27 \% or more. We also show that our calculated transfer functions can be transfered across time periods. The method should allow better estimates of seafloor compliance and help to remove compliance noise at stations with low pressure-acceleration coherence. Our results can be reproduced using the BRUIT-FM Python toolbox, available at https://gitlab.ifremer.fr/anr-bruitfm/bruit-fm-toolbox.},
	issn = {1365-246X},
	doi = {10.1093/gji/ggae265},
	url = {https://doi.org/10.1093/gji/ggae265},
	author = {Rebeyrol, Simon and Ker, St{\'e}phan and Duval, Laurent and Crawford, Wayne C}
}
@article {sahoo_tidal_2024,
	title = {Tidal triggering of seismic swarm associated with hydrothermal circulation at Blanco ridge transform fault zone, Northeast Pacific},
	journal = {Physics of the Earth and Planetary Interiors},
	volume = {356},
	year = {2024},
	month = {11/2024},
	pages = {107259},
	abstract = {Seismicity associated with hydrothermal systems (e.g., submarine volcanoes, mid-oceanic ridges, oceanic transform faults, etc.) share a complex relationship with the tidal forcing and induced fluid flow process under different tectonic settings. The hydrothermal circulation drives the deformation at the brittle-ductile transition zone within a permeable brittle crust. Although the tidal loading amplitudes are too small to generate a brittle deformation, the incremental pressure exerted by the tidal loading can modulate the flow of hydrothermal fluid circulation and trigger the critically stressed faults or fracture zones. We present a compelling case of tidal modulation in seismicity along the Blanco Ridge Transform Fault Zone (BRTFZ), in the northeast Pacific. The strong diurnal and fortnightly periodicity has been observed in the deeper seismic swarm (7{\textendash}15~km), whereas the shallow seismic swarm (0{\textendash}7~km) does not exhibit any such tidal periodicity. The dominance of diurnal and fortnightly periodicity in the deeper seismic swarm is explained by the high amplitude tidal cycles providing additional stress on the fluid circulation at the crust-mantle boundary. Moreover, our robust statistical correlation of seismicity with tidal stress and resonance destabilization model under rate-and-state friction formalism suggests that the fault segments are conditionally unstable and more sensitive to periodic tidal stress perturbation.},
	keywords = {Hydrothermal fluid, Ocean transform fault, Resonance destabilization, Seismic swarm, Tidal periodicity},
	issn = {0031-9201},
	doi = {10.1016/j.pepi.2024.107259},
	url = {https://www.sciencedirect.com/science/article/pii/S0031920124001171},
	author = {Sahoo, Sambit and Senapati, Batakrushna and Panda, Dibyashakti and Jin, Shuanggen and Kundu, Bhaskar}
}
@article {trehu_deformation_2023,
	title = {Deformation of the Juan de Fuca Plate Beneath the Central Cascadia Continental Margin (44{\textdegree}-45{\textdegree}N) in Response to an Upper Plate Load},
	journal = {Earth Science, Systems and Society},
	volume = {3},
	year = {2023},
	note = {Publisher: Frontiers},
	month = {11/2023},
	pages = {10085},
	abstract = {A 3D crustal model for the central Cascadia continental shelf and Coast Range between 44{\textdegree}N and 45{\textdegree}N shows that the crystalline crust of the forearc wedge beneath the coastline is characterized by a NW-trending, vertical slab of high-velocity rock interpreted to represent the dike complex that fed the Yachats basaltsBasalt, which werewas intruded into the forearc approximately 3637 million years ago. A spatial correlation is observed between downward deflection of the crust of the subducting Juan de Fuca plate, inferred from inversion of PmP arrivals to image the Moho surface, and the high velocity (and consequently high density) dike complex.anomaly underlying the Yachats Basalt. Apparent subsequent rebound of the subducting plate at greater depth suggests a primarily elastic response of the subducting plate to this load. Calculations for a range of plausible values for the magnitude of the load and the width and depth of the depression indicate that that the effective elastic thickness of the subducted Juan de Fuca plate is \textasciitilde2-<6 km. Although our simple analytical models do not include partial support of the load of the slab by the adjacent upper plate crust or time dependence to account for the motion of the slab beneath the load, incorporation of those effects should decrease rather than increase the apparent strength of the subducted plate. We conclude that the subducted Juan de Fuca plate beneath the central Oregon margin is elastically thin and has the potential to store elastic strain energy before rupturing. Our model of a well-defined, focused and static upper plate load that locally deforms the subducted plate within the nominally seismogenic or transitional part of the Cascadia plate boundary may be unique in providing a relatively straightforward scenario for estimating the mechanical properties of the subducted Juan de Fuca plate. We extrapolate from these results to speculate that elastic deformation of the subducting plate may contribute to the low level of seismicity throughout much of the Cascadia forearc in inter-seismic period between great earthquakes but note that our local results do not preclude faulting or elasto-plastic deformation of a thin and weak plate as it subducts.},
	issn = {2634-730X},
	doi = {10.3389/esss.2023.10085},
	url = {https://www.escubed.org/articles/10.3389/esss.2023.10085/full},
	author = {Tr{\'e}hu, Anne M. and Davenport, Kathy and Kenyon, Christopher B. and Carbotte, Suzanne M. and N{\'a}b{\v e}lek, John L. and Toomey, Douglas R. and Wilcock, William S. D.}
}
@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 {farrell_relationship_2023,
	title = {The Relationship Between Wind, Waves, Bathymetry, and Microseisms in Yellowstone Lake, Yellowstone National Park},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {128},
	number = {7},
	year = {2023},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2022JB025943},
	month = {06/2023},
	pages = {e2022JB025943},
	abstract = {We conducted a multidisciplinary geophysical experiment to study the relationship between wind, waves, bathymetry, and microseisms in Yellowstone Lake{\textemdash}a small, isolated body of water in which wind-driven gravity waves excite low-amplitude seismic energy at periods \~{}1.0 s with a regular daily pattern. During 25 June{\textendash}4 August 2018, we deployed 40 short-period seismometers, four meteorological stations, and two wave gauges in and around Yellowstone Lake. These instruments were complemented by seven permanent seismometers on the lake perimeter, and a contemporaneous deployment of 10 lake bottom seismometers (LBS) on the floor of the north-central portion of the lake. The daily wind cycle, with southwesterly winds rising from \~{}0 m/s in the early morning to maxima of 10{\textendash}15 m/s in the late afternoon, generated lake waves with significant heights of \~{}0.3{\textendash}0.4 m and dominant periods of 1.5{\textendash}2.5 s, which in turn generated microseisms with dominant periods of \~{}0.8{\textendash}1.2 s, in excellent agreement with the double-frequency generation mechanism. Microseism energy was strongest on the lake floor stations, followed by the island stations and those along the northeastern coast of the lake, suggesting that these sites are closest to the source region where interference between incident and shoreline-reflected waves is responsible for microseism generation. Smaller amplitude single-frequency microseism energy was observed primarily along the northeastern lake shoreline. Both types of microseism energy are sensitive to shoreline morphology and lake wave dynamics, such that long-term monitoring of lake microseisms may further our understanding of how these processes change over time.},
	issn = {2169-9356},
	doi = {10.1029/2022JB025943},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022JB025943},
	author = {Farrell, Jamie and Koper, Keith D. and Sohn, Robert A.}
}
@article {leptokaropoulos_seismicity_2023,
	title = {Seismicity Properties of the Chain Transform Fault Inferred Using Data From the PI-LAB Experiment},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {128},
	number = {3},
	year = {2023},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2022JB024804},
	month = {02/2023},
	pages = {e2022JB024804},
	abstract = {Oceanic transform faults are intriguing in that they do not produce earthquakes as large as might be expected given their dimensions. We use 1-year of local seismicity (370 events above MC = 2.3) recorded on an array of ocean bottom seismometers (OBSs) and geophysical data to study the seismotectonic properties of the Chain transform, located in the equatorial Mid-Atlantic. We extend our analysis back in time by considering stronger earthquakes (MW >= 5.0) from global catalogs. We divide Chain into three areas (east, central, and west) based on historical event distribution, morphology, and multidimensional OBS seismicity cluster analysis. Seismic activity recorded by the OBS is the highest at the eastern area of Chain where there is a lozenge-shaped topographic high, a negative rMBA gravity anomaly, and only a few historical MW >= 5.5 events. OBS seismicity rates are lower in the western and central areas. However, these areas accommodate the majority of seismic moment release, as inferred from both OBS and historical data. Higher b-values are significantly correlated with lower rMBA and with shallower bathymetry, potentially related to thickened crust. Our results suggest high lateral heterogeneity along Chain. Patches with moderate to low OBS seismicity rates that occasionally host MW >= 6.0 earthquakes are interrupted by segments with abundant OBS activity but few historical events with 5.5 <= MW < 6.0. This segmentation is possibly due to variable fluid circulation and alteration, which may also change in time.},
	keywords = {fault segmentation, Mid Atlantic Ridge, OBS seismicity, oceanic transform faults, seismotectonics},
	issn = {2169-9356},
	doi = {10.1029/2022JB024804},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022JB024804},
	author = {Leptokaropoulos, K. and Rychert, C. A. and Harmon, N. and Kendall, J. M.}
}
@article {262,
	title = {Slab to back-arc to arc: Fluid and melt pathways through the mantle wedge beneath the Lesser Antilles},
	journal = {Science Advances},
	volume = {9},
	year = {2023},
	month = {02/2023},
	pages = {eadd2143},
	abstract = {Volatiles expelled from subducted plates promote melting of the overlying warm mantle, feeding arc volcanism. However, debates continue over the factors controlling melt generation and transport, and how these determine the placement of volcanoes. To broaden our synoptic view of these fundamental mantle wedge processes, we image seismic attenuation beneath the Lesser Antilles arc, an end-member system that slowly subducts old, tectonized lithosphere. Punctuated anomalies with high ratios of bulk-to-shear attenuation (Qκ-1/Qμ-1 > 0.6) and VP/VS (>1.83) lie 40 km above the slab, representing expelled fluids that are retained in a cold boundary layer, transporting fluids toward the back-arc. The strongest attenuation (1000/QS ~ 20), characterizing melt in warm mantle, lies beneath the back-arc, revealing how back-arc mantle feeds arc volcanoes. Melt ponds under the upper plate and percolates toward the arc along structures from earlier back-arc spreading, demonstrating how slab dehydration, upper-plate properties, past tectonics, and resulting melt pathways collectively condition volcanism.},
	keywords = {3706 Geophysics},
	issn = {2375-2548},
	doi = {10.1126/sciadv.add2143},
	url = {https://www.science.org/doi/10.1126/sciadv.add2143},
	author = {Hicks, SP and Bie, L and Rychert, CA and Harmon, N and Goes, S and Rietbrock, A and Wei, SS and Collier, JS and Henstock, TJ and Lynch, L and Prytulak, J and Macpherson, CG and Schlaphorst, D and Wilkinson, JJ and Blundy, JD and Cooper, GF and Davy, RG and Kendall, J-M and VOILA WORKING GROUP}
}
@article {kleckner_automated_2021,
	title = {Automated Detection of Clipping in Broadband Earthquake Records},
	journal = {Seismological Research Letters},
	volume = {93},
	number = {2A},
	year = {2021},
	month = {dec},
	pages = {880{\textendash}896},
	abstract = {Because the amount of available ground-motion data has increased over the last decades, the need for automated processing algorithms has also increased. One difficulty with automated processing is to screen clipped records. Clipping occurs when the ground-motion amplitude exceeds the dynamic range of the linear response of the instrument. Clipped records in which the amplitude exceeds the dynamic range are relatively easy to identify visually yet challenging for automated algorithms. In this article, we seek to identify a reliable and fully automated clipping detection algorithm tailored to near-real-time earthquake response needs. We consider multiple alternative algorithms, including (1)~an algorithm based on the percentage difference in adjacent data points, (2)~the standard deviation of the data within a moving window, (3)~the shape of the histogram of the recorded amplitudes, (4)~the second derivative of the data, and (5)~the amplitude of the data. To quantitatively compare these algorithms, we construct development and holdout datasets from earthquakes across a range of geographic regions, tectonic environments, and instrument types. We manually classify each record for the presence of clipping and use the classified records. We then develop an artificial neural network model that combines all the individual algorithms. Testing on the holdout dataset, the standard deviation and histogram approaches are the most accurate individual algorithms, with an overall accuracy of about 93\%. The combined artificial neural network method yields an overall accuracy of 95\%, and the choice of classification threshold can balance precision and recall.},
	issn = {0895-0695},
	doi = {10.1785/0220210028},
	url = {https://doi.org/10.1785/0220210028},
	author = {Kleckner, James K. and Withers, Kyle B. and Thompson, Eric M. and Rekoske, John M. and Wolin, Emily and Moschetti, Morgan P.}
}
@article {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 {saikia_seismic_2021,
	title = {Seismic Attenuation at the Equatorial Mid-Atlantic Ridge Constrained by Local Rayleigh Wave Analysis From the PI-LAB Experiment},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {22},
	number = {12},
	year = {2021},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2021GC010085},
	month = {12/2021},
	pages = {e2021GC010085},
	abstract = {The ocean lithosphere represents a simple realisation of the tectonic plate, offering a unique opportunity to better understand its physical and chemical properties in relationship to those of the underlying asthenosphere. While seismic velocity is frequently used to image the plate, seismic attenuation (Qμ-1) offers an important complimentary observation. We use fundamental mode Rayleigh waves from 17 local, M > 4.2 earthquakes recorded at stations located on 0{\textendash}80 My old lithosphere near the equatorial Mid-Atlantic Ridge. We determine the attenuation coefficient () for periods between 15 and 40 s and invert for 1-D average shear wave quality factor values () and shear wave velocity (Vs). We find values of 175 {\textpm} 16 at 50 km depth, decreasing to 90 {\textpm} 15 at greater than 60 km. Comparison of our and Vs measurements to previous observations from oceanic settings shows agreement in terms of higher and Vs in the lithosphere in comparison to the asthenosphere. The observations from oceanic settings are in general agreement with the laboratory predictions for -Vs relationships for thermal models. However, a small amount of partial melt (1\%) is required to explain several previous observations. Our result also compares favorably to previous observations of lithospheric and asthenospheric attenuation with respect to frequency. Melt is not required for the 1-D average of our study area, consistent with previous electromagnetic and seismic imaging that suggested melt in punctuated and/or thin channel anomalies rather than over broad regions of the mantle.},
	keywords = {attenuation, Mid Atlantic Ridge, surface wave},
	issn = {1525-2027},
	doi = {10.1029/2021GC010085},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021GC010085},
	author = {Saikia, Utpal and Rychert, Catherine A. and Harmon, Nicholas and Michael Kendall, J.}
}
@article {kuna_seismic_2021,
	title = {Seismic crustal imaging using fin whale songs},
	journal = {Science},
	volume = {371},
	number = {6530},
	year = {2021},
	note = {Publisher: American Association for the Advancement of Science},
	month = {02/2021},
	pages = {731{\textendash}735},
	abstract = {Fin whale calls are among the strongest animal vocalizations that are detectable over great distances in the oceans. We analyze fin whale songs recorded at ocean-bottom seismometers in the northeast Pacific Ocean and show that in addition to the waterborne signal, the song recordings also contain signals reflected and refracted from crustal interfaces beneath the stations. With these data, we constrain the thickness and seismic velocity of the oceanic sediment and basaltic basement and the P-wave velocity of the gabbroic lower crust beneath and around the ocean bottom seismic stations. The abundant and globally available fin whale calls may be used to complement seismic studies in situations where conventional air-gun surveys are not available.},
	doi = {10.1126/science.abf3962},
	url = {https://www.science.org/doi/10.1126/science.abf3962},
	author = {Kuna, V{\'a}clav M. and N{\'a}b{\v e}lek, John L.}
}
@article {harmon_shear_2021,
	title = {Shear Velocity Inversion Guided by Resistivity Structure From the PI-LAB Experiment for Integrated Estimates of Partial Melt in the Mantle},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {126},
	number = {8},
	year = {2021},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2021JB022202},
	month = {08/2021},
	pages = {e2021JB022202},
	abstract = {The lithosphere-asthenosphere system is fundamental to our understanding of mantle convection and plate tectonics. The different sensitivities of seismic and electromagnetic methods can be used together to better constrain the properties of the system. Here, we re-examine the shear velocity model from Rayleigh waves in light of the magnetotelluric based resistivity models from the Passive Imaging of the Lithosphere Asthenosphere Boundary (PI-LAB) experiment near the equatorial Mid-Atlantic Ridge, with the goal of generating a structurally consistent velocity and resistivity model for the region. Cross-plots of the models suggest a linear or near-linear trend that is also in agreement with petrophysical predictions. We generate a new shear velocity model from the resistivity models based on petrophysical relationships. The new velocity model fits the phase velocity data, and the correlation coefficient between the shear velocity and resistivity models is increased. Much of the model can be predicted by expectations for a thermal half-space cooling model, although some regions require a combination of higher temperatures, volatiles, or partial melt. We use the petrophysical predictions to estimate the melt fraction, melt volatile content, and temperature structure of the asthenospheric anomalies. We find up to 4\% melt, with the lowest resistivities and shear velocities explained by up to 20\% water or 20\% CO2 in the melt or \~{}1\% nearly pure sulfide melt, depending on the set of assumptions used. Melt is required in punctuated anomalies over broad depth ranges, and also in channels at the base of the lithosphere. Melt in the asthenosphere is dynamic, yet persistent on geologic timescales.},
	keywords = {lithosphere asthenosphere, magnetotellurics, melt, Mid-Atlantic Ridge, Rayleigh wave tomography, small-scale convection},
	issn = {2169-9356},
	doi = {10.1029/2021JB022202},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021JB022202},
	author = {Harmon, Nicholas and Wang, Shunguo and Rychert, Catherine A. and Constable, Steven and Kendall, J. Michael}
}
@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 {leptokaropoulos_tidal_2021,
	title = {Tidal Triggering of Microseismicity at the Equatorial Mid-Atlantic Ridge, Inferred From the PI-LAB Experiment},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {126},
	number = {9},
	year = {2021},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2021JB022251},
	month = {08/2021},
	pages = {e2021JB022251},
	abstract = {The gravitational pulls from the moon and the sun result in tidal forces which influence both Earth{\textquoteright}s solid and water mass. These stresses are periodically added to the tectonic ones and may become sufficient for initiating rupture in fault systems critically close to failure. Previous research indicates correlations between increased seismicity rates and low tides for fast- and intermediate-spreading mid-ocean ridges in the Pacific Ocean. Here, we present a microseismicity data set (4,719 events) recorded by an ocean bottom seismometer deployment at the equatorial Mid-Atlantic Ridge. We show that low, as well as decreasing ocean water level, result in relatively elevated seismicity rates at higher magnitudes (lower b-values), translated into increased probabilities of stronger event occurrence at or towards low tides. Moreover, seismic bursts (enhanced activity rate clusters), occurring at rates well above the reference seismicity, are exclusively present during values of either high tidally induced extensional stresses or high extensional stress rates. Although the b-value differences are not significant enough to be conclusive, the seismicity rate variations exhibit statistical significance, supporting the previous findings for tidal triggering at low tides within normal-faulting regimes and extending the range of observations to slow-spreading ridges. Observed triggering of slip on low angle faults at low tides is predicted by Coulomb stress modeling. The triggering of slip on high angle faults observed here, is not easily explained without another factor. It may be related to the presence of a shallow magma body beneath the ridge, as supported by previous seismic imaging in the region.},
	keywords = {b-values, Coulomb stress, magnitude distribution, Mid-Atlantic Ridge, seismicity, tidal triggering},
	issn = {2169-9356},
	doi = {10.1029/2021JB022251},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021JB022251},
	author = {Leptokaropoulos, K. and Harmon, N. and Hicks, S. P. and Rychert, C. A. and Schlaphorst, D. and Kendall, J. M.}
}
@article {saikia_upper_2021,
	title = {Upper Mantle Anisotropic Shear Velocity Structure at the Equatorial Mid-Atlantic Ridge Constrained by Rayleigh Wave Group Velocity Analysis From the PI-LAB Experiment},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {22},
	number = {3},
	year = {2021},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2020GC009495},
	month = {02/2021},
	pages = {e2020GC009495},
	abstract = {The evolution of ocean lithosphere and asthenosphere are fundamental to plate tectonics, yet high resolution imaging is rare. We present shear wave velocity and azimuthal anisotropy models for the upper mantle from Rayleigh wave group velocities from local earthquake and ambient noise at 15{\textendash}40-s period recorded by the Passive Imaging of the Lithosphere Asthenosphere Boundary experiment at the equatorial Mid-Atlantic Ridge covering 0{\textendash}80-Myr-old seafloor. We find slow velocities along the ridge, with faster velocities beneath older seafloor. We image a fast lid (25{\textendash}30-km thick) beneath the ridge that increases to 50{\textendash}60 km beneath older seafloor. Punctuated, \~{}100 km wide low velocity anomalies exist off-axis. There are multiple layers of azimuthal anisotropy, including (i) a lithosphere (20{\textendash}40 km depth) characterized by strong anisotropy (4.0\%{\textendash}7.0 \%) with fast-axes that rotate from ridge subparallel toward the absolute plate motion/spreading direction at distances >60 km from the ridge, and (ii) weak anisotropy (1.0\%{\textendash}2.0\%) at >40 km depth. Our results are consistent with conductive cooling of lithosphere, although with some complexities. Thickened lithosphere beneath the ridge supports lateral conductive cooling beneath slow-spreading centers. Undulations in lithospheric thickness and slow asthenospheric velocities are consistent with small scale convection and/or partial melt. Lithospheric anisotropy can be explained by vertical flow and a contribution from either fluid or mineral filled cracks organized melt beneath the ridge and plate motion induced strain off axis. Deep azimuthal anisotropy is suggestive of upwelling beneath the ridge and three-dimensional flow possibly caused by small scale convection off-axis.},
	keywords = {asthenosphere, azimuthal anisotropy, Lithosphere, Mid-Atlantic Ridge, shear wave velocity},
	issn = {1525-2027},
	doi = {10.1029/2020GC009495},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020GC009495},
	author = {Saikia, Utpal and Rychert, Catherine and Harmon, Nicholas and Kendall, J. M.}
}
@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 {bogiatzis_source_2020,
	title = {Source Regions of Infragravity Waves Recorded at the Bottom of the Equatorial Atlantic Ocean, Using OBS of the PI-LAB Experiment},
	journal = {Journal of Geophysical Research: Oceans},
	volume = {125},
	number = {6},
	year = {2020},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2019JC015430},
	month = {05/2020},
	pages = {e2019JC015430},
	abstract = {Infragravity waves are generated along coasts, and some small fraction of their energy escapes to the open oceans and propagates with little attenuation. Due to the scarcity of deep-ocean observations of these waves, the mechanism and the extent of the infragravity waves energy leakage from the coasts remains poorly understood. Understanding the generation and pathways of infragravity wave energy is important among others for understanding the breakup of ice-shelves and the contamination of high-resolution satellite radar altimetry measurements of sea level. We examine data from 37 differential pressure gauges of Ocean Bottom Seismometers (OBS) near the equatorial mid-Atlantic ridge, deployed during the Passive Imaging of the Lithosphere-Asthenosphere Boundary (PI-LAB) experiment. We use the beamforming technique to investigate the incoming directions of infragravity waves. Next, we develop a graph-theory-based global back-projection method of noise cross-correlation function envelopes, which minimizes the effects of array geometry using an adaptive weighting scheme. This approach allows us to locate the sources of the infragravity energy. We assess our observations by comparing to a global model of infragravity wave heights. Our results reveal strong coherent energy from sources and/or reflected phases at the west coast of Africa and some sources from South America. These energy sources are in good agreement with the global infragravity wave model. In addition, we also observe infragravity waves arriving from North America during specific events that mostly occur during October{\textendash}February 2016. Finally, we find indications of waves that propagate with little attenuation, long distances through sea ice, reflecting off Antarctica.},
	keywords = {Africa, Antarctica, Atlantic Ocean, back-projection, beamforming, infragravity waves},
	issn = {2169-9291},
	doi = {10.1029/2019JC015430},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JC015430},
	author = {Bogiatzis, P. and Karamitrou, A. and Ward Neale, J. and Harmon, N. and Rychert, C. A. and Srokosz, M.}
}
@article {114,
	title = {South Atlantic Transect: Variations in Oceanic Crustal Structure at 31{\textdegree}S},
	journal = {Geochemistry Geophysics Geosystems},
	volume = {21},
	year = {2020},
	type = {Journal Article},
	abstract = {We present an analysis of geophysical data acquired along a transect of 0{\textendash}62 Ma crust located on the western flank of the Mid-Atlantic Ridge at 31{\textdegree}S; all crust was formed at the same ridge segment. Crustal thickness, constrained by five wide-angle profiles, has mean values of 5.6 km at 6.6 and 15.2 Ma, 7.0 km at 30.6 Ma, 5.5 km at 49.2 Ma, and 3.6 km at 61.2 Ma. Crustal thickness is uniform along each ridge-parallel profile (standard deviations 0.1{\textendash}0.3 km), indicating uniform along-axis magmatic accretion over lateral distances of 40{\textendash}60 km. The crustal structure of 61.2 Ma crust is not only anomalously thin compared to the other profiles but also contains regions with a linear velocity gradient from seafloor to Moho, which suggests that intense fracturing may extend to the base of the thin crust. Abyssal hill root-mean-square heights in the study region are 57{\textendash}142 m and have an inverse correlation with spreading rate. These values are lower than the average root-mean-square height of 196 m elsewhere on the southern Mid-Atlantic Ridge and indicate relatively high mantle temperatures in our study area. Unsedimented or lightly sedimented basement highs are prevalent at all ages; we argue that bottom currents scour the high topography, transporting sediment into adjacent basement lows. All drillsites planned for International Ocean Discovery Program Expeditions 390 and 393 are within 1{\textendash}10 km of unsedimented or lightly sedimented basement highs, which should facilitate fluid flow and continued geochemical exchange between crust and seafloor.},
	doi = {10.1029/2020gc009017},
	url = {https://app.dimensions.ai/details/publication/pub.1128393051},
	author = {Christeson, G. L. and Reece, R. S. and Kardell, D. A. and Estep, J. D. and Fedotova, A. and Goff, J. A.}
}
@article {Kuna2019,
	title = {Mode of slip and crust{\textendash}mantle interaction at oceanic transform faults},
	journal = {Nature Geoscience},
	volume = {12},
	number = {2},
	year = {2019},
	month = {feb},
	pages = {138{\textendash}142},
	issn = {1752-0894},
	doi = {10.1038/s41561-018-0287-1},
	url = {http://www.nature.com/articles/s41561-018-0287-1},
	author = {Kuna, V{\'a}clav M. and N{\'a}b{\v e}lek, John L. and Braunmiller, Jochen}
}
@article {fredrickson_optimizing_2019,
	title = {Optimizing Sensor Configurations for the Detection of Slow-Slip Earthquakes in Seafloor Pressure Records, Using the Cascadia Subduction Zone as a Case Study},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {124},
	number = {12},
	year = {2019},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2019JB018053},
	pages = {13504{\textendash}13531},
	abstract = {We present seafloor pressure records from the Cascadia Subduction Zone, alongside oceanographic and geophysical models, to evaluate the spatial uniformity of bottom pressure and optimize the geometry of sensor networks for resolving offshore slow-slip transients. Seafloor pressure records from 2011 to 2015 show that signal amplitudes are depth-dependent, with tidally filtered and detrended root-mean-squares of <2 cm on the abyssal plain and >6 cm on the continental shelf. This is consistent with bottom pressure predictions from circulation models and comparable to deformation amplitudes from offshore slow slip observed in other subduction zones. We show that the oceanographic component of seafloor pressure can be reduced to <=1-cm root-mean-square by differencing against a reference record from a similar depth, under restrictions that vary with depth. Instruments at 100{\textendash}250 m require depths matched within 10 m at separations of <100 km, while locations deeper than 1,400 m are broadly comparable over separations of at least 300 km. Despite the significant noise reduction from this method, no slow slip was identified in the dataset, possibly due to poor spatiotemporal instrument coverage, nonideal deployment geometry, and limited depth-matched instruments. We use forward predictions of deformation from elastic half-space models and hindcast pressure from circulation models to generate synthetic slow-slip observational records and show that a range of slip scenarios produce resolvable signals under depth-matched differencing. For future detection of offshore slow slip in Cascadia, we recommend a geometry in which instruments are deployed along isobaths to optimize corrections for oceanographic signals.},
	keywords = {Cascadia Subduction Zone, geodesy, ocean circulation, seafloor pressure, slow-slip earthquake},
	issn = {2169-9356},
	doi = {10.1029/2019JB018053},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JB018053},
	author = {Fredrickson, Erik K. and Wilcock, William S. D. and Schmidt, David A. and MacCready, Parker and Roland, Emily and Kurapov, Alexander L. and Zumberge, Mark A. and Sasagawa, Glenn S.}
}
@article {Isse2019,
	title = {Surface wave tomography for the Pacific Ocean incorporating seafloor seismic observations and plate thermal evolution},
	journal = {Earth and Planetary Science Letters},
	volume = {510},
	year = {2019},
	month = {mar},
	pages = {116{\textendash}130},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2018.12.033},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X19300032},
	author = {Isse, Takehi and Kawakatsu, Hitoshi and Yoshizawa, Kazunori and Takeo, Akiko and Shiobara, Hajime and Sugioka, Hiroko and Ito, Aki and Suetsugu, Daisuke and Reymond, Dominique}
}
@article {pavlis_unified_2019,
	title = {A unified three-dimensional model of the lithospheric structure at the subduction corner in southeast Alaska: Summary results from STEEP},
	journal = {Geosphere},
	volume = {15},
	number = {2},
	year = {2019},
	month = {jan},
	pages = {382{\textendash}406},
	abstract = {We merge structural results from the ST. Elias Erosion/tectonics Project (STEEP), other studies, and seismicity data to build a comprehensive, three-dimensional model of the lithosphere of the subduction corner in southern Alaska. The model is defined by three surfaces: (1) a top of the subducting lithosphere surface, (2) Moho surfaces, and (3) a base of subducting lithosphere surface. We model the eastern edge of the subducting lithosphere using the southern tip of the Yakutat microplate as an anchor. Kinematic reconstructions using that anchor suggest the modern Fairweather fault is likely inherited from motion of the margin in the 6{\textendash}10 Ma period. We constructed a 4D kinematic model of crustal deformation in the vicinity of Mount St. Elias. We call this model the middlebuster model because the geometry is similar to a two-sided plow with that name. The west side of the plow is the eastern limit of the Aleutian megathrust constructed from the union of constraints from STEEP seismic results and slip models of the 1979 St. Elias earthquake. The east side is inferred from geologic mapping and slip models of the 1899 Yakutat Bay earthquake sequence. The top of the plow is near the Seward Glacier, where previous studies showed near world-record exhumation rates. GPS velocity vectors show a large rotation across the syntaxis at Mount St. Elias. West of the syntaxis, faults inferred from inversion of the GPS data are above the megathrust inferred from seismic imaging. That and other evidence suggest the presence of a wedge of ductile crust that partially decouples the subducting mantle lithosphere from the upper crust in the area near the suture with the Yakutat microplate.},
	issn = {1553-040X},
	doi = {10.1130/GES01488.1},
	url = {https://doi.org/10.1130/GES01488.1},
	author = {Pavlis, Gary L. and Bauer, Mark A. and Elliott, Julie L. and Koons, Peter and Pavlis, Terry L. and Ruppert, Natalia and Ward, Kevin M. and Worthington, Lindsay L.}
}
@article {krischer_automated_2018,
	title = {Automated Large-Scale Full Seismic Waveform Inversion for North America and the North Atlantic},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {123},
	number = {7},
	year = {2018},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2017JB015289},
	pages = {5902{\textendash}5928},
	abstract = {We present a new anisotropic seismic tomography model based on a multiscale full seismic waveform inversion for crustal and upper-mantle structure from the western edge of North America across the North Atlantic and into Europe. The gradient-based inversion strategy utilizes the adjoint state method coupled with an L-BFGS quasi-Newton optimization scheme. To improve the handling of large data quantities in the context of full seismic waveform inversions, we developed a workflow framework automating the procedure across all stages, enabling us to confidently invert for waveforms from 72 events recorded at 7,737 unique stations, resulting in a total of 144,693 raypaths, most of them with three-component recordings. The final model after 20 iterations is able to explain complete waveforms including body as well as surface waves of earthquakes that were not used in the inversion down to periods of around 30 s. The model is complemented by a detailed resolution analysis in the form of 3-D distributions of direction-dependent resolution lengths.},
	keywords = {data management, full-waveform inversion, inverse problems, optimization, seismology, workflow},
	issn = {2169-9356},
	doi = {10.1029/2017JB015289},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2017JB015289},
	author = {Krischer, Lion and Fichtner, Andreas and Boehm, Christian and Igel, Heiner}
}
@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 {Lim2018,
	title = {Measurement of seismometer orientation using the tangential P-wave receiver function based on harmonic decomposition},
	journal = {Geophysical Journal International},
	volume = {212},
	number = {3},
	year = {2018},
	month = {mar},
	pages = {1747{\textendash}1765},
	issn = {0956-540X},
	doi = {10.1093/gji/ggx515},
	url = {http://academic.oup.com/gji/article/212/3/1747/4705902},
	author = {Lim, Hobin and Kim, YoungHee and Song, Teh-Ru Alex and Shen, Xuzhang}
}
@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 {Kim2018a,
	title = {Upper crustal Vp / Vs ratios at the Endeavour segment, Juan de Fuca Ridge, from joint inversion of P and S travel times: Implications for hydrothermal circulation},
	journal = {Geochemistry, Geophysics, Geosystems},
	year = {2018},
	month = {dec},
	pages = {2018GC007921},
	issn = {1525-2027},
	doi = {10.1029/2018GC007921},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GC007921},
	author = {Kim, Eunyoung and Toomey, Douglas R. and Hooft, Emilie E. E. and Wilcock, William S. D. and Weekly, Robert T. and Lee, Sang-Mook and Kim, Young Hee}
}
@article {Kim2018,
	title = {Upper crustal Vp / Vs ratios at the Endeavour segment, Juan de Fuca Ridge, from joint inversion of P and S travel times: Implications for hydrothermal circulation},
	journal = {Geochemistry, Geophysics, Geosystems},
	year = {2018},
	month = {dec},
	pages = {2018GC007921},
	issn = {1525-2027},
	doi = {10.1029/2018GC007921},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GC007921},
	author = {Kim, Eunyoung and Toomey, Douglas R. and Hooft, Emilie E. E. and Wilcock, William S. D. and Weekly, Robert T. and Lee, Sang-Mook and Kim, Young Hee}
}
@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 {Kawakatsu2017,
	title = {Seismic and Electrical Signatures of the Lithosphere{\textendash}Asthenosphere System of the Normal Oceanic Mantle},
	journal = {Annual Review of Earth and Planetary Sciences},
	volume = {45},
	number = {1},
	year = {2017},
	month = {aug},
	pages = {139{\textendash}167},
	issn = {0084-6597},
	doi = {10.1146/annurev-earth-063016-020319},
	url = {http://www.annualreviews.org/doi/10.1146/annurev-earth-063016-020319},
	author = {Kawakatsu, Hitoshi and Utada, Hisashi}
}
@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 {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 {ramsay_anisotropy_2016,
	title = {Anisotropy from SKS splitting across the Pacific-North America plate boundary offshore southern California},
	journal = {Geophysical Journal International},
	volume = {207},
	number = {1},
	year = {2016},
	month = {oct},
	pages = {244{\textendash}258},
	abstract = {SKS arrivals from ocean bottom seismometer (OBS) data from an offshore southern California deployment are analysed for shear wave splitting. The project involved 34 OBSs deployed for 12 months in a region extending up to 500 km west of the coastline into the oceanic Pacific plate. The measurement process consisted of removing the effects of anisotropy using a range of values for splitting fast directions and delay times to minimize energy along the transverse seismometer axis. Computed splitting parameters are unexpectedly similar to onland parameters, exhibiting WSW{\textendash}ENE fast polarization directions and delays between 0.8 and 1.8~s, even for oceanic plate sites. This is the first SKS splitting study to extend across the entire boundary between the North America and Pacific plates, into the oceanic part of the Pacific plate. The splitting results show that the fast direction of anisotropy on the Pacific plate does not align with absolute plate motion (APM), and they extend the trend of anisotropy in southern California an additional 500 km west, well onto the oceanic Pacific plate. We model the finite strain and anisotropy within the asthenosphere associated with density{\textendash}buoyancy driven mantle flow and the effects of APM. In the absence of plate motion effects, such buoyancy driven mantle flow would be NE-directed beneath the Pacific plate observations. The best-fit patterns of mantle flow are inferred from the tomography-based models that show primary influences from foundering higher-density zones associated with the history of subduction beneath North America. The new offshore SKS measurements, when combined with measurements onshore within the plate boundary zone, indicate that dramatic lateral variations in density-driven upper-mantle flow are required from offshore California into the plate boundary zone in California and western Basin and Range.},
	issn = {0956-540X},
	doi = {10.1093/gji/ggw271},
	url = {https://doi.org/10.1093/gji/ggw271},
	author = {Ramsay, Joseph and Kohler, Monica D. and Davis, Paul M. and Wang, Xinguo and Holt, William and Weeraratne, Dayanthie S.}
}
@article {Sahakian2016,
	title = {Geophysical Evidence for a San Andreas Subparallel Transtensional Fault along the Northeastern Shore of the Salton Sea},
	journal = {Bulletin of the Seismological Society of America},
	volume = {106},
	number = {5},
	year = {2016},
	month = {oct},
	pages = {1963{\textendash}1978},
	issn = {0037-1106},
	doi = {10.1785/0120150350},
	url = {https://pubs.geoscienceworld.org/bssa/article/106/5/1963-1978/350875},
	author = {Sahakian, Valerie and Kell, Annie and Harding, Alistair and Driscoll, Neal and Kent, Graham}
}
@article {Bowden2016,
	title = {Offshore Southern California lithospheric velocity structure from noise cross-correlation functions},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {121},
	number = {5},
	year = {2016},
	month = {may},
	pages = {3415{\textendash}3427},
	issn = {21699313},
	doi = {10.1002/2016JB012919},
	url = {http://doi.wiley.com/10.1002/2016JB012919},
	author = {Bowden, D. C. and Kohler, M. D. and Tsai, V. C. and Weeraratne, D. S.}
}
@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 {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 {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 {Reeves2015,
	title = {Lithospheric structure across the California Continental Borderland from receiver functions},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {16},
	number = {1},
	year = {2015},
	month = {jan},
	pages = {246{\textendash}266},
	issn = {15252027},
	doi = {10.1002/2014GC005617},
	url = {http://doi.wiley.com/10.1002/2014GC005617},
	author = {Reeves, Zachary and Leki{\'c}, Vedran and Schmerr, Nicholas and Kohler, Monica and Weeraratne, Dayanthie}
}
@article {Becel2015,
	title = {Origin of dipping structures in fast-spreading oceanic lower crust offshore Alaska imaged by multichannel seismic data},
	journal = {Earth and Planetary Science Letters},
	volume = {424},
	year = {2015},
	month = {aug},
	pages = {26{\textendash}37},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2015.05.016},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X15003052},
	author = {B{\'e}cel, Anne and Shillington, Donna J. and Nedimovi{\'c}, Mladen R. and Webb, Spahr C. and Kuehn, Harold}
}
@article {Karalliyadda2015,
	title = {S-wave splitting in the offshore South Island, New Zealand: Insights into plate-boundary deformation},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {16},
	number = {9},
	year = {2015},
	month = {sep},
	pages = {2829{\textendash}2847},
	issn = {15252027},
	doi = {10.1002/2015GC005882},
	url = {http://doi.wiley.com/10.1002/2015GC005882},
	author = {Karalliyadda, S. C. and Savage, M. K. and Sheehan, A. and Collins, J. and Zietlow, D. and Shelley, A.}
}
@article {van_avendonk_deep_2014,
	title = {Deep crustal structure of an arc-continent collision: Constraints from seismic traveltimes in central Taiwan and the Philippine Sea},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {119},
	number = {11},
	year = {2014},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/2014JB011327},
	pages = {8397{\textendash}8416},
	abstract = {The collision of continental crust of the Eurasian Plate with the overriding Luzon Arc in central Taiwan has led to compression, uplift, and exhumation of rocks that were originally part of the Chinese rifted margin. Though the kinematics of the fold-thrust belt on the west side of the orogen has been described in detail, the style of deformation in the lower crust beneath Taiwan is still not well understood. In addition, the fate of the Luzon Arc and Forearc in the collision is also not clear. Compressional wave arrival times from active-source and earthquake seismic data from the Taiwan Integrated Geodynamic Research program constrain the seismic velocity structure of the lithosphere along transect T5, an east-west corridor in central Taiwan. The results of our analysis indicate that the continental crust of the Eurasian margin forms a broad crustal root beneath central Taiwan, possibly with a thickness of 55 km. Compressional seismic velocities beneath the Central Range of Taiwan are as low as 5.5 km/s at 25 km depth, whereas P wave seismic velocities in the middle crust on the eastern flank of the Taiwan mountain belt average 6.5{\textendash}7.0 km/s. This suggests that the incoming sediments and upper crust of the Eurasian Plate are buried to midcrustal depth in the western flank of the orogen before they are exhumed in the Central Range. To the east, the Luzon Arc and Forearc are deformed beneath the Coastal Range of central Taiwan. Fragments of the rifted margin of the South China Sea that were accreted in the early stages of the collision form a new backstop that controls the exhumation of Eurasian strata to the west in this evolving mountain belt.},
	keywords = {arc-continent collision, earthquakes, Philippine Sea Plate, seismic refraction, Taiwan, tomography},
	issn = {2169-9356},
	doi = {10.1002/2014JB011327},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2014JB011327},
	author = {Van Avendonk, H. J. A. and Kuo-Chen, H. and McIntosh, K. D. and Lavier, L. L. and Okaya, D. A. and Wu, F. T. and Wang, C. Y. and Lee, C. S. and Liu, C. S.}
}
@article {sumy_mechanisms_2013,
	title = {The Mechanisms of Earthquakes and Faulting in the Southern Gulf of California},
	journal = {Bulletin of the Seismological Society of America},
	volume = {103},
	number = {1},
	year = {2013},
	pages = {487{\textendash}506},
	abstract = {Accurate earthquake locations and their focal mechanisms can illuminate the distribution and mode of deformation at rifted continental margins. The Pacific{\textendash}North America (Pa{\textendash}NA) plate boundary within the Gulf of California (GoC) provides an excellent opportunity to explore the evolution and kinematics of rifting, as continental extension in the north transitions to seafloor spreading in the south. From October 2005 to October 2006, an array of eight four-component ocean-bottom seismographs deployed in the GoC recorded seismicity as part of the Sea of Cortez Ocean-Bottom Array (SCOOBA) experiment. By combining the data with those from the onshore Network of Autonomously Recording Seismographs (NARS)-Baja array, we detect and locate \~{}700 earthquakes (Mw~2.2{\textendash}6.6) mainly along the northwest{\textendash}southeast-striking transform faults that delineate the plate boundary. For 36 events (Mw~3.5{\textendash}6.6) with high signal-to-noise ratio in a long-period (10{\textendash}20~s) band, we determine deviatoric moment tensors and associated double-couple focal mechanisms by regional waveform inversion. Many focal mechanisms are consistent with right-lateral strike-slip faulting along the Pa{\textendash}NA transform fault system, which suggests that the transform faults primarily accommodate seismic deformation within the gulf. In addition, we capture a swarm of events on Baja California along the right-lateral northwest{\textendash}southeast-striking Las Viboras{\textendash}El Azufre fault, which may be related to ongoing geothermal activity and volcanic deformation within the peninsula. The combination of high-resolution earthquake locations and focal mechanisms improves our understanding of the distribution of seismic deformation within the greater extensional zone in the southern GoC.Online Material: Earthquake catalog of the 695 events detected and located during our combined on-/offshore deployment of seismometers.},
	issn = {0037-1106},
	doi = {10.1785/0120120080},
	url = {https://doi.org/10.1785/0120120080},
	author = {Sumy, Danielle F. and Gaherty, James B. and Kim, Won-Young and Diehl, Tobias and Collins, John A.}
}
@article {worcester_north_2013,
	title = {The North Pacific Acoustic Laboratory deep-water acoustic propagation experiments in the Philippine Sea},
	journal = {The Journal of the Acoustical Society of America},
	volume = {134},
	number = {4},
	year = {2013},
	note = {Publisher: Acoustical Society of America},
	month = {oct},
	pages = {3359{\textendash}3375},
	abstract = {A series of experiments conducted in the Philippine Sea during 2009{\textendash}2011 investigated deep-water acoustic propagation and ambient noise in this oceanographically and geologically complex region: (i) the 2009 North Pacific Acoustic Laboratory (NPAL) Pilot Study/Engineering Test, (ii) the 2010{\textendash}2011 NPAL Philippine Sea Experiment, and (iii) the Ocean Bottom Seismometer Augmentation of the 2010{\textendash}2011 NPAL Philippine Sea Experiment. The experimental goals included (a) understanding the impacts of fronts, eddies, and internal tides on acoustic propagation, (b) determining whether acoustic methods, together with other measurements and ocean modeling, can yield estimates of the time-evolving ocean state useful for making improved acoustic predictions, (c) improving our understanding of the physics of scattering by internal waves and spice, (d) characterizing the depth dependence and temporal variability of ambient noise, and (e) understanding the relationship between the acoustic field in the water column and the seismic field in the seafloor. In these experiments, moored and ship-suspended low-frequency acoustic sources transmitted to a newly developed distributed vertical line array receiver capable of spanning the water column in the deep ocean. The acoustic transmissions and ambient noise were also recorded by a towed hydrophone array, by acoustic Seagliders, and by ocean bottom seismometers.},
	issn = {0001-4966},
	doi = {10.1121/1.4818887},
	url = {https://asa.scitation.org/doi/full/10.1121/1.4818887},
	author = {Worcester, Peter F. and Dzieciuch, Matthew A. and Mercer, James A. and Andrew, Rex K. and Dushaw, Brian D. and Baggeroer, Arthur B. and Heaney, Kevin D. and D{\textquoteright}Spain, Gerald L. and Colosi, John A. and Stephen, Ralph A. and Kemp, John N. and Howe, Bruce M. and Van Uffelen, Lora J. and Wage, Kathleen E.}
}
@article {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 {kuo-chen_three-dimensional_2012,
	title = {Three-dimensional P velocity structures of the lithosphere beneath Taiwan from the analysis of TAIGER and related seismic data sets},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {117},
	number = {B6},
	year = {2012},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2011JB009108},
	abstract = {The convergence of the Philippine Sea and the Eurasian plates in the Taiwan region led to the formation of a young collisional mountain between two subduction zones of nearly orthogonal polarities. The geological processes underlying the collision and its relation to subduction are the primary targets of TAIGER (Taiwan Integrated Geodynamic Research) project. Newly acquired passive and active sources data on land, supplemented by ocean bottom as well as permanent seismic network data, are used to derive a new 3-D tomographic velocity model. Using the 7.5 km/sec contour as a marker for crustal deformation, two trend-parallel {\textquotedblleft}roots,{\textquotedblright} one under the Central Range with a maximum depth of 55 km and the other under the Coastal Range at 40 km, are found to extend from southern to central (\~{}24{\textdegree}N) Taiwan. Between the two roots and lying approximately beneath the Longitudinal Valley, the 7.5 km/sec contour rises to 25 km depth. In the upper mantle, a high velocity zone, east-dipping and its upper surface coinciding with a Wadati-Benioff zone in the south (\~{}22.8{\textdegree}N), becomes near vertical and ill-defined in the north (\~{}23.9{\textdegree}N). The crustal deformation as defined by the {\textquotedblleft}roots{\textquotedblright} and the along-trend variations of the upper mantle structures under Taiwan provide key information for the orogeny. With the thickening of crust to 55 km or more processes such as eclogitization and delamination may come into play.},
	keywords = {mountain building, seismic tomography, Taiwan orogeny},
	issn = {2156-2202},
	doi = {10.1029/2011JB009108},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2011JB009108},
	author = {Kuo-Chen, Hao and Wu, Francis T. and Roecker, Steven W.}
}
@article {calvert_three-dimensional_2008,
	title = {Three-dimensional crustal structure of the Mariana island arc from seismic tomography},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {113},
	number = {B1},
	year = {2008},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2007JB004939},
	abstract = {A three-dimensional (3-D) seismic refraction survey was acquired over the Mariana volcanic arc at 14.5{\textendash}18.5{\textdegree}N and 145{\textendash}147{\textdegree}E. First-arrival traveltimes from this survey and from a separate 2-D survey acquired approximately perpendicular to the arc have been simultaneously inverted for a 3-D P wave velocity model using seismic tomography subject to smoothness constraints. The active arc, which initiated only 3{\textendash}4 Ma ago, has an average crustal thickness of 18 km. Approximately 40 km to the east the inactive remnant of the rifted Eocene arc has an average crustal thickness of 21 km, due primarily to a thicker lower-crustal layer with velocities of 6.5{\textendash}7.0 km s-1. Crustal production clearly varies both temporally and spatially, with some crustal layers, including the igneous fore-arc crust, varying in thickness by a factor of up to 2 along strike. Average P wave velocities within the upper crust of the modern arc are 240{\textendash}360 m s-1 lower than in the Eocene arc but are 280 m s-1 higher within the lower crust. Middle crust with velocities of 6.0{\textendash}6.5 km s-1 is best developed beneath the Eocene arc. These results suggest an evolution of arc structure with increasing age: We infer closure of fractures and porosity in the upper crust through hydrothermal circulation and a reduction in the mafic character of the middle to lower crust as a result of intracrustal differentiation. Although tonalitic rocks may predominate in the transition from upper to middle crust, the bulk of the crust is essentially basaltic.},
	keywords = {crust, Mariana arc, seismic tomography},
	issn = {2156-2202},
	doi = {10.1029/2007JB004939},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2007JB004939},
	author = {Calvert, Andrew J. and Klemperer, Simon L. and Takahashi, Narumi and Kerr, Bryan C.}
}
@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.}
}
@article {shillington_composition_2004,
	title = {Composition and structure of the central Aleutian island arc from arc-parallel wide-angle seismic data},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {5},
	number = {10},
	year = {2004},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2004GC000715},
	abstract = {New results from wide-angle seismic data collected parallel to the central Aleutian island arc require an intermediate to mafic composition for the middle crust and a mafic to ultramafic composition for the lower crust and yield lateral velocity variations that correspond to arc segmentation and trends in major element geochemistry. The 3-D ray tracing/2.5-D inversion of this sparse wide-angle data set, which incorporates independent phase interpretations and new constraints on shallow velocity structure, produces a faster and smoother result than a previously published velocity model. Middle-crustal velocities of 6.5{\textendash}7.3 km/s over depths of \~{}10{\textendash}20 km indicate an andesitic to basaltic composition. High lower-crustal velocities of 7.3{\textendash}7.7 km/s over depths of \~{}20{\textendash}35 km are interpreted as ultramafic-mafic cumulates and/or garnet granulites. The total crustal thickness is 35{\textendash}37 km. This result indicates that the Aleutian island arc has higher velocities, and thus more mafic compositions, than average continental crust, implying that significant modifications would be required for this arc to be a suitable building block for continental crust. Lateral variations in average crustal velocity (below 10 km) roughly correspond to trends in major element geochemistry of primitive (Mg \# > 0.6) lavas. The highest lower-crustal velocities (and presumably most mafic material) are detected in the center of an arc segment, between Unmak and Unalaska Islands, implying that arc segmentation exerts control over crustal composition.},
	keywords = {continental crust, crustal geophysics, island arc, major element geochemistry},
	issn = {1525-2027},
	doi = {10.1029/2004GC000715},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2004GC000715},
	author = {Shillington, Donna J. and Van Avendonk, Harm J. A. and Holbrook, W. Steven and Kelemen, Peter B. and Hornbach, Matthew J.}
}
@article {konter_seafloor_2004,
	title = {Seafloor seismic monitoring of an active submarine volcano: Local seismicity at Vailulu{\textquoteright}u Seamount, Samoa},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {5},
	number = {6},
	year = {2004},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2004GC000702},
	abstract = {We deployed five ocean bottom hydrophones (OBHs) for a 1-year seismic monitoring study of Vailulu{\textquoteright}u Seamount, the youngest and easternmost volcano in the Samoan Archipelago. Four instruments were placed on the summit crater rim at 600{\textendash}700 m water depth, and one was placed inside the crater at 1000 m water depth. An analysis of the first 45 days of records shows a very large number of seismic events, 211 of them local. These events define a steady background activity of about four seismic events per day, increasing to about 10 events per day during a week of heightened seismic activity, which peaked at 40 events during 1 day. We identified 107 earthquakes, whose arrivals could be picked on all five stations and that are likely located within the seamount, based on their similar waveforms. Two linear trends are defined by 21 of these events. These are extremely well correlated and located, first downward then upward on a steeply inclined plane that is close to the axial plane of the southeast rift as it emerges from the main summit of Vailulu{\textquoteright}u. These events resemble volcanotectonic earthquakes from subaerial volcanoes in displaying very coherent seismic waveforms and by showing systematic, narrowly defined progressions in hypocenter locations. We propose that these events reflect brittle rock failure due to magma redistribution in or near a central magma reservoir.},
	keywords = {Samoa, seismic monitoring, submarine, Vailulu{\textquoteright}u, volcanic activity, volcano},
	issn = {1525-2027},
	doi = {10.1029/2004GC000702},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2004GC000702},
	author = {Konter, J. G. and Staudigel, H. and Hart, S. R. and Shearer, P. M.}
}
