@article {lee_anomalous_2025,
	title = {Anomalous Sediment Consolidation and Alteration From Buried Incoming Plate Seamounts Along the Cascadia Margin},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {26},
	number = {2},
	year = {2025},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2024GC011949},
	pages = {e2024GC011949},
	abstract = {Abstract Oceanic plate seamounts are believed to play an important role in megathrust rupture at subduction zones, although consistent relationships between subducting seamounts and plate interface seismicity patterns are not found. While most studies focus on impacts linked to their topography, seamounts are also sites of heterogeneity in incoming plate sediments that may contribute to megathrust properties. Here, we characterize incoming plate sediments along the Cascadia subduction zone using new high-resolution seismic images and compressional wave (Vp) models from the CASIE21 multi-channel-seismic experiment. Nine fully-to-partially buried seamounts are identified seaward of the deformation front within a region of thick Plio-Pleistocene sediment where the Juan de Fuca plate is bending into the subduction zone. Anomalously high Vp sediment blankets two seamounts offshore Washington-Central Oregon, with wavespeeds reaching 36\% and 20\% higher than adjacent sediment. Fluid seepage and temperatures warm enough for smectite diagenesis extending to shallow depths are inferred from heat flow studies and we attribute Vp anomalies to sediment cementation linked primarily to smectite dehydration. Signatures of fluid seepage above seamounts are also identified offshore Vancouver Island, but anomalously low Vp sediment below distinct reverse polarity reflections are found, indicating trapped fluids, and cooler basement temperatures are inferred. Landward of one seamount, a zone of enhanced sediment compaction is found, consistent with the predicted stress modulating effects of seamount subduction. These new findings of variations in sediment diagenesis and strength around seamounts prior to subduction may contribute to the diverse megathrust frictional properties and seismicity patterns evident at subducting seamounts.},
	doi = {https://doi.org/10.1029/2024GC011949},
	author = {Lee, Michelle K. and Carbotte, Suzanne M. and Han, Shuoshuo and Shuck, Brandon and Gurun, Pinar and Boston, Brian and Nedimovic, Mladen and Tobin, Harold and Norvell, Ben and Spinelli, Glenn}
}
@article {ashraf_high-resolution_2025,
	title = {A High-Resolution 3-D P-Wave Velocity Structure of the South-Central Cascadia Subduction Zone From Wide-Angle Shore-Crossing Seismic Refraction Data},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {130},
	number = {2},
	year = {2025},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2024JB029525},
	pages = {e2024JB029525},
	abstract = {Abstract This study addresses a significant gap in understanding the features of the south-central Cascadia subduction zone, a region characterized by complex geologic, tectonic, and seismic transitions both offshore and onshore. Unlike other segments along this margin, this area lacks a 3-D velocity model to delineate its structural and geological features on a fine scale. To address this void, we developed a high-resolution 3-D P-wave velocity model using active source seismic data from ship-borne seismic shots recorded on temporary and permanent onshore seismic stations and ocean-bottom seismometers. Our model shows velocity variations across the region with distinct velocity-depth profiles for the Siletz, Franciscan, and Klamath terranes in the overlying plate. We identified seaward dipping high-velocity static backstops associated with the Siletz and Klamath terranes, situated near the shoreline and further inland, respectively. Regions of reduced crustal velocity are associated with crustal faults. Moreover, there is significant along-strike depth variation in the subducting slab, which is about 4 km deeper near the thick, dense Siletz terrane and becomes shallower near the predominantly less-dense Franciscan terrane. This highlights a sudden tectonic and geologic transition at the southern boundary of the Siletz terrane. Our velocity model also indicates slightly increased hydration, though still minimal, in both the oceanic crust and the upper mantle of the subducting plate compared to other parts of the margin.},
	doi = {https://doi.org/10.1029/2024JB029525},
	author = {Ashraf, Asif and Hooft, Emilie E. E. and Toomey, Douglas R. and Tr{\'e}hu, Anne M. and Nolan, Sarah and Wirth, Erin A. and Ward, Kevin M.}
}
@article {niklasson_seafloor_2025,
	title = {Seafloor Seismic Noise Patterns Across the Pacific Basin},
	journal = {Seismological Research Letters},
	volume = {96},
	number = {2A},
	year = {2025},
	month = {feb},
	pages = {772{\textendash}783},
	abstract = {Seismic hazard monitoring and global tomography efforts are improved by recording signals at a variety of distances and azimuths to maximize subsurface sampling. Although seismic networks provide good to excellent coverage on land, seafloor stations are still sparse. Inclusion of ocean-based data would greatly improve the global coverage of seismic networks, but the use of seafloor seismic data to complement land-based detection and characterization of events is complicated by the generally much higher ambient noise level in the ocean compared to that observed on land. This noise is driven primarily by sea surface waves and tides, but how seismic noise levels vary with location in the oceans is not well described. Here, we analyze the relationship between ocean surface wave height and seismic noise in the 0.4{\textendash}4~Hz frequency band at ocean-bottom seismometer deployments across the Pacific basin. We find that a noise-to-responsiveness ratio (NRR){\textemdash}the median noise level at a station divided by its sea surface wave height responsiveness{\textemdash}correlates negatively with detection success for large teleseismic earthquakes. Stations that are close to land, with relatively shallow ocean and low wind speed, often have lower NRR than open-ocean stations, but the connection between geographic location and earthquake detection success is imperfect.},
	issn = {0895-0695},
	doi = {10.1785/0220240361},
	url = {https://doi.org/10.1785/0220240361},
	author = {Niklasson, Siobhan and Rowe, Charlotte and Bilek, Susan}
}
@article {gase_toques_2025,
	title = {TOQUES: An Ocean-Bottom Seismometer Dataset on the Central Queen Charlotte Fault, Southeast Alaska},
	journal = {Seismological Research Letters},
	year = {2025},
	month = {mar},
	abstract = {Plate boundaries in the oceans are often poorly monitored. Though typically less remote than the deep sea, shallow marine environments with seafloor depths \&lt;0.5~km can be especially challenging for seismic experiments due to natural and anthropogenic hazards and noise sources that can affect instrument survival and data quality. The Queen Charlotte fault (QCF) is part of a transform plate boundary that follows the continental shelf of the Alaska Panhandle and central British Columbia. This fault system accommodates dextral slip between the Pacific and North American plates and has hosted several historic Mw \&gt; 7 earthquakes. In August 2021, we deployed 28 broadband ocean-bottom seismometers (OBSs) along the central QCF for the {\textquotedblleft}Transform Obliquity along the Queen Charlotte Fault and Earthquake Study{\textquotedblright} (TOQUES) to investigate fault architecture and local seismicity. Deployment depths varied between 0.2 and 2.5~km below sea level, with half of the instruments deployed in shallow water (\&lt;0.5~km depth). We describe the scientific motivations for the TOQUES broadband OBS array, present data metrics, and discuss factors that influence data quality and instrument survival. We show that many opportunities exist for scientific study of shallow marine environments and the solid earth. Despite concerns that shallow water was responsible for the risk of data or instrument loss, direct relationships between instrument success and water depth are inconclusive. Rather, instrument success may be more related to the ability of different instrument designs to withstand shallow-water conditions.},
	issn = {0895-0695},
	doi = {10.1785/0220240380},
	url = {https://doi.org/10.1785/0220240380},
	author = {Gase, Andrew C. and Roland, Emily C. and Worthington, Lindsay L. and Walton, Maureen A. L. and Bostock, Michael G. and Nedimovi{\'c}, Mladen R. and Collins, John A. and Brandl, Collin C. and Jaye Oliva, Sarah and Sun, Tianhaozhe}
}
@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 {niksejel_obstransformer_2024,
	title = {OBSTransformer: A Deep-Learning Seismic Phase Picker for OBS Data Using Automated Labelling and Transfer Learning},
	journal = {Geophysical Journal International},
	year = {2024},
	pages = {ggae049},
	abstract = {Accurate seismic phase detection and onset picking are fundamental to seismological studies. Supervised deep-learning phase pickers have shown promise with excellent performance on land seismic data. Although it may be acceptable to apply them to OBS (Ocean Bottom Seismometer) data that are indispensable for studying ocean regions, they suffer from a significant performance drop. In this study, we develop a generalised transfer-learned OBS phase picker {\textendash} OBSTransformer, based on automated labelling and transfer learning. First, we compile a comprehensive dataset of catalogued earthquakes recorded by 423 OBSs from 11 temporary deployments worldwide. Through automated processes, we label the P and S phases of these earthquakes by analysing the consistency of at least three arrivals from four widely used machine learning pickers (EQTransformer, PhaseNet, Generalized Phase Detection, and PickNet), as well as the AIC (Akaike Information Criterion) picker. This results in an inclusive OBS dataset containing \~{}36,000 earthquake samples. Subsequently, we employ this dataset for transfer learning and utilize a well-trained land machine learning model {\textendash} EQTransformer as our base model. Moreover, we extract 25,000 OBS noise samples from the same OBS networks using the Kurtosis method, which are then used for model training alongside the labelled earthquake samples. Using three groups of test datasets at sub-global, regional, and local scales, we demonstrate that OBSTransformer outperforms EQTransformer. Particularly, the P and S recall rates at large distances (\&gt;200 km) are increased by 68\% and 76\%, respectively. Our extensive tests and comparisons demonstrate that OBSTransformer is less dependent on the detection/picking thresholds and is more robust to noise levels.},
	issn = {0956-540X},
	doi = {10.1093/gji/ggae049},
	url = {https://doi.org/10.1093/gji/ggae049},
	author = {Niksejel, Alireza and Zhang, Miao}
}
@article {zang_reciprocity-based_2024,
	title = {A Reciprocity-Based Efficient Method for Improved Source Parameter Estimation of Submarine Earthquakes With Hybrid 3-D Teleseismic Green{\textquoteright}s Functions},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {129},
	number = {5},
	year = {2024},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2023JB028174},
	month = {05/2024},
	pages = {e2023JB028174},
	abstract = {Accurate source parameters of global submarine earthquakes are essential for understanding earthquake mechanics and tectonic dynamics. Previous studies have demonstrated that teleseismic P coda waveform complexities due to near-source 3-D structures are highly sensitive to source parameters of marine earthquakes. Leveraging these sensitivities, we can improve the accuracy of source parameter inversion compared to traditional 1-D methods. However, modeling these intricate 3-D effects poses significant computational challenges. To address this issue, we propose a novel reciprocity-based hybrid method for computing 3-D teleseismic Green{\textquoteright}s functions. Based on this method, we develop a grid-search inversion workflow for determining reliable source parameters of moderate-sized submarine earthquakes. The method is tested and proven on five Mw5+ earthquakes at the Blanco oceanic transform fault (OTF) with ground truth locations resolved by a local ocean bottom seismometer array, using ambient noise correlation and surface-wave relocation techniques. Our results show that fitting P coda waveforms through 3-D Green{\textquoteright}s functions can effectively improve the source location accuracy, especially for the centroid depth. Our improved centroid depths indicate that all the five Mw5+ earthquakes on the Blanco transform fault ruptured mainly above the depth of 600{\textdegree}C isotherm predicted by the half-space cooling model. This finding aligns with the hypothesis that the rupture zone of large earthquakes at OTFs is confined by the 600{\textdegree}C isotherm. However, it is noted that the Blanco transform fault serves as a case study. Our 3-D source inversion method offers a promising tool for systematically investigating global oceanic earthquakes using teleseismic waves.},
	keywords = {14 Life Below Water, 3-D teleseismic Green{\textquoteright}s function, Blanco transform fault, improved source parameters, moderate-sized submarine earthquakes, reciprocity, SEM-DSM method},
	issn = {2169-9356},
	doi = {10.1029/2023JB028174},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023JB028174},
	author = {Zang, Chong and Wu, Wenbo and Ni, Sidao and Xu, Min}
}
@article {carbotte_subducting_2024,
	title = {Subducting plate structure and megathrust morphology from deep seismic imaging linked to earthquake rupture segmentation at Cascadia},
	journal = {Science Advances},
	volume = {10},
	number = {23},
	year = {2024},
	note = {_eprint: https://www.science.org/doi/pdf/10.1126/sciadv.adl3198},
	pages = {eadl3198},
	abstract = {The origin of rupture segmentation along subduction zone megathrusts and linkages to the structural evolution of the subduction zone are poorly understood. Here, regional-scale seismic imaging of the Cascadia margin is used to characterize the megathrust spanning 900 km from Vancouver Island to the California border, across the seismogenic zone to a few tens of kilometers from the coast. Discrete domains in lower plate geometry and sediment underthrusting are identified, not evident in prior regional plate models, which align with changes in lithology and structure of the upper plate and interpreted paleo-rupture patches. Strike-slip faults in the lower plate associated with oblique subduction mark boundaries between regions of distinct lower plate geometry. Their formation may be linked to changes in upper plate structure across long-lived upper plate faults. The Juan de Fuca plate is fragmenting within the seismogenic zone at Cascadia as the young plate bends beneath the heterogeneous upper plate resulting in structural domains that coincide with paleo-rupture segmentation. A fragmented lower plate in the Cascadia seismogenic zone bounds structural domains linked to paleo-rupture segmentation.},
	doi = {10.1126/sciadv.adl3198},
	author = {Carbotte, Suzanne M. and Boston, Brian and Han, Shuoshuo and Shuck, Brandon and Beeson, Jeffrey and Canales, J. Pablo and Tobin, Harold and Miller, Nathan and Nedimovic, Mladen and Tr{\'e}hu, Anne and Lee, Michelle and Lucas, Madelaine and Jian, Hanchao and Jiang, Danqi and Moser, Liam and Anderson, Chris and Judd, Darren and Fernandez, Jaime and Campbell, Chuck and Goswami, Antara and Gahlawat, Rajendra}
}
@article {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 {chrapkiewicz_magma_2022,
	title = {Magma Chamber Detected Beneath an Arc Volcano With Full-Waveform Inversion of Active-Source Seismic Data},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {23},
	number = {11},
	year = {2022},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2022GC010475},
	month = {10/2022},
	pages = {e2022GC010475},
	abstract = {Arc volcanoes are underlain by complex systems of molten-rock reservoirs ranging from melt-poor mush zones to melt-rich magma chambers. Petrological and satellite data indicate that eruptible magma chambers form in the topmost few kilometres of the crust. However, very few chambers have ever been definitively located, suggesting that most are too short-lived or too small to be imaged, which has direct implications for hazard assessment and modeling of magma differentiation. Here we use a high-resolution technology based on inverting full seismic waveforms to image a small, high-melt-fraction magma chamber that was not detected with standard seismic tomography. The melt reservoir extends from \~{}2 to at least 4 km below sea level (b.s.l.) at Kolumbo{\textemdash}a submarine volcano near Santorini, Greece. The chamber coincides with the termination point of the recent earthquake swarms and may be a missing link between a deeper melt reservoir and the high-temperature hydrothermal system venting at the crater floor. The chamber poses a serious hazard as it could produce a highly explosive, tsunamigenic eruption in the near future. Our results suggest that similar reservoirs (relatively small but high-melt-fraction) may have gone undetected at other active volcanoes, challenging the existing eruption forecasts and reactive-flow models of magma differentiation.},
	keywords = {full-waveform inversion, Kolumbo volcano, magma chamber, magmatic system, Santorini volcanic field, volcano tomography},
	issn = {1525-2027},
	doi = {10.1029/2022GC010475},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022GC010475},
	author = {Chrapkiewicz, K. and Paulatto, M. and Heath, B. A. and Hooft, E. E. E. and Nomikou, P. and Papazachos, C. B. and Schmid, F. and Toomey, D. R. and Warner, M. R. and Morgan, J. V.}
}
@article {boulahanis_structure_2022,
	title = {Structure and Evolution of Northern Juan de Fuca Crust and Uppermost Mantle Over the Last 8 Ma From an Active-Source Seismic Tomography Study},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {127},
	number = {9},
	year = {2022},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2022JB023987},
	month = {08/2022},
	pages = {e2022JB023987},
	abstract = {We present results from a two-dimensional wide-angle controlled source seismic transect designed to characterize the velocity structure of the oceanic crust and uppermost mantle spanning the northern Juan de Fuca (JdF) plate from near Endeavor ridge to the Cascadia margin. Reflection and refraction travel time inversion is used to derive a tomographic Vp model of sediments, crust, and upper mantle. Velocity model results are compared to baseline reference Vp values for unaltered crustal and upper mantle rocks at temperatures assuming plate cooling. Effective medium theory is used to infer the degree of hydration of the crust and mantle. Results indicate a somewhat fractured and hydrated upper crust (<=2.5 wt\% water), a near dry lower crust (<=0.7 wt\%) and upper mantle (<=0.5 wt\%) west of the deformation front, and an \~{}75 km wide region of modestly lower velocity in the mid-plate. Comparison with prior results from a complementary transect offshore Oregon indicates significant differences in Vp of the upper crust, with lower Vp-inferred porosity along most of the Washington transects that may reflect different extents of fault-related alteration and sediment burial histories. Approaching the deformation front, Washington transect Vp structure indicates dryer conditions than offshore Oregon, consistent with differences in extent of subduction bend faulting found in reflection imaging studies. On both transects, quasi-abrupt changes in plate properties at ages of 8, 6, and 3.4/4 Ma are found. Distinct crustal accretion modes are recognized, aligning with changes in JdF plate motion and recent history of Cobb-Eickelberg hotspot influence on crustal accretion at the JdF ridge.},
	issn = {2169-9356},
	doi = {10.1029/2022JB023987},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022JB023987},
	author = {Boulahanis, Bridgit and Carbotte, Suzanne M. and Canales, Juan Pablo and Han, Shuoshuo and Nedimovi{\'c}, Mladen R.}
}
@article {nakai_near_2021,
	title = {Near Trench 3D Seismic Attenuation Offshore Northern Hikurangi Subduction Margin, North Island, New Zealand},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {126},
	number = {3},
	year = {2021},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2020JB020810},
	month = {02/2021},
	pages = {e2020JB020810},
	abstract = {We image seismic attenuation near the Hikurangi trench offshore New Zealand, using ocean bottom and land-based seismometers, revealing high attenuation above a recurring shallow slow-slip event and within the subducting Hikurangi Plateau. The Hikurangi subduction margin east of the North Island, New Zealand is the site of frequent shallow slow slip events. Overpressured fluids are hypothesized to lead to slow slip at shallow depths close to the oceanic trench. Seismic attenuation, energy loss of seismic waves, can be used to detect high temperatures, melt, the presence of fluids, and fractures. We use local earthquake P- and S-waves from 180 earthquakes to invert for t*, and subsequently invert for Qp and Qs, offshore the North Island directly above the area of slow slip. We image Qp and Qs to \~{}25 km depth, increasing resolution of previously identified coastal low Q (100{\textendash}300), and finding a new region of even higher attenuation (Qp and Qs < 50{\textendash}100) directly above the shallow slow slip event of 2014{\textendash}2015, beneath the offshore seismic array. This highest attenuation is downdip of a subducting seamount, and is spatially correlated with a high seismic reflectivity zone and Vp/Vs > 1.85, all of which provide evidence for the presence of fluids. The Qp and Qs is low at the trench (<50{\textendash}100) and in the subducting plate (100{\textendash}200), suggesting that seismic wave scattering due to faults, fractures, and the inherent heterogeneous composition of the Hikurangi Plateau, a large igneous province, plays a role in seismic attenuation.},
	keywords = {fluids, seismic attenuation, subduction zone},
	issn = {2169-9356},
	doi = {10.1029/2020JB020810},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020JB020810},
	author = {Nakai, Jenny S. and Sheehan, Anne F. and Abercrombie, Rachel E. and Eberhart-Phillips, Donna}
}
@article {heath_relationship_2021,
	title = {Relationship Between Active Faulting/Fracturing and Magmatism Around Santorini: Seismic Anisotropy From an Active Source Tomography Experiment},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {126},
	number = {8},
	year = {2021},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2021JB021898},
	month = {07/2021},
	pages = {e2021JB021898},
	abstract = {In extending volcanic arcs such as the Aegean, tectonic processes exert a significant control on magmatism. Spanning scales from 1 to 10s of km, volcanic vents, edifices, and eruptive centers follow the orientation of, and are located near, fault zones. Whether this tectonic control on magmatism results from individual faults/fractures weakening the crust or because regional stresses control magma input into the crust is debated. Here we investigate the scales of tectonic and magmatic interactions, specifically focusing on the role of local-scale (<10 km) faults/fractures in controlling magmatism. We infer local-scale fault/fracture orientations from anisotropic active-source P-wave travel-time tomography to investigate tectonic and magmatic interactions in the upper crust of Santorini Volcano, Greece, and the actively deforming region to the east. We use the anisotropy magnitude and seismic velocity reduction to model the relative distribution of both consistently oriented and randomly oriented faults/fractures. Our results show that oriented faulting/fracturing resulting from regional-scale (>10 km) tectonic stresses is distributed broadly across the region at 2{\textendash}3 km depth, approximately paralleling volcanic/magmatic features. On a local-scale, magmatism is neither localized in areas of higher oriented fault/fracture density, nor is it accommodating enough extensional strain to inhibit oriented faulting/fracturing of host rock. The alignment of magmatic features shows strong tectonic control despite the lack of correlation with local oriented fault/fracture density. These results suggest that magmatic processes are strongly influenced by regional-scale, not local-scale, tectonic processes. We infer regional processes have a greater impact on magmatism than local features due to their greater effect at depth.},
	keywords = {anisotropy, faulting, magmatism, seismology, tectonism, tectono-magmatism},
	issn = {2169-9356},
	doi = {10.1029/2021JB021898},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021JB021898},
	author = {Heath, B. A. and Hooft, E. E. E. and Toomey, D. R. and Paulatto, M. and Papazachos, C. B. and Nomikou, P. and Morgan, J. V.}
}
@article {kuna_seismic_2021,
	title = {Seismic crustal imaging using fin whale songs},
	journal = {Science},
	volume = {371},
	number = {6530},
	year = {2021},
	note = {Publisher: American Association for the Advancement of Science},
	month = {02/2021},
	pages = {731{\textendash}735},
	abstract = {Fin whale calls are among the strongest animal vocalizations that are detectable over great distances in the oceans. We analyze fin whale songs recorded at ocean-bottom seismometers in the northeast Pacific Ocean and show that in addition to the waterborne signal, the song recordings also contain signals reflected and refracted from crustal interfaces beneath the stations. With these data, we constrain the thickness and seismic velocity of the oceanic sediment and basaltic basement and the P-wave velocity of the gabbroic lower crust beneath and around the ocean bottom seismic stations. The abundant and globally available fin whale calls may be used to complement seismic studies in situations where conventional air-gun surveys are not available.},
	doi = {10.1126/science.abf3962},
	url = {https://www.science.org/doi/10.1126/science.abf3962},
	author = {Kuna, V{\'a}clav M. and N{\'a}b{\v e}lek, John L.}
}
@article {McVey2020,
	title = {Magma accumulation beneath Santorini volcano, Greece, from P-wave tomography},
	journal = {Geology},
	volume = {48},
	number = {3},
	year = {2020},
	month = {mar},
	pages = {231{\textendash}235},
	abstract = {Despite multidisciplinary evidence for crustal magma accumulation below Santorini volcano, Greece, the structure and melt content of the shallow magmatic system remain poorly constrained. We use three-dimensional (3-D) velocity models from tomographic inversions of active-source seismic P-wave travel times to identify a pronounced low-velocity anomaly ({\textendash}21\%) from 2.8 km to 5 km depth localized below the northern caldera basin. This anomaly is consistent with depth estimates of pre-eruptive storage and a recent inflation episode, supporting the interpretation of a shallow magma body that causes seismic attenuation and ray bending. A suite of synthetic tests shows that the geometry is well recovered while a range of melt contents (4\%{\textendash}13\% to fully molten) are allowable. A thin mush region (2\%{\textendash}7\% to 3\%{\textendash}10\% melt) extends from the main magma body toward the northeast, observed as low velocities confined by tectono-magmatic lineaments. This anomaly terminates northwest of Kolumbo; little to no melt underlies the seamount from 3 to 5 km depth. These structural constraints suggest that crustal extension and edifice loads control the geometry of magma accumulation and emphasize that the shallow crust remains conducive to melt storage shortly after a caldera-forming eruption.},
	issn = {0091-7613},
	doi = {10.1130/G47127.1},
	url = {https://pubs.geoscienceworld.org/gsa/geology/article/48/3/231/579527/Magma-accumulation-beneath-Santorini-volcano},
	author = {McVey, B.G. and Hooft, E.E.E. and Heath, B.A. and Toomey, D.R. and Paulatto, M. and Morgan, J.V. and Nomikou, P. and Papazachos, C.B.}
}
@article {bogiatzis_source_2020,
	title = {Source Regions of Infragravity Waves Recorded at the Bottom of the Equatorial Atlantic Ocean, Using OBS of the PI-LAB Experiment},
	journal = {Journal of Geophysical Research: Oceans},
	volume = {125},
	number = {6},
	year = {2020},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2019JC015430},
	month = {05/2020},
	pages = {e2019JC015430},
	abstract = {Infragravity waves are generated along coasts, and some small fraction of their energy escapes to the open oceans and propagates with little attenuation. Due to the scarcity of deep-ocean observations of these waves, the mechanism and the extent of the infragravity waves energy leakage from the coasts remains poorly understood. Understanding the generation and pathways of infragravity wave energy is important among others for understanding the breakup of ice-shelves and the contamination of high-resolution satellite radar altimetry measurements of sea level. We examine data from 37 differential pressure gauges of Ocean Bottom Seismometers (OBS) near the equatorial mid-Atlantic ridge, deployed during the Passive Imaging of the Lithosphere-Asthenosphere Boundary (PI-LAB) experiment. We use the beamforming technique to investigate the incoming directions of infragravity waves. Next, we develop a graph-theory-based global back-projection method of noise cross-correlation function envelopes, which minimizes the effects of array geometry using an adaptive weighting scheme. This approach allows us to locate the sources of the infragravity energy. We assess our observations by comparing to a global model of infragravity wave heights. Our results reveal strong coherent energy from sources and/or reflected phases at the west coast of Africa and some sources from South America. These energy sources are in good agreement with the global infragravity wave model. In addition, we also observe infragravity waves arriving from North America during specific events that mostly occur during October{\textendash}February 2016. Finally, we find indications of waves that propagate with little attenuation, long distances through sea ice, reflecting off Antarctica.},
	keywords = {Africa, Antarctica, Atlantic Ocean, back-projection, beamforming, infragravity waves},
	issn = {2169-9291},
	doi = {10.1029/2019JC015430},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JC015430},
	author = {Bogiatzis, P. and Karamitrou, A. and Ward Neale, J. and Harmon, N. and Rychert, C. A. and Srokosz, M.}
}
@article {117,
	title = {Temporal and spatial variations in seismic anisotropy and V P /V S ratios in a region of slow slip},
	journal = {Earth and Planetary Science Letters},
	volume = {532},
	year = {2020},
	pages = {115970},
	type = {Journal Article},
	abstract = {In September 2014, a five week long slow slip event (SSE) occurred near Gisborne at the northern Hikurangi subduction zone, New Zealand, and was recorded by offshore instruments deployed by the Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip (HOBITSS) project. Up to 25 cm of slip occurred directly below the HOBITSS array. We calculate shear wave splitting (SWS) and V P / V S ratios for event-station pairs on HOBITSS ocean bottom seismometers and onshore GeoNet seismic stations to determine the relationship in time and space between slow slip and these seismic properties. Spatial averaging of SWS fast azimuths yields trench-perpendicular fast azimuths in some areas, suggesting that compressive stress from plate convergence closes microcracks and controls anisotropy in the upper-plate. Variations from the trench perpendicular directions are observed near a subducting seamount, with directions closely resembling fracture and fault patterns created by subducting seamounts previously observed in both laboratory and field experiments. Temporal variations in fast azimuths are observed at three stations, two of which are located above the seamount, suggesting measurable variations in stress orientations. During the SSE, median V P / V S measurements across all offshore stations increase from 1.817 to 1.894 and SWS delay times decrease from 0.178 s to 0.139 s (both changes are significant within 95\% confidence intervals). Temporal variations in V P / V S and delay time are consistent with fluid pressurization below a permeability barrier and movement of fluids during the rupture of a slow-slip patch.},
	doi = {10.1016/j.epsl.2019.115970},
	url = {https://app.dimensions.ai/details/publication/pub.1123727644},
	author = {Zal, Hubert Jerzy and Jacobs, Katrina and Savage, Martha Kane and Yarce, Jefferson and Mroczek, Stefan and Graham, Kenny and Todd, Erin K. and Nakai, Jenny and Iwasaki, Yuriko and Sheehan, Anne and Mochizuki, Kimihiro and Wallace, Laura and Schwartz, Susan and Webb, Spahr and Henrys, Stuart}
}
@article {118,
	title = {Vp/Vs Ratio of Incoming Sediments Off Cascadia Subduction Zone From Analysis of Controlled-Source Multicomponent OBS Records},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {125},
	year = {2020},
	type = {Journal Article},
	abstract = {P-to-S-converted waves observed in controlled-source multicomponent ocean bottom seismometer (OBS) records were used to derive the Vp/Vs structure of Cascadia Basin sediments. We used P-to-S waves converted at the basement to derive an empirical function describing the average Vp/Vs of Cascadia sediments as a function of sediment thickness. We derived one-dimensional interval Vp/Vs functions from semblance velocity analysis of S-converted intrasediment and basement reflections, which we used to define an empirical Vp/Vs versus burial depth compaction trend. We find that seaward from the Cascadia deformation front, Vp/Vs structure offshore northern Oregon and Washington shows little variability along strike, while the structure of incoming sediments offshore central Oregon is more heterogeneous and includes intermediate-to-deep sediment layers of anomalously elevated Vp/Vs. These zones with elevated Vp/Vs are likely due to elevated pore fluid pressures, although layers of high sand content intercalated within a more clayey sedimentary sequence, and/or a higher content of coarser-grained clay minerals relative to finer-grained smectite could be contributing factors. We find that the proto-d{\'e}collement offshore central Oregon develops within the incoming sediments at a low-permeability boundary that traps fluids in a stratigraphic level where fluid overpressure exceeds 50\% of the differential pressure between the hydrostatic pressure and the lithostatic pressure. Incoming sediments with the highest estimated fluid overpressures occur offshore central Oregon where deformation of the accretionary prism is seaward vergent. Conversely, landward vergence offshore northern Oregon and Washington correlates with more moderate pore pressures and laterally homogeneous Vp/Vs functions of Cascadia Basin sediments. Average and interval Vp/Vs versus depth functions derived from S-converted waves from the Ridge-to-Trench seismic experiment in Cascadia Basin Layers with high Vp/Vs indicate elevated pore fluid pressure in incoming sediments Variations in Vp/Vs structure correlate with underthrust sediment thickness and wedge deformation style.},
	doi = {10.1029/2019jb019239},
	url = {https://app.dimensions.ai/details/publication/pub.1127957341},
	author = {Zhu, Jian and Canales, J. Pablo and Han, Shuoshuo and Carbotte, Suzanne M. and Arnulf, Adrien and Nedimovi{\'c}, Mladen R.}
}
@article {eddy_age_2019,
	title = {Age dependence and anisotropy of surface-wave phase velocities in the Pacific},
	journal = {Geophysical Journal International},
	volume = {216},
	number = {1},
	year = {2019},
	month = {01/2019},
	pages = {640{\textendash}658},
	abstract = {We present new anisotropic phase-velocity maps of the Pacific basin for Rayleigh and Love waves between 25~and 250~s. The isotropic and anisotropic phase-velocity maps are obtained by inversion of a data set of single-station surface-wave phase-anomaly measurements recorded for paths crossing the Pacific basin. We develop an age-dependent gradient-damping scheme that allows us to reduce the amount of smoothness damping required in the inversion. The observed isotropic phase velocities have a strong age dependence, and our results are consistent with models of half-space cooling: simple phase-velocity models that depend only on seafloor age explain \$40\textbackslashtext{-}97\textbackslashhbox{ per cent}\$ of the data variance for Love waves and \$20\textbackslashtext{-}97\textbackslashhbox{ per cent}\$ for Rayleigh waves. These values represent a large fraction, ranging from 0.55 to 0.99, of the variance reduction of our best-fitting phase-velocity models. We find that 2ζ azimuthal anisotropy is required to fit our Rayleigh wave phase-anomaly data set but that our data do not require Love wave anisotropy. Rayleigh wave anisotropy also exhibits a clear age dependence, with a large decrease in the magnitude of 2ζ azimuthal anisotropy for seafloor older than 70~Ma that cannot be explained simply as a change in anisotropy direction between the lithosphere and asthenosphere. Long-period Rayleigh wave anisotropy directions align well overall with absolute-plate-motion directions, with a median angular misfit of 20{\textdegree} at 125~s. However, we observe large areas within the Pacific basin with a small but consistent offset of 10{\textdegree}{\textendash}20{\textdegree} between the two directions. The disagreement between absolute plate motion and anisotropy for long-period waves suggests the presence of mantle flow beneath the base of the plate in a direction other than absolute plate motion.},
	issn = {0956-540X},
	doi = {10.1093/gji/ggy438},
	url = {https://doi.org/10.1093/gji/ggy438},
	author = {Eddy, Celia L and Ekstr{\"o}m, G{\"o}ran and Nettles, Meredith and Gaherty, James B}
}
@article {Kuna2019,
	title = {Mode of slip and crust{\textendash}mantle interaction at oceanic transform faults},
	journal = {Nature Geoscience},
	volume = {12},
	number = {2},
	year = {2019},
	month = {feb},
	pages = {138{\textendash}142},
	issn = {1752-0894},
	doi = {10.1038/s41561-018-0287-1},
	url = {http://www.nature.com/articles/s41561-018-0287-1},
	author = {Kuna, V{\'a}clav M. and N{\'a}b{\v e}lek, John L. and Braunmiller, Jochen}
}
@article {Hooft2019,
	title = {Seismic imaging of Santorini: Subsurface constraints on caldera collapse and present-day magma recharge},
	journal = {Earth and Planetary Science Letters},
	volume = {514},
	year = {2019},
	month = {may},
	pages = {48{\textendash}61},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2019.02.033},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X19301360},
	author = {Hooft, E.E.E. and Heath, B.A. and Toomey, D.R. and Paulatto, M. and Papazachos, C.B. and Nomikou, P. and Morgan, J.V. and Warner, M.R.}
}
@article {yarce_seismicity_2019,
	title = {Seismicity at the Northern Hikurangi Margin, New Zealand, and Investigation of the Potential Spatial and Temporal Relationships With a Shallow Slow Slip Event},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {124},
	number = {5},
	year = {2019},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2018JB017211},
	pages = {4751{\textendash}4766},
	abstract = {In 2014{\textendash}2015, the Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip experiment deployed seafloor absolute pressure gauges and ocean bottom seismometers directly above a large slow slip event, allowing examination of the relationship between slow slip and earthquakes in detail. Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip data were combined with nearby existing land stations to create a catalog of microseismicity consisting of 2,300 earthquakes ranging in magnitude between 0.5 and 4.7 that is complete to magnitude 1.5, yielding almost twice as many events as detected by the onshore networks alone. This greatly improves the seismicity catalog for this active subduction zone margin, especially in the offshore portion that was difficult to study using only the inland permanent seismic network. The new locations for the events within the footprint of the offshore network show that earthquakes near the trench are systematically shallower than and NW (landward) of their locations using only land-based stations. Our results indicate that Hikurangi seismicity is concentrated in two NE-SW bands, one offshore beneath the outer forearc wedge, one onshore beneath the eastern Raukumara Peninsula, and the majority of earthquakes are within the subducting Pacific plate with a smaller percent at the plate interface. We find a 20-km wide northeast trending gap in microseismicity between the two bands and beneath the inner forearc wedge and this gap in seismicity borders the downdip edge of a slow slip patch.},
	keywords = {gap, Hikurangi, ocean bottom seismometers, seismicity, slow slip},
	issn = {2169-9356},
	doi = {10.1029/2018JB017211},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018JB017211},
	author = {Yarce, J. and Sheehan, A. F. and Nakai, J. S. and Schwartz, S. Y. and Mochizuki, K. and Savage, M. K. and Wallace, L. M. and Henrys, S. A. and Webb, S. C. and Ito, Y. and Abercrombie, R. E. and Fry, B. and Shaddox, H. and Todd, E. K.}
}
@article {Heath2019,
	title = {Tectonism and Its Relation to Magmatism Around Santorini Volcano From Upper Crustal P Wave Velocity},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {124},
	number = {10},
	year = {2019},
	month = {oct},
	pages = {10610{\textendash}10629},
	issn = {2169-9313},
	doi = {10.1029/2019JB017699},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JB017699},
	author = {Heath, B. A. and Hooft, E. E. E. and Toomey, D. R. and Papazachos, C. B. and Nomikou, P. and Paulatto, M. and Morgan, J. V. and Warner, M. R.}
}
@article {li_connections_2018,
	title = {Connections between subducted sediment, pore-fluid pressure, and earthquake behavior along the Alaska megathrust},
	journal = {Geology},
	volume = {46},
	number = {4},
	year = {2018},
	month = {02/2018},
	pages = {299{\textendash}302},
	abstract = {Variations in pore-fluid pressure along subduction megathrusts are often invoked to explain differences in fault slip behavior between margins. However, many other parameters vary between subduction zones, making it difficult to isolate the causes of elevated pore fluid pressures and their effects on megathrust behavior. Here we show evidence from pre-stack depth migrations of multichannel seismic reflection data along the subduction zone off the Alaska Peninsula for significant, systematic along-strike variations in the thickness, continuity, P-wave velocity, and estimated pore-fluid pressure of the subducting sediment layer that lines the shallow plate interface within 25 km of the trench. These variations appear to correlate with changes in seismicity, locking, and earthquake rupture history. The currently locked and seismically quiet Semidi segment has a continuous, thick (600{\textendash}900 m) subducted sediment layer that is characterized by low seismic velocities and elevated pore pressure (λ* ≈ 0.4{\textendash}0.8). The subducted sediment in the neighboring Shumagin Gap, a region with low geodetic coupling and abundant small earthquakes, is thinner, irregular and has lower pore pressure (λ* \&lt; 0.2{\textendash}0.3). We suggest that the thicker and weakly faulted sediment layer entering the trench at Semidi is associated with a continuous and overpressured sediment layer lining the shallow plate interface, but forms a large coherent asperity as it dewaters and consolidates at greater depths, thus favoring large earthquakes. In contrast, thinner incoming sediment disrupted by outer rise faulting at Shumagin results in a plate interface without elevated pore-fluid pressures, but which is heterogeneous and complex at all depths, contributing to creep and frequent small earthquakes.},
	issn = {0091-7613},
	doi = {10.1130/G39557.1},
	url = {https://doi.org/10.1130/G39557.1},
	author = {Li, Jiyao and Shillington, Donna J. and Saffer, Demian M. and B{\'e}cel, Anne and Nedimovi{\'c}, Mladen R. and Kuehn, Harold and Webb, Spahr C. and Keranen, Katie M. and Abers, Geoffrey A.}
}
@article {Accardo2018,
	title = {Constraints on Rift Basin Structure and Border Fault Growth in the Northern Malawi Rift From 3-D Seismic Refraction Imaging},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {123},
	number = {11},
	year = {2018},
	month = {nov},
	pages = {10,003{\textendash}10,025},
	issn = {21699313},
	doi = {10.1029/2018JB016504},
	url = {http://doi.wiley.com/10.1029/2018JB016504},
	author = {Accardo, N. J. and Shillington, D. J. and Gaherty, J. B. and Scholz, C. A. and Nyblade, A. A. and Chindandali, P. R. N. and Kamihanda, G. and McCartney, T. and Wood, D. and Wambura Ferdinand, R.}
}
@article {todd_earthquakes_2018,
	title = {Earthquakes and Tremor Linked to Seamount Subduction During Shallow Slow Slip at the Hikurangi Margin, New Zealand},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {123},
	number = {8},
	year = {2018},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2018JB016136},
	pages = {6769{\textendash}6783},
	abstract = {Shallow slow slip events have been well documented offshore Gisborne at the northern Hikurangi subduction margin, New Zealand, and are associated with tectonic tremor downdip of the slow slip patch and increases in local microseismicity. Tremor and seismicity on the shallow subduction interface are often poorly resolved due to their distance from land-based seismic and geodetic networks. To address this shortcoming, the Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip experiment deployed 24 absolute pressure gauges and 15 ocean bottom seismometers on the seafloor above the Gisborne slow slip patch to investigate the spatial and temporal extent of slow slip and associated tremor and earthquake activity. We present a detailed spatiotemporal analysis of the seismic signatures of various interplate slip processes associated with the September/October 2014 Gisborne slow slip event. Tectonic tremor begins toward the end and continues after the geodetically constrained slow slip event and is localized in the vicinity of two subducted seamounts within and updip of the slow slip patch. The subsequent, rather than synchronous occurrence of tremor suggests that tremor may be triggered by stress changes induced by slow slip. However, Coulomb failure stress change models based on the slow slip distribution fail to predict the location of tremor, suggesting that seamount subduction plays a dominant role in the stress state of the shallow megathrust. This and the observed interplay of seismic and aseismic interplate slip processes imply that stress changes from slow slip play a secondary role in the distribution of associated microseismicity.},
	keywords = {earthquake, New Zealand, Seamount, slow slip, subduction, tremor},
	issn = {2169-9356},
	doi = {10.1029/2018JB016136},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018JB016136},
	author = {Todd, Erin K. and Schwartz, Susan Y. and Mochizuki, Kimihiro and Wallace, Laura M. and Sheehan, Anne F. and Webb, Spahr C. and Williams, Charles A. and Nakai, Jenny and Yarce, Jefferson and Fry, Bill and Henrys, Stuart and Ito, Yoshihiro}
}
@article {Canales2017a,
	title = {Dry Juan de Fuca slab revealed by quantification of water entering Cascadia subduction zone},
	journal = {Nature Geoscience},
	volume = {10},
	number = {11},
	year = {2017},
	month = {nov},
	pages = {864{\textendash}870},
	issn = {1752-0894},
	doi = {10.1038/ngeo3050},
	url = {http://www.nature.com/articles/ngeo3050},
	author = {Canales, J. P. and Carbotte, S. M. and Nedimovi{\'c}, M. R. and Carton, H.}
}
@mastersthesis {Neale2017,
	title = {An investigation into ocean wave sources of ambient seismic noise},
	year = {2017},
	school = {University of Southampton},
	type = {phdPh.D.},
	url = {http://eprints.soton.ac.uk/id/eprint/412555},
	author = {Neale, J. F. W.}
}
@article {Byrnes2017a,
	title = {Mantle dynamics beneath the discrete and diffuse plate boundaries of the Juan de Fuca plate: Results from Casascadia Initiative body wave tomography},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {18},
	number = {8},
	year = {2017},
	month = {aug},
	pages = {2906{\textendash}2929},
	issn = {1525-2027},
	doi = {10.1002/2017GC006980},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2017GC006980},
	author = {Byrnes, Joseph S. and Toomey, Douglas R. and Hooft, Emilie E. E. and N{\'a}b{\v e}lek, John and Braunmiller, Jochen}
}
@article {Accardo2017,
	title = {Surface wave imaging of the weakly extended Malawi Rift from ambient-noise and teleseismic Rayleigh waves from onshore and lake-bottom seismometers},
	journal = {Geophysical Journal International},
	volume = {209},
	number = {3},
	year = {2017},
	month = {jun},
	pages = {1892{\textendash}1905},
	issn = {0956-540X},
	doi = {10.1093/gji/ggx133},
	url = {https://academic.oup.com/gji/article/209/3/1892/3098113},
	author = {Accardo, N.J. and Gaherty, J.B. and Shillington, D.J. and Ebinger, C.J. and Nyblade, A.A. and Mbogoni, G.J. and Chindandali, P.R.N. and Ferdinand, R.W. and Mulibo, G.D. and Kamihanda, G. and Keir, D. and Scholz, C. and Selway, K. and O{\textquoteright}Donnell, J.P. and Tepp, G. and Gallacher, R. and Mtelela, K. and Salima, J. and Mruma, A.}
}
@article {becel_tsunamigenic_2017,
	title = {Tsunamigenic structures in a creeping section of the Alaska subduction zone},
	journal = {Nature Geoscience},
	volume = {10},
	number = {8},
	year = {2017},
	note = {Publisher: Nature Publishing Group},
	pages = {609{\textendash}613},
	abstract = {Segments of subduction zones that are capable of generating tsunamigenic earthquakes appear to have characteristic structural configurations. These structures include heterogeneous plate interfaces, a small wedge of deformed sediment at the toe of the overriding plate (the frontal prism), and splay faults in the crust of the overriding plate that root within the plate boundary megathrust. Here we use seismic reflection imaging to show that these features also exist within a creeping segment of the Alaska subduction zone, the Shumagin Gap. We identify an active crustal-scale normal fault system that dips landward and resembles that involved in the 2011 Tohoku-oki earthquake in Japan. We also find that the Shumagin Gap has a small frontal prism, a deep-water splay fault, and that the plate interface here is rough and thinly sedimented. We propose that lateral propagation of rupture from a neighbouring segment into the Shumagin Gap may explain a tsunamigenic earthquake that occurred there in 1788 and that tsunamigenic potential should be considered in hazard assessments for the region. Our results demonstrate that structural configurations similar to those in Tohoku may exist in other subduction zones, including within creeping segments or segments with no record of historical megathrust earthquakes, but are under-recognized. Identifying similar configurations globally may improve our ability to anticipate regions capable of generating large tsunamis.},
	keywords = {Geodynamics, Geology, Natural hazards, seismology, Tectonics},
	issn = {1752-0908},
	doi = {10.1038/ngeo2990},
	url = {https://www.nature.com/articles/ngeo2990},
	author = {B{\'e}cel, Anne and Shillington, Donna J. and Delescluse, Matthias and Nedimovi{\'c}, Mladen R. and Abers, Geoffrey A. and Saffer, Demian M. and Webb, Spahr C. and Keranen, Katie M. and Roche, Pierre-Henri and Li, Jiyao and Kuehn, Harold}
}
@article {Horning2016,
	title = {A 2-D tomographic model of the Juan de Fuca plate from accretion at axial seamount to subduction at the Cascadia margin from an active source ocean bottom seismometer survey},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {121},
	number = {8},
	year = {2016},
	month = {aug},
	pages = {5859{\textendash}5879},
	issn = {21699313},
	doi = {10.1002/2016JB013228},
	url = {http://doi.wiley.com/10.1002/2016JB013228},
	author = {Horning, G. and Canales, J. P. and Carbotte, S. M. and Han, S. and Carton, H. and Nedimovi{\'c}, M. R. and van Keken, P. E.}
}
@article {Shillington2016,
	title = {Acquisition of a Unique Onshore/Offshore Geophysical and Geochemical Dataset in the Northern Malawi (Nyasa) Rift},
	journal = {Seismological Research Letters},
	volume = {87},
	number = {6},
	year = {2016},
	month = {nov},
	pages = {1406{\textendash}1416},
	issn = {0895-0695},
	doi = {10.1785/0220160112},
	url = {https://pubs.geoscienceworld.org/srl/article/87/6/1406-1416/314187},
	author = {Shillington, Donna J. and Gaherty, James B. and Ebinger, Cynthia J. and Scholz, Christopher A. and Selway, Kate and Nyblade, Andrew A. and Bedrosian, Paul A. and Class, Cornelia and Nooner, Scott L. and Pritchard, Matthew E. and Elliott, Julie and Chindandali, Patrick R. N. and Mbogoni, Gaby and Ferdinand, Richard Wambura and Boniface, Nelson and Manya, Shukrani and Kamihanda, Godson and Saria, Elifuraha and Mulibo, Gabriel and Salima, Jalf and Mruma, Abdul and Kalindekafe, Leonard and Accardo, Natalie J. and Ntambila, Daud and Kachingwe, Marsella and Mesko, Gary T. and McCartney, Tannis and Maquay, Melania and O{\textquoteright}Donnell, J. P. and Tepp, Gabrielle and Mtelela, Khalfan and Trinhammer, Per and Wood, Douglas and Aaron, Ernest and Gibaud, Mark and Rapa, Martin and Pfeifer, Cathy and Mphepo, Felix and Gondwe, Duncan and Arroyo, Gabriella and Eddy, Celia and Kamoga, Brian and Moshi, Mary}
}
@article {webb_high-resolution_2016,
	title = {High-Resolution Seafloor Absolute Pressure Gauge Measurements Using a Better Counting Method},
	journal = {Journal of Atmospheric and Oceanic Technology},
	volume = {33},
	number = {9},
	year = {2016},
	note = {Publisher: American Meteorological Society Section: Journal of Atmospheric and Oceanic Technology},
	month = {sep},
	pages = {1859{\textendash}1874},
	abstract = {Abstract Vibrating quartz force transducers are the critical component of most deep-sea pressure and depth gauges in use in oceanography, producing a frequency output that varies with pressure. Accurate and low drift pressure measurements can be obtained by precisely measuring this frequency. In most implementations, the frequency is determined by counting the number of cycles of a high-frequency standard oscillator occurring during a large number of cycles of the lower-frequency quartz force oscillator. Resolution is limited by the sampling interval (length of counting) and the frequency of the frequency standard. Alternative counting methods can provide significant (20{\textendash}40 dB) improvements in resolution at sampling rates above 1 Hz. Each counting method can be described as a different filter applied to the output of a counter of the frequency standard gated at each transition of the transducer quartz oscillator. Improvements in resolution can be understood as the result of minimizing the aliasing of higher-frequency counting noise into the spectrum below the Nyquist frequency. A simple multipole infinite impulse response (IIR) filter designed to limit spectral leakage of high-frequency noise minimizes the noise spectrum and thereby optimizes the resolution of the pressure output. The resultant noise spectrum rises as frequency squared above 1 Hz, independent of the sampling rate. At frequencies below 1 Hz, it is limited by noise in the electronics driving the force transducer quartz oscillator. Resolution increases with frequency of the frequency standard up to about 200 MHz, plateauing for higher frequencies due to other noise sources (likely electronic).},
	issn = {0739-0572, 1520-0426},
	doi = {10.1175/JTECH-D-15-0114.1},
	url = {https://journals.ametsoc.org/view/journals/atot/33/9/jtech-d-15-0114_1.xml},
	author = {Webb, Spahr C. and Nooner, Scott L.}
}
@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 {Masy2015,
	title = {Lithospheric expression of cenozoic subduction, mesozoic rifting and the Precambrian Shield in Venezuela},
	journal = {Earth and Planetary Science Letters},
	volume = {410},
	year = {2015},
	month = {jan},
	pages = {12{\textendash}24},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2014.08.041},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X14005652},
	author = {Masy, Jeniffer and Niu, Fenglin and Levander, Alan and Schmitz, Michael}
}
@article {Becel2015,
	title = {Origin of dipping structures in fast-spreading oceanic lower crust offshore Alaska imaged by multichannel seismic data},
	journal = {Earth and Planetary Science Letters},
	volume = {424},
	year = {2015},
	month = {aug},
	pages = {26{\textendash}37},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2015.05.016},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X15003052},
	author = {B{\'e}cel, Anne and Shillington, Donna J. and Nedimovi{\'c}, Mladen R. and Webb, Spahr C. and Kuehn, Harold}
}
@article {Bodmer2015,
	title = {Seismic anisotropy beneath the Juan de Fuca plate system: Evidence for heterogeneous mantle flow},
	journal = {Geology},
	year = {2015},
	month = {nov},
	pages = {G37181.1},
	issn = {0091-7613},
	doi = {10.1130/G37181.1},
	url = {https://pubs.geoscienceworld.org/geology/article/43/12/1095-1098/131775},
	author = {Bodmer, Miles and Toomey, Douglas R. and Hooft, Emilie E. and N{\'a}b{\v e}lek, John and Braunmiller, Jochen}
}
@article {Neale2015,
	title = {Source regions and reflection of infragravity waves offshore of the USA{\textquoteright}s Pacific Northwest},
	journal = {Journal of Geophysical Research: Oceans},
	volume = {120},
	number = {9},
	year = {2015},
	month = {sep},
	pages = {6474{\textendash}6491},
	issn = {2169-9275},
	doi = {10.1002/2015JC010891},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2015JC010891},
	author = {Neale, Jennifer and Harmon, Nicholas and Srokosz, Meric}
}
@article {takeo_estimation_2014,
	title = {Estimation of azimuthal anisotropy in the NW Pacific from seismic ambient noise in seafloor records},
	journal = {Geophysical Journal International},
	volume = {199},
	number = {1},
	year = {2014},
	pages = {11{\textendash}22},
	abstract = {We analysed background surface waves in seismic ambient noise by cross-correlating continuous records of eight ocean bottom seismometers and nine differential pressure gauges deployed in the northwestern Pacific Ocean by the PLATE project. After estimating the clock delay and instrumental phase responses of differential pressure gauges by using cross-correlation functions, we measured average phase velocities in the area of the array for the fundamental-, first higher- and second higher-mode Rayleigh waves, and the fundamental-mode Love waves at a period range of 3{\textendash}40 s by waveform fitting. We then measured phase-velocity anomalies of fundamental-mode and first higher-mode Rayleigh waves for each pair of stations at a period range of 5{\textendash}25 s, and corrected the effect of variation in water-depths. The seismic anomalies imply the presence of strong azimuthal anisotropy beneath the eastern part of array. The direction of maximum velocity is approximately N35{\textdegree}E in the fossil seafloor spreading direction perpendicular to magnetic lineations from the ancient triple junction at this location. The peak-to-peak intensity of shear-wave velocity anisotropy in the mantle is~\~{}7~per cent.},
	issn = {0956-540X},
	doi = {10.1093/gji/ggu240},
	url = {https://doi.org/10.1093/gji/ggu240},
	author = {Takeo, Akiko and Forsyth, Donald W. and Weeraratne, Dayanthie S. and Nishida, Kiwamu}
}
@article {miller_upper_2009,
	title = {Upper mantle structure beneath the Caribbean-South American plate boundary from surface wave tomography},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {114},
	number = {B1},
	year = {2009},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2007JB005507},
	abstract = {We have measured shear wave velocity structure of the crust and upper mantle of the Caribbean-South American boundary region by analysis of fundamental mode Rayleigh waves in the 20- to 100-s period band recorded at the BOLIVAR/GEODINOS stations from 2003 to 2005. The model shows lateral variations that primarily correspond to tectonic provinces and boundaries. A clear linear velocity change parallels the plate bounding dextral strike-slip fault system along the northern coast of Venezuela, illustrating the differences between the South American continental lithosphere, the Venezuelan archipelago, and the Caribbean oceanic lithosphere. At depths up to 120 km beneath the Venezuelan Andes and the Maracaibo block, there is evidence of underthrusting of the Caribbean plate, but there is no other evidence of subduction of the Caribbean plate beneath the South American plate. In eastern Venezuela, linear crustal low velocities are associated with the fold and thrust belts whereas as higher crustal velocities are imaged in the Guayana shield lithosphere. The subducting oceanic part of the South American plate is imaged beneath the Antilles arc. The surface wave images combined with seismicity data suggest shear tearing of the oceanic lithosphere away from the buoyant continental South American plate offshore of northeastern Venezuela. The continental lithosphere south of the slab tear is bent down toward the plate boundary in response to the propagating tear in the lithosphere. We interpret a nearly vertical low-velocity {\textquotedblleft}column{\textquotedblright} west of the tear centered beneath the Cariaco Basin, with three-dimensional asthenospheric flow around the southern edge of the subducting oceanic lithosphere, with the asthenosphere escaping from beneath continental South America and rising into the plate boundary zone. The complex plate boundary structure is best examined in three dimensions. We discuss the new surface wave tomographic inversion in the context of results from other researchers including local seismicity, teleseismic shear wave splits, and interpretations from active source profiling.},
	keywords = {plate boundary, surface wave tomography, upper mantle structure},
	issn = {2156-2202},
	doi = {10.1029/2007JB005507},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2007JB005507},
	author = {Miller, Meghan S. and Levander, Alan and Niu, Fenglin and Li, Aibing}
}
@article {niu_receiver_2007,
	title = {Receiver function study of the crustal structure of the southeastern Caribbean plate boundary and Venezuela},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {112},
	number = {B11},
	year = {2007},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2006JB004802},
	abstract = {We have investigated crustal thickness and composition across the southeastern Caribbean plate boundary with the receiver function technique. We used teleseismic data recorded by a temporary broadband array deployed under the BOLIVAR project and the permanent national seismic network of Venezuela. We used the primary P-to-S conversion and crustal reverberations to estimate crustal thickness and average crustal VP/VS ratio over the region. We observe large variations in crustal thickness and Poisson{\textquoteright}s ratio. Estimated Moho depth ranges from \~{}16 km beneath the southeastern Caribbean Sea to \~{}52 km beneath northeastern Venezuela and the Venezuelan Andes. There is a good correlation between crustal structure and tectonic terranes. Data from the Precambrian Guayana Shield suggest that the underlying crustal structure is relatively uniform with a moderate thickness (\~{}37 km) and an intermediate composition. A thick crust is found below the foreland basins. The two mountain systems in northern Venezuela, the Serrania del Interior and the Serrania del Falcon, have a thin crust with arc composition and are likely dynamically supported by elastic rebound or underthrusting of the oceanic plateau that characterizes the southern Caribbean. On the other hand, the Venezuelan Andes and Perija Range on the western side of the country are probably isostatically balanced by thick crustal roots.},
	keywords = {Moho depth, southeast Caribbean, VP/VS ratio},
	issn = {2156-2202},
	doi = {10.1029/2006JB004802},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2006JB004802},
	author = {Niu, Fenglin and Bravo, Tammy and Pavlis, Gary and Vernon, Frank and Rendon, Herbert and Bezada, Maximiliano and Levander, Alan}
}
