@article {wang_fluids_2024,
	title = {Fluids control along-strike variations in the Alaska megathrust slip},
	journal = {Earth and Planetary Science Letters},
	volume = {633},
	year = {2024},
	month = {may},
	pages = {118655},
	abstract = {Interseismic and coseismic slip on the subduction zone megathrust show complex along-strike variations and the controlling factors remain debated. Here we image seismic velocity anomalies to infer fluid distribution in the Alaska subduction zone (Alaska Peninsula section) with seismic tomography. The weakly locked Shumagin segment is characterized by abundant fluids on the plate interface and in the overriding plate, whereas the moderately-to-highly locked Chignik and Chirikof segments that hosted M > 8 earthquakes are relatively dry. The Kodiak segment, which was ruptured by the 1964 M9.2 Great Alaska earthquake and is presently fully locked near the trench, is characterized by a fluid-rich plate interface but a fluid-poor and inferred low-porosity overriding plate. Multiple large earthquakes have nucleated in fluid-rich regions at the plate interface. Our study highlights the important roles of fluids, particularly in the overriding plate, in controlling interseismic slip deficit and earthquake rupture. We propose that a fluid-rich overriding plate means that there has been a high sustained flux of fluids across the plate interface, which enhances the formation of clay minerals that promote fault creep.},
	keywords = {Alaska peninsula, Body-wave tomography, fluids, Megathrust earthquakes, Slip behavior, subduction zone},
	issn = {0012-821X},
	doi = {10.1016/j.epsl.2024.118655},
	url = {https://www.sciencedirect.com/science/article/pii/S0012821X24000888},
	author = {Wang, Fan and Wei, S. Shawn and Drooff, Connor and Elliott, Julie L. and Freymueller, Jeffrey T. and Ruppert, Natalia A. and Zhang, Haijiang}
}
@article {jian_hydrothermal_2024,
	title = {Hydrothermal flow and serpentinization in oceanic core complexes controlled by mafic intrusions},
	journal = {Nature Geoscience},
	year = {2024},
	note = {Publisher: Nature Publishing Group},
	pages = {1{\textendash}6},
	abstract = {Deep-sea hydrothermal systems at slow/ultraslow-spreading mid-ocean ridges are often located within ultramafic rocks that are part of oceanic core complexes. These complexes contain lower-crustal and mantle sections exhumed due to detachment faulting. Hydrothermal circulation in these environments leads to massive sulfide deposits, hydration of oceanic lithosphere and conditions resembling early Earth{\textquoteright}s life origin. However, the relationship between hydrothermal pathways in these environments and crustal and mantle lithologies, faulting, magmatism, serpentinization and alteration is poorly understood. Here we present seismic models of a Mid-Atlantic Ridge core complex and its ultramafic-hosted hydrothermal system derived from full waveform inversion of controlled-source seismic data and from local earthquake tomography. The models and derived rock properties reveal high-permeability channels within serpentinized peridotite along the flanks of the core complex. These channels converge beneath active and fossil hydrothermal fields and are diverted around mechanically strong, impermeable shallow mafic intrusions (2{\textendash}3 km wide, \textasciitilde1 km thick), causing hydrothermal outflow and the formation of massive sulfide deposits around the intrusions{\textquoteright} edges. These mafic intrusions also act as lids that limit fluid downflow{\textemdash}and thus serpentinization{\textemdash}in the centre of the core complex. Our results demonstrate that hydrothermal flow in ultramafic settings is controlled by lithology contacts, with mafic intrusions modulating hydrothermal pathways and extent of mantle serpentinization at depth.},
	keywords = {3706 Geophysics, Economic geology, Element cycles, Geodynamics, Tectonics},
	issn = {1752-0908},
	doi = {10.1038/s41561-024-01444-y},
	url = {https://www.nature.com/articles/s41561-024-01444-y},
	author = {Jian, Hanchao and Canales, J. Pablo and Dunn, Robert and Nedimovi{\'c}, Mladen R.}
}
@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 {dunn_seismic_2024,
	title = {A Seismic Tomography, Gravity, and Flexure Study of the Crust and Upper Mantle Structure Across the Hawaiian Ridge: 2. Ka{\textquoteright}ena},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {129},
	number = {2},
	year = {2024},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2023JB028118},
	month = {05/2024},
	pages = {e2023JB028118},
	abstract = {The Hawaiian Ridge, a classic intraplate volcanic chain in the Central Pacific Ocean, has long attracted researchers due to its origin, eruption patterns, and impact on lithospheric deformation. Thought to arise from pressure-release melting within a mantle plume, its mass-induced deformation of Earth{\textquoteright}s surface depends on load distribution and lithospheric properties, including elastic thickness (Te). To investigate these features, a marine geophysical campaign was carried out across the Hawaiian Ridge in 2018. Westward of the island of O{\textquoteright}ahu, a seismic tomographic image, validated by gravity data, reveals a large mass of volcanic material emplaced on the oceanic crust, flanked by an apron of volcaniclastic material filling the moat created by plate flexure. The ridge adds \~{}7 km of material to pre-existing \~{}6-km-thick oceanic crust. A high-velocity and high-density core resides within the volcanic edifice, draped by alternating lava flows and mass wasting material. Beneath the edifice, upper mantle velocities are slightly higher than that of the surrounding mantle, and there is no evidence of extensive magmatic underplating of the crust. There is \~{}3.5 km of downward deflection of the sediment-crust and crust-mantle boundaries due to flexure in response to the volcanic load. At Ka{\textquoteright}ena Ridge, the volcanic edifice{\textquoteright}s height and cross-sectional area are no more than half as large as those determined at Hawai{\textquoteright}i Island. Together, these studies confirm that volcanic loads to the west of Hawai{\textquoteright}i are largely compensated by flexure. Comparisons to the Emperor Seamount Chain confirm the Hawaiian Ridge{\textquoteright}s relatively stronger lithospheric rigidity.},
	keywords = {Hawaiian ridge, lithospheric flexure, marine gravity, plate loading, seismic tomography, volcano structure},
	issn = {2169-9356},
	doi = {10.1029/2023JB028118},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023JB028118},
	author = {Dunn, R. A. and Watts, A. B. and Xu, C. and Shillington, D. J.}
}
@article {xu_constraints_2023,
	title = {Constraints on the structure of the oceanic crust of the Tamu Massif by teleseismic P-wave coda autocorrelation},
	journal = {Frontiers in Earth Science},
	volume = {11},
	year = {2023},
	abstract = {The Tamu Massif, considered the biggest single volcano on Earth, was formed by the accumulation of enormous amounts of magma erupting to the surface. It is the largest and oldest seamount in Shatsky Rise, which is the third largest oceanic plateau on Earth. However, the formation mechanism of Tamu Massif is still controversial because evidence point to different formation hypotheses. In this paper, we applied the P-wave coda autocorrelation method and used the hydrophone waveform data acquired by the ocean bottom seismometer (OBS) deployed on Tamu Massif to constrain the oceanic crust, and these results provide new finding on the structure of the oceanic crust for Tamu Massif. We hope it can provide some implications to research the formation mechanism of Tamu Massif. These results show that some stations in Tamu Massif received reflection signals from shallower depths that are nearly parallel to the seafloor. We infer that in the shallow oceanic crust, there is a layer composed of alternating eruptions of dense, higher velocity massive lava and sparse, lower velocity pillow lava flows, which have less density and lower velocity compared to the lower oceanic crust, with a strong acoustic impedance contrasts between them and thus able to generate a reflection signal, which is observed in our autocorrelation results.},
	issn = {2296-6463},
	url = {https://www.frontiersin.org/articles/10.3389/feart.2023.1218576},
	author = {Xu, Fucong and Lu, Shaoping and Cai, Chen and Chen, Han and Dong, Shaozhe}
}
@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 {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 {dai_novel_2023,
	title = {A Novel Method to Estimate Orientations of an Ocean-Bottom Seismometer Array for Accurate Measurement of Waveform Phases and Amplitudes},
	journal = {Seismological Research Letters},
	volume = {94},
	number = {4},
	year = {2023},
	pages = {1936{\textendash}1947},
	abstract = {The misorientation of three-component seismometers restricts the application of relevant seismic experiments such as ocean-bottom seismometer (OBS) arrays. Previous orientation determination relied on an assumption that the propagation azimuth of seismic waves follows the great-circle path (GCP) azimuth. This assumption may yield systematic errors in the estimated orientation, particularly when the ray paths are bent laterally due to velocity heterogeneity in the Earth. Here, we develop a new method for unbiasedly estimating the horizontal orientations of seismic sensors and apply this method to the Blanco transform fault OBS experiment. We first retrieve the orientations relative to the propagation azimuths from the recorded Rayleigh and P waveforms, and then determine the geographic north orientations by calculating the propagation azimuths via an Eikonal-equation-based phase-tracking method that theoretically accounts for the effect of ray bending. Synthetics test validates that the phase-tracking method can retrieve unbiased propagation azimuths of seismic waves. The final results derived from Rayleigh- and P-wave polarization analyses with the respective phase-tracked propagation azimuths are more consistent and the orientation errors are smaller, indicating the robustness and accuracy of this method. Comparing the orientations from our phase-tracking method to those from the GCP assumption, the deviation can reach up to 8{\textdegree} between these two techniques in the study region. Subsequently, when orientations of the synthetics modeled from three-dimensional elastic waveform simulation are deviated according to the GCP-predicted orientations, we find nonnegligible bias in the phase and amplitude measurements that could reduce the accuracy and resolution of following inversion, which indicates the significance of our phase-tracking method in accurate orientation of OBS arrays as well as inland seismic experiments.},
	issn = {0895-0695},
	doi = {10.1785/0220220363},
	url = {https://doi.org/10.1785/0220220363},
	author = {Dai, Andy and Bao, Xueyang and Sun, Yao-Chong and Shan, Hao}
}
@article {yang_optimal_2023,
	title = {Optimal stacking of noise cross-correlation functions},
	journal = {Geophysical Journal International},
	volume = {232},
	number = {3},
	year = {2023},
	month = {mar},
	pages = {1600{\textendash}1618},
	abstract = {Cross-correlations of ambient seismic noise are widely used for seismic velocity imaging, monitoring and ground motion analyses. A typical step in analysing noise cross-correlation functions (NCFs) is stacking short-term NCFs over longer time periods to increase the signal quality. Spurious NCFs could contaminate the stack, degrade its quality and limit its use. Many methods have been developed to improve the stacking of coherent waveforms, including earthquake waveforms, receiver functions and NCFs. This study systematically evaluates and compares the performance of eight stacking methods, including arithmetic mean or linear stacking, robust stacking, selective stacking, cluster stacking, phase-weighted stacking, time{\textendash}frequency phase-weighted stacking, Nth-root stacking and averaging after applying an adaptive covariance filter. Our results demonstrate that, in most cases, all methods can retrieve clear ballistic or first arrivals. However, they yield significant differences in preserving the phase and amplitude information. This study provides a practical guide for choosing the optimal stacking method for specific research applications in ambient noise seismology. We evaluate the performance using multiple onshore and offshore seismic arrays in the Pacific Northwest region. We compare these stacking methods for NCFs calculated from raw ambient noise (referred to as Raw NCFs) and from ambient noise normalized using a one-bit clipping time normalization method (referred to as One-bit NCFs). We evaluate six metrics, including signal-to-noise ratios, phase dispersion images, convergence rate, temporal changes in the ballistic and coda waves, relative amplitude decays with distance and computational time. We show that robust stacking is the best choice for all applications (velocity tomography, monitoring and attenuation studies) using Raw NCFs. For applications using One-bit NCFs, all methods but phase-weighted and Nth-root stacking are good choices for seismic velocity tomography. Linear, robust and selective stacking methods are all equally appropriate choices when using One-bit NCFs for monitoring applications. For applications relying on accurate relative amplitudes, the linear, robust, selective and cluster stacking methods all perform well with One-bit NCFs. The evaluations in this study can be generalized to a broad range of time-series analysis that utilizes data coherence to perform ensemble stacking. Another contribution of this study is the accompanying open-source software package, StackMaster, which can be used for general purposes of time-series stacking.},
	issn = {0956-540X},
	doi = {10.1093/gji/ggac410},
	url = {https://doi.org/10.1093/gji/ggac410},
	author = {Yang, Xiaotao and Bryan, Jared and Okubo, Kurama and Jiang, Chengxin and Clements, Timothy and Denolle, Marine A}
}
@article {dai_seismic_2023,
	title = {Seismic imaging beneath Cascadia shows shallow mantle flow patterns guide lower mantle upwellings},
	journal = {Journal of Geophysical Research: Solid Earth},
	year = {2023},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2023JB026374},
	pages = {e2023JB026374},
	abstract = {The mantle transition zone plays an important role in modulating material transport between the upper mantle and the lower mantle. Constraining this transport is essential for understanding geochemical reservoirs, hydration cycles, and the evolution of the Earth. Slabs and hotspots are assumed to be the dominant locations of transport. However, the degree of material transport in other areas is debated. We apply P-to-S receiver functions to an amphibious dataset from Cascadia to image the mantle transition zone discontinuities beneath mid-ocean ridges, a hotspot, and a subduction zone. We find a mantle transition zone thinned by 10 {\textpm} 6 km beneath the ridges and by 8 {\textpm} 4 km behind the slab, closely resembling the 660 discontinuity topography. Depressions on the 410 discontinuity are smaller, 5 {\textpm} 2 km on average, focused in the north and the south and accompanied by supra-410 discontinuity melt phases. The depressions occur away from locations of uplifted 660 discontinuity, but near slow seismic velocity anomalies imaged in the upper mantle. This suggests lower mantle upwellings occur beneath ridges and slabs but stall in the transition zone, with upper mantle convection determining upward material transport from the transition zone. Therefore, upper mantle dynamics play a larger role in determining transfer than typically assumed.},
	issn = {2169-9356},
	doi = {10.1029/2023JB026374},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023JB026374},
	author = {Dai, Yuhang and Rycherrt, Catherine A. and Harmon, Nicholas}
}
@article {macgregor_seismic_2023,
	title = {A Seismic Tomography, Gravity, and Flexure Study of the Crust and Upper Mantle Structure of the Hawaiian Ridge: 1},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {128},
	number = {12},
	year = {2023},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2023JB027218},
	month = {11/2023},
	pages = {e2023JB027218},
	abstract = {The Hawaiian Ridge has long been a focus site for studying lithospheric flexure due to intraplate volcano loading, but crucial load and flexure details remain unclear. We address this problem using wide-angle seismic refraction and reflection data acquired along a \~{}535-km-long profile that intersects the ridge between the islands of Maui and Hawai{\textquoteright}i and crosses 80{\textendash}95 Myr-old lithosphere. A tomographic image constructed using travel time data of several seismic phases reveals broad flexure of Pacific oceanic crust extending up to \~{}200{\textendash}250 km either side of the Hawaiian Ridge, and vertically up to \~{}6{\textendash}7 km. The P-wave velocity structure, verified by gravity modeling, reveals that the west flank of Hawaii is comprised of extrusive lavas overlain by volcanoclastic sediments and a carbonate platform. In contrast, the H{\={a}}na Ridge, southeast of Maui, contains a high-velocity core consistent with mafic or ultramafic intrusive rocks. Magmatic underplating along the seismic line is not evident. Reflectors at the top and bottom of the pre-existing oceanic crust suggest a \~{}4.5{\textendash}6 km crustal thickness. Simple three-dimensional flexure modeling with an elastic plate thickness, Te, of 26.7 km shows that the depths to the reflectors beneath the western flank of Hawai{\textquoteright}i can be explained by volcano loading in which Maui and the older islands in the ridge contribute \~{}43\% to the flexure and the island of Hawai{\textquoteright}i \~{}51\%. Previous studies, however, revealed a higher Te beneath the eastern flank of Hawai{\textquoteright}i suggesting that isostatic compensation may not yet be complete at the youngest end of the ridge.},
	keywords = {Hawaiian ridge, lithospheric flexure, marine gravity, plate loading, seismic tomography, volcano structure},
	issn = {2169-9356},
	doi = {10.1029/2023JB027218},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023JB027218},
	author = {MacGregor, B. G. and Dunn, R. A. and Watts, A. B. and Xu, C. and Shillington, D. J.}
}
@article {262,
	title = {Slab to back-arc to arc: Fluid and melt pathways through the mantle wedge beneath the Lesser Antilles},
	journal = {Science Advances},
	volume = {9},
	year = {2023},
	month = {02/2023},
	pages = {eadd2143},
	abstract = {Volatiles expelled from subducted plates promote melting of the overlying warm mantle, feeding arc volcanism. However, debates continue over the factors controlling melt generation and transport, and how these determine the placement of volcanoes. To broaden our synoptic view of these fundamental mantle wedge processes, we image seismic attenuation beneath the Lesser Antilles arc, an end-member system that slowly subducts old, tectonized lithosphere. Punctuated anomalies with high ratios of bulk-to-shear attenuation (Qκ-1/Qμ-1 > 0.6) and VP/VS (>1.83) lie 40 km above the slab, representing expelled fluids that are retained in a cold boundary layer, transporting fluids toward the back-arc. The strongest attenuation (1000/QS ~ 20), characterizing melt in warm mantle, lies beneath the back-arc, revealing how back-arc mantle feeds arc volcanoes. Melt ponds under the upper plate and percolates toward the arc along structures from earlier back-arc spreading, demonstrating how slab dehydration, upper-plate properties, past tectonics, and resulting melt pathways collectively condition volcanism.},
	keywords = {3706 Geophysics},
	issn = {2375-2548},
	doi = {10.1126/sciadv.add2143},
	url = {https://www.science.org/doi/10.1126/sciadv.add2143},
	author = {Hicks, SP and Bie, L and Rychert, CA and Harmon, N and Goes, S and Rietbrock, A and Wei, SS and Collier, JS and Henstock, TJ and Lynch, L and Prytulak, J and Macpherson, CG and Schlaphorst, D and Wilkinson, JJ and Blundy, JD and Cooper, GF and Davy, RG and Kendall, J-M and VOILA WORKING GROUP}
}
@article {dunn_dual-level_2022,
	title = {A Dual-Level Magmatic System Beneath the East Pacific Rise, 9{\textdegree}N},
	journal = {Geophysical Research Letters},
	volume = {49},
	number = {18},
	year = {2022},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2022GL097732},
	month = {09/2022},
	pages = {e2022GL097732},
	abstract = {Data from three co-located wide-angle ocean-bottom seismograph experiments were used to make a new two-dimensional tomographic image of the East Pacific Rise at 9{\textdegree}N. The upper half of the crustal magmatic system has a different seismic structure than the lower half, presumably corresponding with differences in melt storage and crustal cooling. The upper region is narrow (\~{}4.5 km wide at 2{\textendash}3 km depth bsf) and estimated to contain higher melt fractions; the lower region broadens with depth and contains lower melt fractions. The shape of the system suggests steeply-dipping isotherms and relatively stronger hydrothermal circulation in the upper gabbroic section of the crust, with moderately flattening isotherms and less circulation in the lower gabbroic section.},
	keywords = {East Pacific Rise, seismic anisotropy, seismic tomography},
	issn = {1944-8007},
	doi = {10.1029/2022GL097732},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022GL097732},
	author = {Dunn, Robert A.}
}
@article {russell_rayleigh_2022,
	title = {Rayleigh Wave Attenuation and Amplification Measured at Ocean-Bottom Seismometer Arrays using Helmholtz Tomography},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {n/a},
	number = {n/a},
	year = {2022},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2022JB025174},
	month = {10/2022},
	pages = {e2022JB025174},
	abstract = {Shear attenuation provides insights into the physical and chemical state of the upper mantle. Yet, observations of attenuation are infrequent in the oceans, despite recent proliferation of arrays of ocean-bottom seismometers (OBS). Studies of attenuation in marine environments must overcome unique challenges associated with strong oceanographic noise at the seafloor and data loss during OBS recovery in addition to untangling the competing influences of elastic focusing, local site amplification, and anelastic attenuation on surface-wave amplitudes. We apply Helmholtz tomography to OBS data to simultaneously resolve array-averaged Rayleigh wave attenuation and maps of site amplification at periods of 20{\textendash}150 s. The approach explicitly accounts for elastic focusing and defocusing due to lateral velocity heterogeneity using wavefield curvature. We validate the approach using realistic wavefield simulations at the NoMelt Experiment and Juan de Fuca (JdF) plate, which represent endmember open-ocean and coastline-adjacent environments, respectively. Focusing corrections are successfully recovered at both OBS arrays, including at periods < 35 s at JdF where coastline effects result in strong multipathing. When applied to real data, our observations of Rayleigh wave attenuation at NoMelt and JdF revise previous estimates. At NoMelt, we observe a low attenuation lithospheric layer (Qμ>1500) overlying a highly attenuating asthenospheric layer (Qμ\~{}50{\textendash}70). At JdF, we find a broad peak in attenuation (Qμ\~{}50{\textendash}60) centered at a depth of 100{\textendash}130 km. We also report strong local site amplification at the JdF Ridge (>10\% at 31 s period), which can be used to refine models of crust and shallow mantle structure.},
	keywords = {amplification, attenuation, Helmholtz, ocean-bottom seismology, surface waves, tomography},
	issn = {2169-9356},
	doi = {10.1029/2022JB025174},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022JB025174},
	author = {Russell, Joshua B. and Dalton, Colleen A.}
}
@article {xu_seismic_2022,
	title = {A Seismic Tomography, Gravity, and Flexure Study of the Crust and Upper Mantle Structure of the Emperor Seamounts at Jimmu Guyot},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {127},
	number = {6},
	year = {2022},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2021JB023241},
	month = {05/2022},
	pages = {e2021JB023241},
	abstract = {The intraplate Hawaiian-Emperor Seamount Chain has long been considered a hotspot track generated by the motion of the Pacific plate over a deep mantle plume, and an ideal feature therefore for studies of volcanic structure, magma supply, plume-crust interaction, flexural loading, and upper mantle rheology. Despite their importance as a major component of the chain, the Emperor Seamounts have been relatively little studied. In this paper, we present the results of an active-source wide-angle reflection and refraction experiment conducted along an ocean-bottom-seismograph (OBS) line oriented perpendicular to the seamount chain, crossing Jimmu guyot. The tomographic P wave velocity model, using \~{}20,000 travel times from 26 OBSs, suggests that there is a high-velocity (>6.0 km/s) intrusive core within the edifice, and the extrusive-to-intrusive ratio is estimated to be \~{}2.5, indicating that Jimmu was built mainly by extrusive processes. The total volume for magmatic material above the top of the oceanic crust is \~{}5.3 {\texttimes} 104 km3, and the related volume flux is \~{}0.96 m3/s during the formation of Jimmu. Under volcanic loading, the \~{}5.3-km-thick oceanic crust is depressed by \~{}3.8 km over a broad region. Using the standard relationships between Vp and density, the velocity model is verified by gravity modeling, and plate flexure modeling indicates an effective elastic thickness (Te) of \~{}14 km. Finally, we find no evidence for large-scale magmatic underplating beneath the pre-existing crust.},
	keywords = {Emperor Seamounts, gravity modeling, oceanic crust, plate flexure, seamount structure, seismic tomography},
	issn = {2169-9356},
	doi = {10.1029/2021JB023241},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021JB023241},
	author = {Xu, C. and Dunn, R. A. and Watts, A. B. and Shillington, D. J. and Grevemeyer, I. and G{\'o}mez de la Pe{\~n}a, L. and Boston, B. B.}
}
@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 {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 {dobashi_improving_2021,
	title = {Improving Detectability of Seafloor Deformation From Bottom Pressure Observations Using Numerical Ocean Models},
	journal = {Frontiers in Earth Science},
	volume = {8},
	year = {2021},
	month = {01/2021},
	abstract = {We investigated ocean bottom pressure (OBP) observation data at six plate subduction zones around the Pacific Ocean. The six regions included the Hikurangi Trough, the Nankai Trough, the Japan Trench, the Aleutian Trench, the Cascadia Subduction Zone, and the Chile Trench. For the sake of improving the detectability of seafloor deformation using OBP observations, we used numerical ocean models to represent realistic oceanic variations, and subtracted them from the observed OBP data. The numerical ocean models included four ocean general circulation models (OGCMs) of HYCOM, GLORYS, ECCO2, and JCOPE2M, and a single-layer ocean model (SOM). The OGCMs are mainly driven by the wind forcing. The SOM is driven by wind and/or atmospheric pressure loading. The modeled OBP was subtracted from the observed OBP data, and root-mean-square (RMS) amplitudes of the residual OBP variations at a period of 3{\textendash}90~days were evaluated by the respective regions and by the respective numerical ocean models. The OGCMs and SOM driven by wind alone (SOMw) contributed to 5{\textendash}27\% RMS reduction in the residual OBP. When SOM driven by atmospheric pressure alone (SOMp) was added to the modeled OBP, residual RMS amplitudes were additionally reduced by 2{\textendash}15\%. This indicates that the atmospheric pressure is necessary to explain substantial amounts of observed OBP variations at the period. The residual RMS amplitudes were 1.0{\textendash}1.7~hPa when SOMp was added. The RMS reduction was relatively effective as 16{\textendash}42\% at the Hikurangi Trough, the Nankai Trough, and the Japan Trench. The residual RMS amplitudes were relatively small as 1.0{\textendash}1.1~hPa at the Nankai Trough and the Chile Trench. These results were discussed with previous studies that had identified slow slips using OBP observations. We discussed on further accurate OBP modeling, and on improving detectability of seafloor deformation using OBP observation arrays.},
	issn = {2296-6463},
	doi = {10.3389/feart.2020.598270},
	url = {https://www.frontiersin.org/articles/10.3389/feart.2020.598270},
	author = {Dobashi, Yoichiro and Inazu, Daisuke}
}
@article {doran_melt-affected_2021,
	title = {Melt-affected ocean crust and uppermost mantle near Hawaii{\textemdash}clues from ambient-noise phase velocity and seafloor compliance},
	journal = {Geophysical Journal International},
	volume = {224},
	number = {2},
	year = {2021},
	month = {jan},
	pages = {843{\textendash}857},
	abstract = {We present models of crustal and uppermost mantle structure beneath the Hawaiian Swell and surrounding region. The models were derived from ambient-noise intermediate-period Rayleigh-wave phase velocities and from seafloor compliance that were estimated from continuous seismic and pressure recordings collected during the Hawaiian Plume-Lithosphere Undersea Mantle Experiment (PLUME). We jointly inverted these data at the locations of over 50 ocean-bottom instruments, after accounting for variations in local bathymetry and sediment properties. Our results suggest that the crystalline crust is up to 15~km thick beneath the swell and up to 23~km thick closer to the islands. Anomalously thick crust extends towards the older seamounts, downstream of Hawaii. In a second region, anomalies immediately to the south of Hawaii may be associated with the leading edge of the shallow Hawaiian magma conduit. In a third region, thickened crust to the immediate west of Hawaii may be related to Cretaceous seamounts. Low seismic velocities identified in the uppermost mantle to the northeast of Hawaii may be linked to the Molokai fracture zone and may be manifest of complex non-vertical pathways of melt through the upper lithosphere. Velocity anomalies decrease in amplitude towards the surface, suggesting that melt becomes focused into conduits at depths between 20 and 40~km that escape the resolution capabilities of our data set.},
	issn = {0956-540X},
	doi = {10.1093/gji/ggaa470},
	url = {https://doi.org/10.1093/gji/ggaa470},
	author = {Doran, A K and Laske, G}
}
@article {watts_seismic_2021,
	title = {Seismic Structure, Gravity Anomalies and Flexure Along the Emperor Seamount Chain},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {126},
	number = {3},
	year = {2021},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2020JB021109},
	month = {02/2021},
	pages = {e2020JB021109},
	abstract = {The Hawaiian-Emperor seamount chain in the Pacific Ocean has provided fundamental insights into hotspot generated intraplate volcanism and the long-term strength of oceanic lithosphere. However, only a few seismic experiments to determine crustal and upper mantle structure have been carried out on the Hawaiian Ridge, and no deep imaging has ever been carried out along the Emperor seamounts. Here, we present the results of an active source seismic experiment using 29 Ocean-Bottom Seismometers (OBS) carried out along a strike profile of the seamounts in the region of Jimmu and Suiko guyots. Joint reflection and refraction tomographic inversion of the OBS data show the upper crust is highly heterogeneous with P wave velocities <4{\textendash}5 km s-1, which are attributed to extrusive lavas and clastics. In contrast, the lower crust is remarkably homogeneous with velocities of 6.5{\textendash}7.2 km s-1, which we attribute to oceanic crust and mafic intrusions. Moho is identified by a strong PmP arrival at offsets of 20{\textendash}80 km, yielding depths of 13{\textendash}16 km. The underlying mantle is generally homogeneous with velocities in the range 7.9{\textendash}8.0 km s-1. The crust and mantle velocity structure has been verified by gravity modeling. While top of oceanic crust prior to volcano loading is not recognized as a seismic or gravity discontinuity, flexural modeling reveals a \~{}5.0{\textendash}5.5 km thick preexisting oceanic crust that is overlain by a \~{}8 km thick volcanic edifice. Unlike at the Hawaiian Ridge, we find no evidence of magmatic underplating.},
	keywords = {gravity and isostasy, marine geology \& geophysics, marine seismics, oceanic hotspots and intraplate volcanism, seafloor morphology},
	issn = {2169-9356},
	doi = {10.1029/2020JB021109},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020JB021109},
	author = {Watts, A. B. and Grevemeyer, I. and Shillington, D. J. and Dunn, R. A. and Boston, B. and G{\'o}mez de la Pe{\~n}a, L.}
}
@article {becel_evidence_2020,
	title = {Evidence for a Prolonged Continental Breakup Resulting From Slow Extension Rates at the Eastern North American Volcanic Rifted Margin},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {125},
	number = {9},
	year = {2020},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2020JB020093},
	pages = {e2020JB020093},
	abstract = {When continental rifting is accompanied by localized magmatism under extensional stress, the breakup duration can be short and the continent/ocean transition sharp, as mantle melts are thought to be efficient at heating and weakening the lithosphere. This mode of rifting has been invoked for the Eastern North American Margin (ENAM) based on the existing geophysical data. Here, we present results from multichannel seismic profiles from the ENAM Community Seismic Experiment offshore North Carolina, U.S. Our survey area encompasses both the East Coast Magnetic Anomaly (ECMA) and the Blake Spur Magnetic Anomaly (BSMA), which lies 200-km farther seaward. Our prestack depth-migrated seismic images reveal major changes in the structure of the igneous crust across the BSMA. Between the ECMA and BSMA, we image a proto-oceanic domain of rough, faulted, and thin igneous crust. The roughness of this oceanic crust is similar to modern ultraslow spreading environments which involve the continued presence of a pre-existing lithospheric lid. Seaward of the BSMA the basement is smooth, and the crust is relatively thick, which is typical for Jurassic oceanic crust. Across the BSMA, we image a step up in basement and crustal root, which we interpret to represent complete lithospheric breakup and a transition to steady-state seafloor spreading in agreement with coincident refraction results. Our results would also indicate low extension rates in the final stages of rifting that may have influenced the thermal structure of the lithosphere and could explain the delay for continental breakup. All of these observations show that although continental rifting between eastern North America and northwest Africa was assisted by magmatic activity, it did not lead to rapid localization of extensional strain as previously thought.},
	keywords = {Central Atlantic opening, continental breakup, continental margin, proto-oceanic crust, steady-state seafloor spreading, volcanic rifted margin},
	issn = {2169-9356},
	doi = {10.1029/2020JB020093},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020JB020093},
	author = {B{\'e}cel, Anne and Davis, Joshua K. and Shuck, Brandon D. and Van Avendonk, Harm J. A. and Gibson, James C.}
}
@article {ma_shear_2020,
	title = {Shear attenuation and anelastic mechanisms in the central Pacific upper mantle},
	journal = {Earth and Planetary Science Letters},
	volume = {536},
	year = {2020},
	month = {04/2020},
	pages = {116148},
	abstract = {We determine the mantle attenuation (1/Qμ) structure beneath 70 Myr seafloors in the central Pacific. We use long-period (33-100 sec) Rayleigh waves recorded by the NoMelt array of broadband ocean-bottom seismometers. After the removal of tilt and compliance noise, we are able to measure Rayleigh wave phase and amplitude for 125 earthquakes. The compliance correction for ocean wave pressure on the seafloor is particularly important for improving signal-to-noise at periods longer than 55 sec. Attenuation and azimuthally anisotropic phase velocity in the study area are determined by approximating the wavefield as the interference of two plane waves. We find that the amplitude decay of Rayleigh waves across the NoMelt array can be adequately explained using a two-layer model: Qμ=1400 in the shallow layer, Qμ=110 in the deeper layer, and a transition depth at 70 km, although the sharpness of the transition is not well resolved by the Rayleigh wave data. Notably, Qμ observed in the NoMelt lithosphere is significantly higher than values in this area from global attenuation models. When compared with lithospheric Qμ measured at higher frequency (\~{}3 Hz), the frequency dependence of attenuation is very slight, revising previous interpretations. The effect of anelasticity on shear velocity (VS) is estimated from the ratio of observed velocity to the predicted anharmonic value. We use laboratory-based parameters to predict attenuation and velocity-dispersion spectra that result from the superposition of a weakly frequency dependent high-temperature background and an absorption peak. We test a large range of frequencies for the position of the absorption peak (fe) and determine, at each depth, which values of fe predict Qμ and VS that can fit the NoMelt Qμ and VS values simultaneously. We show that between depths of 60 and 80 km the seismic models require an increase in fe by at least 3-4 orders of magnitude. Under the assumption that the absorption peak is caused by elastically accommodated grain-boundary sliding, this increase in fe reflects a decrease in grain-boundary viscosity of 3-4 orders of magnitude. A likely explanation is an increase in the water content of the mantle, with the base of the dehydrated lid located at \~{}70-km depth.},
	keywords = {anelastic mechanism, oceanic lithosphere, Pacific Ocean, shear attenuation},
	issn = {0012-821X},
	doi = {10.1016/j.epsl.2020.116148},
	url = {https://www.sciencedirect.com/science/article/pii/S0012821X20300911},
	author = {Ma, Zhitu and Dalton, Colleen A. and Russell, Joshua B. and Gaherty, James B. and Hirth, Greg and Forsyth, Donald W.}
}
@article {lata_uppermost_2020,
	title = {Uppermost crustal structure across the eastern Lau spreading center from P-to-S converted waves},
	journal = {Marine Geophysical Research},
	volume = {41},
	number = {4},
	year = {2020},
	month = {11/2020},
	abstract = {P and S wave data from the L-SCAN active-source wide-angle reflection/refraction experiment are modelled to investigate upper crustal structure in the Lau backarc basin. A combination of ray tracing and finite difference numerical wavefield simulation is used to identify P and P-to-S converted seismic phases. The phases primarily arise from two shallow interfaces, one at \textasciitilde 80~m depth or less, and the other at 500{\textendash}650~m depth. The shallower interface is deeper than the sediment base, is observed across the study area, and is interpreted as a {\textquoteleft}layer 2Aa{\textquoteright} boundary, proposed to result from a rapid change in crack density. The deeper interface is interpreted as the layer 2A{\textendash}2B boundary, corresponding to a transition from lavas to sheeted dykes. Layer 2A, on average, is 150~m thicker in crust that formed at the spreading center when spreading was located near the arc (< 50~km away), as compared to when spreading was located farther away from the arc (> 70~km away). Layer 2A thickness and Vp/Vs values indicate that a thicker and more porous lava layer, dominated by basalts to basalt-andesites, cap near-arc crust, while a thinner and less-porous, mostly basaltic, volcanic layer caps the far-arc crust. These results are consistent with the waning influence of slab-derived volatiles on crustal formation as seafloor spreading moves away from the active arc.},
	keywords = {Backarc spreading center, oceanic crust, S-waves, subduction zone},
	issn = {1573-0581},
	doi = {10.1007/s11001-020-09419-5},
	url = {https://doi.org/10.1007/s11001-020-09419-5},
	author = {Lata, Charu and Dunn, Robert A.}
}
@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 {doran_calibration_2019,
	title = {Calibration of Differential Pressure Gauges Through In Situ Testing},
	journal = {Earth and Space Science},
	volume = {6},
	number = {12},
	year = {2019},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2019EA000783},
	pages = {2663{\textendash}2670},
	abstract = {Differential pressure gauges (DPGs) are a standard component of modern broadband ocean-bottom seismometer instruments and have proven useful for observing a wide range of seismic and oceanographic phenomena. However, the response function of the DPG remains poorly known, limiting our ability to recover amplitude and phase information from seafloor pressure signals with high fidelity. The sensitivity and long-period response are difficult to calibrate in the lab, as they are known to vary with temperature and pressure and perhaps between sensors of the same design. We present the results of a field experiment designed to determine empirical response functions in situ by inducing a pre-defined pressure offset on a deployed instrument. The results compare favorably with calibrations estimated independently through post-deployment data analyses. Our study demonstrates that observed response functions can deviate from the nominal response by a factor of two or greater with regards to both the sensitivity and the time constant. Incorporating calibration devices such as those described here into future deployments may prove to be a cost-effective way to improve the accuracy and utility of differential pressure data.},
	issn = {2333-5084},
	doi = {10.1029/2019EA000783},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019EA000783},
	author = {Doran, A.k. and Rapa, M. and Laske, G. and Babcock, J. and McPeak, S.}
}
@article {lynner_eastern_2019,
	title = {The Eastern North American Margin Community Seismic Experiment: An Amphibious Active- and Passive-Source Dataset},
	journal = {Seismological Research Letters},
	volume = {91},
	number = {1},
	year = {2019},
	month = {10/2019},
	pages = {533{\textendash}540},
	abstract = {The eastern North American margin community seismic experiment (ENAM-CSE) was conceived to target the ENAM Geodynamic Processes at Rifting and Subducting Margins (GeoPRISMS) primary site with a suite of both active- and passive-source seismic data that would shed light on the processes associated with rift initiation and evolution. To fully understand the ENAM, it was necessary to acquire a seismic dataset that was both amphibious, spanning the passive margin from the continental interior onto the oceanic portion of the North American plate, and multiresolution, enabling imaging of the sediments, crust, and mantle lithosphere. The ENAM-CSE datasets were collected on- and offshore of North Carolina and Virginia over a series of cruises and land-based deployments between April 2014 and June 2015. The passive-source component of the ENAM-CSE included 30 broadband ocean-bottom seismometers (OBSs) and 3 onshore broadband instruments. The broadband stations were deployed contemporaneously with those of the easternmost EarthScope Transportable Array creating a trans-margin amphibious seismic dataset. The active-source portion of the ENAM-CSE included several components: (1)~two onshore wide-angle seismic profiles where explosive shots were recorded on closely spaced geophones; (2)~four major offshore wide-angle seismic profiles acquired with an airgun source and short-period OBSs (SPOBSs), two of which were extended onland by deployments of short-period seismometers; (3)~marine multichannel seismic (MCS) data acquired along the four lines of SPOBSs and a series of other profiles along and across the margin. During the cruises, magnetic, gravity, and bathymetric data were also collected along all MCS profiles. All of the ENAM-CSE products were made publicly available shortly after acquisition, ensuring unfettered community access to this unique dataset.},
	issn = {0895-0695},
	doi = {10.1785/0220190142},
	url = {https://doi.org/10.1785/0220190142},
	author = {Lynner, Colton and J. A. Van Avendonk, Harm and B{\'e}cel, Anne and Christeson, Gail L. and Dugan, Brandon and Gaherty, James B. and Harder, Steven and Hornbach, Matthew J. and Lizarralde, Daniel and Long, Maureen D. and Magnani, M. Beatrice and Shillington, Donna J. and Aderhold, Kasey and Eilon, Zachary C. and Wagner, Lara S.}
}
@article {trehu_post-seismic_2019,
	title = {Post-seismic response of the outer accretionary prism after the 2010 Maule earthquake, Chile},
	journal = {Geosphere},
	volume = {16},
	number = {1},
	year = {2019},
	month = {dec},
	pages = {13{\textendash}32},
	abstract = {To investigate the dynamic response of the outer accretionary prism updip from the patch of greatest slip during the 2010 Mw 8.8 Maule earthquake (Chile), 10 ocean-bottom seismometers (OBSs) were deployed from May 2012 to March 2013 in a small network with an inter-instrument spacing of 7{\textendash}10 km. Nine were recovered, with four recording data from intermediate-band three-component seismometers and differential pressure gauges, and five recording data from absolute pressure gauges (APGs). All instruments were also equipped with fluid flow meters designed to detect very low rates of flow into or out of the seafloor. We present hypocenters for local earthquakes that have S-P times \&lt;17 s (i.e., within \~{}125 km of the network), with a focus on events located beneath or near the network. Most of the seismicity occurred either near the boundary between the active accretionary prism and continental basement or in the outer rise seaward of the trench. For many outer-rise earthquakes, the P and S arrivals are followed by a distinctive T-phase arrival. Very few earthquakes, and none located with hypocenters deemed {\textquotedblleft}reliable,{\textquotedblright} were located within the active accretionary prism or on the underlying plate boundary. Nonvolcanic tremor-like pulses and seafloor pressure transients (but no very-low-frequency earthquakes or fluid flow) were also detected. Many of the tremor observations are likely T-phases or reverberations due to soft seafloor sediments, although at least one episode may have originated within the accretionary prism south of the network. The transient seafloor pressure changes were observed simultaneously on three APGs located over the transition from the active prism to the continental basement and show polarity changes over short distances, suggesting a shallow source. Their duration of several hours to days is shorter than most geodetic transients observed using onshore GPS networks. The results demonstrate the need for densely spaced and large-aperture OBS networks equipped with APGs for understanding subduction zone behavior.},
	issn = {1553-040X},
	doi = {10.1130/GES02102.1},
	url = {https://doi.org/10.1130/GES02102.1},
	author = {Tr{\'e}hu, Anne M. and de Moor, Alexander and Madrid, Jos{\'e} Mieres and S{\'a}ez, Miguel and Chadwell, C. David and Ortega-Culaciati, Francisco and Ruiz, Javier and Ruiz, Sergio and Tryon, Michael D.}
}
@article {doran_seismic_2019,
	title = {Seismic Structure of Marine Sediments and Upper Oceanic Crust Surrounding Hawaii},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {124},
	number = {2},
	year = {2019},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2018JB016548},
	pages = {2038{\textendash}2056},
	abstract = {We present models of compressional and shear velocity structure of the oceanic sediments and upper crust surrounding the Hawaiian islands. The models were derived from analysis of seafloor compliance data and measurements of Ps converted phases originating at the sediment-bedrock interface. These data were estimated from continuous broadband ocean bottom seismometer acceleration and pressure records collected during the Plume-Lithosphere Undersea Mantle Experiment, an amphibious array of wideband and broadband instruments with an aperture of over 1,000 km. Our images result from a joint inversion of compliance and Ps delay data using a nonlinear inversion scheme whereby deviation from a priori constraints is minimized. In our final model, sediment thickness increases from 50 m at distal sites to over 1.5 km immediately adjacent to the islands. The sedimentary shear velocity profiles exhibit large regional variations. While sedimentary structure accounts for the majority of the compliance signal, we infer variations in shear velocity in the uppermost bedrock on the order of {\textpm}5\%. We also require relatively high values of Poisson{\textquoteright}s ratio in the uppermost crust. Lower crustal velocities are generally seen to the north and west of the islands but do not appear well correlated with the Hawaiian Swell bathymetry. A region of strong low velocity anomalies to the northeast of Hawaii may be associated with the Molokai fracture zone.},
	issn = {2169-9356},
	doi = {10.1029/2018JB016548},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018JB016548},
	author = {Doran, A. K. and Laske, G.}
}
@article {stephen_three-dimensional_2019,
	title = {Three-dimensional bottom diffraction in the North Pacific},
	journal = {The Journal of the Acoustical Society of America},
	volume = {146},
	number = {3},
	year = {2019},
	note = {Publisher: Acoustical Society of America},
	pages = {1913{\textendash}1922},
	abstract = {A significant aspect of bottom-interaction in deep water acoustic propagation, from point sources to point receivers, is the diffraction (or scattering) of energy from discrete seafloor locations along repeatable, deterministic paths in three-dimensions. These bottom-diffracted surface-reflected (BDSR) paths were first identified on the North Pacific acoustic laboratory experiment in 2004 (NPAL04) for a diffractor located on the side of a small seamount. On the adjacent deep seafloor, ambient noise and propagation in the ocean sound channel were sufficiently quiet that the BDSRs were the dominant arrival. The ocean bottom seismometer augmentation in the North Pacific (OBSANP) experiment in June{\textendash}July 2013 studied BDSRs at the NPAL04 site in more detail. BDSRs are most readily identified by the arrival time of pulses as a function of range to the receiver for a line of transmissions. The diffraction points for BDSRs occur on the relatively featureless deep seafloor as well as on the sides of small seamounts. Although the NPAL04 and OBSANP experiments had very different geometries the same diffractor location is consistent with observed arrivals in both experiments within the resolution of the analysis. On OBSANP the same location excites BDSRs for 77.5, 155, and 310 Hz transmissions.},
	issn = {0001-4966},
	doi = {10.1121/1.5125427},
	url = {https://asa.scitation.org/doi/full/10.1121/1.5125427},
	author = {Stephen, Ralph A. and Bolmer, S. Thompson and Worcester, Peter F. and Dzieciuch, Matthew A. and Udovydchenkov, Ilya A.}
}
@article {Horning2018,
	title = {Local Seismicity of the Rainbow Massif on the Mid-Atlantic Ridge},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {123},
	number = {2},
	year = {2018},
	month = {feb},
	pages = {1615{\textendash}1630},
	issn = {21699313},
	doi = {10.1002/2017JB015288},
	url = {http://doi.wiley.com/10.1002/2017JB015288},
	author = {Horning, G. and Sohn, R. A. and Canales, J. P. and Dunn, R. A.}
}
@article {lundin_magmatism_2017,
	title = {Magmatism and extension rates at rifted margins},
	journal = {Petroleum Geoscience},
	volume = {24},
	number = {4},
	year = {2017},
	month = {sep},
	pages = {379{\textendash}392},
	abstract = {Rifted margins are commonly classified as either magma-rich or magma-poor. Magma-poor margins are often implicitly related to ultraslow{\textendash}slow extension. Conversely, therefore, magma-rich margins should represent more rapid extension. Although supported by numerical modelling, these relationships are based on limited data and depend on a perhaps spurious comparison between continental margins and spreading ridges. Three case studies from the Atlantic margins are therefore presented here as a local, by no means complete, examination of this concept.Extension rates for magma-poor margins are mainly derived from offshore Iberia, while the best documented rates on magma-rich margins are probably those in the NE Atlantic. Particularly for the NE Atlantic, there is a dependence on the initial oceanic spreading rate as pre-break-up rates are very difficult to quantify. Our two southerly examples, the Central Atlantic and southern South Atlantic, are both magma-rich in parts and have been described as opening during ultraslow{\textendash}slow plate separation. Both would therefore seem to contradict the positive {\textquoteleft}rate-magmatism{\textquoteright} correlation. However, on closer examination, a wide range of initial extension rates are actually possible. This is largely due to poor constraints on break-up ages. The assumption that break-up is synchronous with flood basalt extrusion is flawed, and may have caused initial extension rates to have been significantly underestimated. Additionally, averaging between widely spaced oceanic magnetic anomalies allows for a wide range of extension rates. New, well-constrained ages and event chronologies from critical areas of conjugate margins are needed to determine whether this relationship has global validity.},
	issn = {1354-0793},
	doi = {10.1144/petgeo2016-158},
	url = {https://doi.org/10.1144/petgeo2016-158},
	author = {Lundin, Erik R. and Dor{\'e}, Anthony G. and Redfield, Thomas F.}
}
@article {Doran2017,
	title = {Ocean-Bottom Seismometer Instrument Orientations via Automated Rayleigh-Wave Arrival-Angle Measurements},
	journal = {Bulletin of the Seismological Society of America},
	volume = {107},
	number = {2},
	year = {2017},
	month = {apr},
	pages = {691{\textendash}708},
	issn = {0037-1106},
	doi = {10.1785/0120160165},
	url = {https://pubs.geoscienceworld.org/bssa/article/107/2/691-708/354158},
	author = {Doran, Adrian K. and Laske, Gabi}
}
@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 {Weirathmueller2017a,
	title = {Spatial and temporal trends in fin whale vocalizations recorded in the NE Pacific Ocean between 2003-2013},
	journal = {PLOS ONE},
	volume = {12},
	number = {10},
	year = {2017},
	month = {oct},
	pages = {e0186127},
	issn = {1932-6203},
	doi = {10.1371/journal.pone.0186127},
	url = {https://dx.plos.org/10.1371/journal.pone.0186127},
	author = {Weirathmueller, Michelle J. and Stafford, Kathleen M. and Wilcock, William S. D. and Hilmo, Rose S. and Dziak, Robert P. and Tr{\'e}hu, Anne M.},
	editor = {Li, Songhai}
}
@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 {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 {doran_infragravity_2016,
	title = {Infragravity waves and horizontal seafloor compliance},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {121},
	number = {1},
	year = {2016},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/2015JB012511},
	pages = {260{\textendash}278},
	abstract = {We report the first consistent observation of horizontal seafloor compliance induced by infragravity (IG) waves. Long-period IG ocean waves manifest themselves as broad, dominant features in ocean bottom pressure and vertical deformation spectra, but signals are rarely (if ever) identified on the horizontal components of traditional ocean bottom seismometers (OBS) due to low signal level and high current-induced tilt noise at long periods. We examine two OBS stations with shallow-buried seismometers: the Monterey Ocean Bottom Broadband site offshore California and the Ocean Seismic Network (OSN) pilot site OSN1B near Hawaii. We use nearby weather buoys to investigate the relationship between the presence of infragravity waves and environmental conditions. We find strong evidence that infragravity wave generation is primarily confined to the near-coastal environment. Additional IG source information is found by examining the directionality of passing IG waves as a function of frequency, which we analyze using the coherence between pressure and the two horizontal components. Finally, we evaluate the implications for a joint vertical and horizontal compliance inversion.},
	keywords = {horizontal infragravity energy, horizontal seafloor compliance},
	issn = {2169-9356},
	doi = {10.1002/2015JB012511},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2015JB012511},
	author = {Doran, Adrian K. and Laske, Gabi}
}
@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 {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 {Brodie2015,
	title = {Low frequency baleen whale calls detected on ocean-bottom seismometers in the Lau basin, southwest Pacific Ocean},
	journal = {The Journal of the Acoustical Society of America},
	volume = {137},
	number = {1},
	year = {2015},
	month = {jan},
	pages = {53{\textendash}62},
	issn = {0001-4966},
	doi = {10.1121/1.4904556},
	url = {http://asa.scitation.org/doi/10.1121/1.4904556},
	author = {Brodie, Dana C. and Dunn, Robert A.}
}
@article {Wei2015,
	title = {Seismic evidence of effects of water on melt transport in the Lau back-arc mantle},
	journal = {Nature},
	volume = {518},
	number = {7539},
	year = {2015},
	month = {feb},
	pages = {395{\textendash}398},
	issn = {0028-0836},
	doi = {10.1038/nature14113},
	url = {http://www.nature.com/articles/nature14113},
	author = {Wei, S. Shawn and Wiens, Douglas A. and Zha, Yang and Plank, Terry and Webb, Spahr C. and Blackman, Donna K. and Dunn, Robert A. and Conder, James A.}
}
@article {Trehu2015,
	title = {Seismicity of the Central Cascadia Continental Margin near 44.5 N: A Decadal View},
	journal = {Seismological Research Letters},
	volume = {86},
	number = {3},
	year = {2015},
	month = {may},
	pages = {819{\textendash}829},
	issn = {0895-0695},
	doi = {10.1785/0220140207},
	url = {https://pubs.geoscienceworld.org/srl/article/86/3/819-829/315628},
	author = {Trehu, A. M. and Braunmiller, J. and Davis, E.}
}
@article {Dunn2015,
	title = {Tracking stress and hydrothermal activity along the Eastern Lau Spreading Center using seismic anisotropy},
	journal = {Earth and Planetary Science Letters},
	volume = {410},
	year = {2015},
	month = {jan},
	pages = {105{\textendash}116},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2014.11.027},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X14007195},
	author = {Dunn, Robert A.}
}
@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 {dunn_crustal_2013,
	title = {Crustal construction and magma chamber properties along the Eastern Lau Spreading Center},
	journal = {Earth and Planetary Science Letters},
	volume = {371-372},
	year = {2013},
	month = {jun},
	pages = {112{\textendash}124},
	abstract = {The L-SCAN active-source seismic tomography experiment maps the crustal structure and magmatic system along a 120-km-long section of the back-arc Eastern Lau Spreading Center (ELSC), where the ridge undergoes abrupt changes in morphology and composition associated with increasing proximity to the Tofua volcanic arc. Using this dataset, we picked \textasciitilde197,000 P-wave travel times from 57 seismic airgun lines recorded at 83 ocean bottom seismograph stations, and inverted for a 3-D P-wave velocity image. The seismic images reveal a prominent, but narrow, seismic low velocity volume (LVV) located beneath all surveyed ridge segments, consistent with the high temperatures and melt of a crustal magmatic system. Crustal magmatic systems thus underlie spreading axes even where previous seismic reflection surveys did not detect magma lens reflectors, accounting for the heat source of high-temperature hydrothermal vents in these areas. The top of the LVV closely follows the ridge axis and steps across three overlapping spreading centers. As the offset of the overlap increases, the LVV becomes increasingly discontinuous across the ridge limbs. Surprisingly, the LVV is as much as twice as wide, but deeper, in the northern part of the ridge system where the crust is thinner, as compared to the LVV beneath the southern segments, where the crust is relatively thicker. The width of the LVV may be modulated by the degree of deep hydrothermal activity or temporal variations in melt supply, and thus may not correlate directly with the average melt flux as indicated by crustal thickness. Over the past 4Myr, the location of the ridge has swept across different mantle compositional domains, and the crust produced at the ridge formed a zoned pattern. The interpretation is that thick, highly porous, volcanic layers with felsic compositions cap regions of thick crust; thinner volcanic layers of basaltic composition cap regions of thinner crust. The zonal pattern indicates that the influence of slab-derived water on crustal construction has substantially decreased over time.},
	keywords = {back-arc basin, Eastern Lau Spreading Center, magma chamber, mantle melting, mid-ocean ridge, seismic tomography},
	issn = {0012-821X},
	doi = {10.1016/j.epsl.2013.04.008},
	url = {https://www.sciencedirect.com/science/article/pii/S0012821X13001891},
	author = {Dunn, Robert A. and Martinez, Fernando and Conder, James A.}
}
@article {stephen_deep_2013,
	title = {Deep seafloor arrivals in long range ocean acoustic propagation},
	journal = {The Journal of the Acoustical Society of America},
	volume = {134},
	number = {4},
	year = {2013},
	note = {Publisher: Acoustical Society of America},
	month = {oct},
	pages = {3307{\textendash}3317},
	abstract = {Ocean bottom seismometer observations at 5000 m depth during the long-range ocean acoustic propagation experiment in the North Pacific in 2004 show robust, coherent, late arrivals that are not readily explained by ocean acoustic propagation models. These {\textquotedblleft}deep seafloor{\textquotedblright} arrivals are the largest amplitude arrivals on the vertical particle velocity channel for ranges from 500 to 3200 km. The travel times for six (of 16 observed) deep seafloor arrivals correspond to the sea surface reflection of an out-of-plane diffraction from a seamount that protrudes to about 4100 m depth and is about 18 km from the receivers. This out-of-plane bottom-diffracted surface-reflected energy is observed on the deep vertical line array about 35 dB below the peak amplitude arrivals and was previously misinterpreted as in-plane bottom-reflected surface-reflected energy. The structure of these arrivals from 500 to 3200 km range is remarkably robust. The bottom-diffracted surface-reflected mechanism provides a means for acoustic signals and noise from distant sources to appear with significant strength on the deep seafloor.},
	issn = {0001-4966},
	doi = {10.1121/1.4818845},
	url = {https://asa.scitation.org/doi/full/10.1121/1.4818845},
	author = {Stephen, Ralph A. and Thompson Bolmer, S. and Udovydchenkov, Ilya A. and Worcester, Peter F. and Dzieciuch, Matthew A. and Andrew, Rex K. and Mercer, James A. and Colosi, John A. and Howe, Bruce M.}
}
@article {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 {laske_asymmetric_2011,
	title = {Asymmetric shallow mantle structure beneath the Hawaiian Swell-evidence from Rayleigh waves recorded by the PLUME network},
	journal = {Geophysical Journal International},
	volume = {187},
	number = {3},
	year = {2011},
	pages = {1725{\textendash}1742},
	abstract = {We present models of the 3-D shear velocity structure of the lithosphere and asthenosphere beneath the Hawaiian hotspot and surrounding region. The models are derived from long-period Rayleigh-wave phase velocities that were obtained from the analysis of seismic recordings collected during two year-long deployments for the Hawaiian Plume-Lithosphere Undersea Mantle Experiment. For this experiment, broad-band seismic sensors were deployed at nearly 70 seafloor sites as well as 10 sites on the Hawaiian Islands. Our seismic images result from a two-step inversion of path-averaged dispersion curves using the two-station method. The images reveal an asymmetry in shear velocity structure with respect to the island chain, most notably in the lower lithosphere at depths of 60 km and greater, and in the asthenosphere. An elongated, 100-km-wide and 300-km-long low-velocity anomaly reaches to depths of at least 140 km. At depths of 60 km and shallower, the lowest velocities are found near the northern end of the island of Hawaii. No major velocity anomalies are found to the south or southeast of Hawaii, at any depth. The low-velocity anomaly in the asthenosphere is consistent with an excess temperature of 200-250 {\textdegree}C and partial melt at the level of a few percent by volume, if we assume that compositional variations as a result of melt extraction play a minor role. We also image small-scale low-velocity anomalies within the lithosphere that may be associated with the volcanic fields surrounding the Hawaiian Islands.},
	issn = {0956-540X},
	doi = {10.1111/j.1365-246X.2011.05238.x},
	url = {https://doi.org/10.1111/j.1365-246X.2011.05238.x},
	author = {Laske, Gabi and Markee, Amanda and Orcutt, John A. and Wolfe, Cecily J. and Collins, John A. and Solomon, Sean C. and Detrick, Robert S. and Bercovici, David and Hauri, Erik H.}
}
@article {dunn_contrasting_2011,
	title = {Contrasting crustal production and rapid mantle transitions beneath back-arc ridges},
	journal = {Nature},
	volume = {469},
	number = {7329},
	year = {2011},
	note = {Number: 7329 Publisher: Nature Publishing Group},
	pages = {198{\textendash}202},
	abstract = {The Eastern Lau spreading centre, located on the Lau back-arc basin hydrothermal vent system between Fiji and Tonga, is a focus site of the Ridge 2000 research programme of the US National Science Foundation. The first large-scale seismic study of the area reveals large and abrupt across- and along-strike changes in crustal properties, implying correspondingly large discontinuities in the nature of the mantle supplying melt to the ridge axes. The authors conclude that stable, broad triangular upwelling regions, as inferred for mid-ocean ridges, cannot form near the mantle wedge corner. Instead, the observations imply a dynamic process in which the ridge upwelling zone preferentially captures water-rich low-viscosity mantle when it is near the arc. As the ridge moves away from the arc, a tipping point is reached at which the material is rapidly released, resulting in rapid changes in the character of the crust formed at the ridge.},
	keywords = {seismology},
	issn = {1476-4687},
	doi = {10.1038/nature09690},
	url = {https://www.nature.com/articles/nature09690},
	author = {Dunn, Robert A. and Martinez, Fernando}
}
@article {wolfe_mantle_2011,
	title = {Mantle P-wave velocity structure beneath the Hawaiian hotspot},
	journal = {Earth and Planetary Science Letters},
	volume = {303},
	number = {3},
	year = {2011},
	month = {mar},
	pages = {267{\textendash}280},
	abstract = {Three-dimensional images of P-wave velocity structure beneath the Hawaiian Islands, obtained from a network of seafloor and land seismometers, show an upper-mantle low-velocity anomaly that is elongated in the direction of the island chain and surrounded by a high-velocity anomaly in the shallow upper mantle that is parabolic in map view. Low velocities continue downward to the mantle transition zone between 410 and 660km depth and extend into the topmost lower mantle, although the resolution of lower mantle structure from this data set is limited. Comparisons of inversions with separate data sets at different frequencies suggest that contamination by water reverberations is not markedly biasing the P-wave imaging of mantle structure. Many aspects of the P-wave images are consistent with independent tomographic images of S-wave velocity in the region, but there are some differences in upper mantle structure between P-wave and S-wave velocities. Inversions without station terms show a southwestward shift in the location of lowest P-wave velocities in the uppermost mantle relative to the pattern for shear waves, and inversions with station terms show differences between P-wave and S-wave velocity heterogeneity in the shallow upper mantle beneath and immediately east of the island of Hawaii. Nonetheless, the combined data sets are in general agreement with the hypothesis that the Hawaiian hotspot is the result of an upwelling, high-temperature plume. The broad upper-mantle low-velocity region beneath the Hawaiian Islands may reflect the diverging {\textquotedblleft}pancake{\textquotedblright} at the top of the upwelling zone; the surrounding region of high velocities could represent a downwelling curtain; and the low-velocity anomalies southeast of Hawaii in the transition zone and topmost lower mantle are consistent with predictions of plume tilt.},
	keywords = {finite-frequency tomography, Hawaii, hotspot, mantle plume},
	issn = {0012-821X},
	doi = {10.1016/j.epsl.2011.01.004},
	url = {https://www.sciencedirect.com/science/article/pii/S0012821X11000161},
	author = {Wolfe, Cecily J. and Solomon, Sean C. and Laske, Gabi and Collins, John A. and Detrick, Robert S. and Orcutt, John A. and Bercovici, David and Hauri, Erik H.}
}
@article {van_avendonk_structure_2011,
	title = {Structure and serpentinization of the subducting Cocos plate offshore Nicaragua and Costa Rica},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {12},
	number = {6},
	year = {2011},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2011GC003592},
	abstract = {The Cocos plate experiences extensional faulting as it bends into the Middle American Trench (MAT) west of Nicaragua, which may lead to hydration of the subducting mantle. To estimate the along strike variations of volatile input from the Cocos plate into the subduction zone, we gathered marine seismic refraction data with the R/V Marcus Langseth along a 396 km long trench parallel transect offshore of Nicaragua and Costa Rica. Our inversion of crustal and mantle seismic phases shows two notable features in the deep structure of the Cocos plate: (1) Normal oceanic crust of 6 km thickness from the East Pacific Rise (EPR) lies offshore Nicaragua, but offshore central Costa Rica we find oceanic crust from the northern flank of the Cocos Nazca (CN) spreading center with more complex seismic velocity structure and a thickness of 10 km. We attribute the unusual seismic structure offshore Costa Rica to the midplate volcanism in the vicinity of the Gal{\'a}pagos hot spot. (2) A decrease in Cocos plate mantle seismic velocities from \~{}7.9 km/s offshore Nicoya Peninsula to \~{}6.9 km/s offshore central Nicaragua correlates well with the northward increase in the degree of crustal faulting outboard of the MAT. The negative seismic velocity anomaly reaches a depth of \~{}12 km beneath the Moho offshore Nicaragua, which suggests that larger amounts of water are stored deep in the subducting mantle lithosphere than previously thought. If most of the mantle low velocity zone can be interpreted as serpentinization, the amount of water stored in the Cocos plate offshore central Nicaragua may be about 2.5 times larger than offshore Nicoya Peninsula. Hydration of oceanic lithosphere at deep sea trenches may be the most important mechanism for the transfer of aqueous fluids to volcanic arcs and the deeper mantle.},
	keywords = {Central America, Cocos Plate, Gal{\'a}pagos hot spot, plate bending and faulting, seismic velocities, subduction},
	issn = {1525-2027},
	doi = {10.1029/2011GC003592},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2011GC003592},
	author = {Van Avendonk, H. J. A. and Holbrook, W. S. and Lizarralde, D. and Denyer, P.}
}
@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 {wolfe_mantle_2009,
	title = {Mantle Shear-Wave Velocity Structure Beneath the Hawaiian Hot Spot},
	journal = {Science},
	volume = {326},
	number = {5958},
	year = {2009},
	note = {Publisher: American Association for the Advancement of Science},
	month = {dec},
	pages = {1388{\textendash}1390},
	abstract = {Defining the mantle structure that lies beneath hot spots is important for revealing their depth of origin. Three-dimensional images of shear-wave velocity beneath the Hawaiian Islands, obtained from a network of sea-floor and land seismometers, show an upper-mantle low-velocity anomaly that is elongated in the direction of the island chain and surrounded by a parabola-shaped high-velocity anomaly. Low velocities continue downward to the mantle transition zone between 410 and 660 kilometers depth, a result that is in agreement with prior observations of transition-zone thinning. The inclusion of SKS observations extends the resolution downward to a depth of 1500 kilometers and reveals a several-hundred-kilometer-wide region of low velocities beneath and southeast of Hawaii. These images suggest that the Hawaiian hot spot is the result of an upwelling high-temperature plume from the lower mantle.},
	doi = {10.1126/science.1180165},
	url = {https://www.science.org/doi/full/10.1126/science.1180165},
	author = {Wolfe, Cecily J. and Solomon, Sean C. and Laske, Gabi and Collins, John A. and Detrick, Robert S. and Orcutt, John A. and Bercovici, David and Hauri, Erik H.}
}
@article {canales_crustal_2007,
	title = {Crustal structure of the Trans-Atlantic Geotraverse (TAG) segment (Mid-Atlantic Ridge, 26{\textdegree}10'N): Implications for the nature of hydrothermal circulation and detachment faulting at slow spreading ridges},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {8},
	number = {8},
	year = {2007},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2007GC001629},
	abstract = {New seismic refraction data reveal that hydrothermal circulation at the Trans-Atlantic Geotraverse (TAG) hydrothermal field on the Mid-Atlantic Ridge at 26{\textdegree}10'N is not driven by energy extracted from shallow or mid-crustal magmatic intrusions. Our results show that the TAG hydrothermal field is underlain by rocks with high seismic velocities typical of lower crustal gabbros and partially serpentinized peridotites at depth as shallow as 1 km, and we find no evidence for low seismic velocities associated with mid-crustal magma chambers. Our tomographic images support the hypothesis of Tivey et al. (2003) that the TAG field is located on the hanging wall of a detachment fault, and constrain the complex, dome-shaped subsurface geometry of the fault system. Modeling of our seismic velocity profiles indicates that the porosity of the detachment footwall increases after rotation during exhumation, which may enhance footwall cooling. However, heat extracted from the footwall is insufficient for sustaining long-term, high-temperature, hydrothermal circulation at TAG. These constraints indicate that the primary heat source for the TAG hydrothermal system must be a deep magma reservoir at or below the base of the crust.},
	keywords = {crustal structure, detachment faulting, Mid-Atlantic Ridge, slow spreading ridge, TAG hydrothermal field},
	issn = {1525-2027},
	doi = {10.1029/2007GC001629},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2007GC001629},
	author = {Canales, J. Pablo and Sohn, Robert A. and deMartin, Brian J.}
}
@article {demartin_kinematics_2007,
	title = {Kinematics and geometry of active detachment faulting beneath the Trans-Atlantic Geotraverse (TAG) hydrothermal field on the Mid-Atlantic Ridge},
	journal = {Geology},
	volume = {35},
	number = {8},
	year = {2007},
	month = {aug},
	pages = {711{\textendash}714},
	abstract = {Newly acquired seismic refraction and microearthquake data from the Trans-Atlantic Geotraverse (TAG) segment of the Mid-Atlantic Ridge at 26{\textdegree}N reveal for the first time the geometry and seismic character of an active oceanic detachment fault. Hypocenters from 19,232 microearthquakes observed during an eight month ocean bottom seismometer deployment form an \~{}15-km-long, dome-shaped fault surface that penetrates to depths \&gt;7 km below the seafloor on a steeply dipping (\~{}70{\textdegree}) interface. A tomographic model of compressional-wave velocities demonstrates that lower crustal rocks are being exhumed in the detachment footwall, which appears to roll over to a shallow dip of 20{\textdegree} {\textpm} 5{\textdegree} and become aseismic at a depth of \~{}3 km. Outboard of the detachment the exhumed lithosphere is deformed by ridge-parallel, antithetical normal faulting. Our results suggest that hydrothermal fluids at the TAG field exploit the detachment fault to extract heat from a region near the crust-mantle interface over long periods of time.},
	issn = {0091-7613},
	doi = {10.1130/G23718A.1},
	url = {https://doi.org/10.1130/G23718A.1},
	author = {deMartin, Brian J. and Sohn, Robert A. and Pablo Canales, Juan and Humphris, Susan E.}
}
@article {okaya_imaging_2003,
	title = {Imaging a plate boundar using double-sided onshore-offshore seismic profiling},
	journal = {The Leading Edge},
	volume = {22},
	number = {3},
	year = {2003},
	month = {mar},
	pages = {256{\textendash}260},
	issn = {1070-485X},
	doi = {10.1190/1.1564531},
	url = {https://doi.org/10.1190/1.1564531},
	author = {Okaya, David and Stern, Tim and Holbrook, Steve and van Avendonk, Harm and Davey, Fred and Henrys, Stuart}
}
