@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}
}
@conference {schmidt-aursch_noise_2022,
	title = {Noise characteristics of ocean-bottom seismometer data in the Bransfield Strait, Antarctica},
	booktitle = {EPIC348. Sitzung der AG Seismologie, M{\"u}nster, 2022-09-26-2022-09-29},
	year = {2022},
	month = {sep},
	address = {M{\"u}nster},
	abstract = {All seismological data contain not only desired source signals, but also noise. There are various natural and artificial noise sources like wind, waves, traffic, industry, etc. Data recorded by ocean-bottom seismometers (OBS) show a different content of noise than onshore data; mainly because the OBS are located directly in one of the major noise generators: the oceans. Oceanic microseisms dominate the recordings over a broad frequency band, and there are several noise sources not known onshore, e.g. marine mammals, ship traffic, marine seismic surveys and especially in the polar regions sea ice and icebergs. In the framework of the BRAVOSEIS project, eight broadband ocean-bottom seismometers were deployed for one year in the Bransfield Strait, Antarctica. The ambient noise was helpful to correct the clock drift of the data loggers by means of noise cross-correlations. High-resolution probabilistic power spectral densities and spectrograms were calculated for all stations and channels to study the noise-generating processes. An analysis of tidal signals were performed for various time series including temperature recordings. Although all OBS were located within the same basin, they differ significantly in their noise characteristics. The noise spectrum was divided into several frequency bands. Some bands show seasonal variations, others are persistent during the entire year. A few noise signatures are coherent between all OBS, this is typical for origins far away. Most noise sources occur very locally and are specific for each OBS depending on parameters like water depth or the abundance of deep water currents. Generally, the noise properties are complex and show a great variation in time and space.},
	url = {https://epic.awi.de/id/eprint/57417/},
	author = {Schmidt-Aursch, Mechita C. and Almendros, Javier and Geissler, Wolfram and Wilcock, William}
}
@article {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}
}
@mastersthesis {2018PhDT.........1J,
	title = {New Insights on the Structure of the Cascadia Subduction Zone from Amphibious Seismic Data},
	year = {2018},
	month = {jan},
	school = {Columbia University},
	type = {phdPh.D.},
	keywords = {Geophysics, Plate tectonics},
	author = {Janiszewski, Helen Anne}
}
@article {morton_newly_2018,
	title = {Newly detected earthquakes in the Cascadia subduction zone linked to seamount subduction and deformed upper plate},
	journal = {Geology},
	volume = {46},
	number = {11},
	year = {2018},
	month = {09/2018},
	pages = {943{\textendash}946},
	abstract = {Data from an amphibious seismic network in Cascadia (northwest North America) provide unique near-source observations to assess the influence of subducting topography on seismicity. Using subspace detection, we detect and locate 222 events in two separate clusters, near a subducted seamount and a possibly accreted seamount. Seismicity in both clusters is largely shallower than the plate interface and exhibits occasional swarm-like behavior. This implies that the seamount is subducting aseismically via weak coupling with the overriding plate, while earthquakes in the upper plate arise from a high degree of fracturing due to seamount interaction, and the accreted seamount induced similar fracturing before off-scraping.},
	issn = {0091-7613},
	doi = {10.1130/G45354.1},
	url = {https://doi.org/10.1130/G45354.1},
	author = {Morton, Emily A. and Bilek, Susan L. and Rowe, Charlotte A.}
}
@article {Soule2016,
	title = {Near-axis crustal structure and thickness of the Endeavour Segment, Juan de Fuca Ridge},
	journal = {Geophysical Research Letters},
	volume = {43},
	number = {11},
	year = {2016},
	month = {jun},
	pages = {5688{\textendash}5695},
	issn = {00948276},
	doi = {10.1002/2016GL068182},
	url = {http://doi.wiley.com/10.1002/2016GL068182},
	author = {Soule, Dax and Wilcock, William S. D. and Toomey, Douglas R. and Hooft, Emilie E. E. and Weekly, Robert T.}
}
@article {Morgan2016,
	title = {Next-generation seismic experiments {\textendash} II: wide-angle, multi-azimuth, 3-D, full-waveform inversion of sparse field data},
	journal = {Geophysical Journal International},
	volume = {204},
	number = {2},
	year = {2016},
	month = {feb},
	pages = {1342{\textendash}1363},
	issn = {0956-540X},
	doi = {10.1093/gji/ggv513},
	url = {https://academic.oup.com/gji/article-lookup/doi/10.1093/gji/ggv513},
	author = {Morgan, Joanna and Warner, Michael and Arnoux, Gillean and Hooft, Emilie and Toomey, Douglas and VanderBeek, Brandon and Wilcock, William}
}
@article {Eakin2015,
	title = {New geophysical constraints on a failed subduction initiation: The structure and potential evolution of the Gagua Ridge and Huatung Basin},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {16},
	number = {2},
	year = {2015},
	month = {feb},
	pages = {380{\textendash}400},
	issn = {15252027},
	doi = {10.1002/2014GC005548},
	url = {http://doi.wiley.com/10.1002/2014GC005548},
	author = {Eakin, Daniel H. and McIntosh, Kirk D. and Van Avendonk, H. J. A. and Lavier, Luc}
}
@article {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 {clark_negligible_2008,
	title = {Negligible convergence and lithospheric tearing along the Caribbean{\textendash}South American plate boundary at 64{\textdegree}W},
	journal = {Tectonics},
	volume = {27},
	number = {6},
	year = {2008},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2008TC002328},
	abstract = {Prior studies of the Caribbean{\textendash}South American plate boundary have suffered from poor constraint on the structure of the crust and uppermost mantle. We use a recent wide-angle velocity model from the Broadband Ocean-Land Investigation of Venezuela and the Antilles arc Region project to constrain new seismic reflection data and previously published line drawing interpretations of the Caribbean{\textendash}South American plate boundary at 64{\textdegree}W. Though commonly characterized as obliquely convergent, we determine that convergence is negligible in our study area. Previous estimates of Miocene to present north-south shortening onshore eastern Venezuela have commonly been 115 km or higher, but we constrain shortening to \~{}35 km onshore, with an additional \~{}30 km offshore. With such minor convergence, we conclude that uplift and basin subsidence in eastern Venezuela does not derive from typical collisional orogeny. Instead, the largely vertical tectonics likely result from mantle dynamics associated with an eastward propagating, near-vertical tear in the lithosphere along the former passive margin.},
	keywords = {El Pilar fault, Serrania del Interior, STEP fault},
	issn = {1944-9194},
	doi = {10.1029/2008TC002328},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2008TC002328},
	author = {Clark, S. A. and Levander, A. and Magnani, M. B. and Zelt, C. A.}
}
