@article {anderson_deformation_2025,
	title = {Deformation on Rainbow Massif, Mid-Atlantic Ridge, Illuminated With Microearthquakes Detected by Machine Learning},
	journal = {Geophysical Research Letters},
	volume = {52},
	number = {2},
	year = {2025},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2024GL111285},
	pages = {e2024GL111285},
	abstract = {Abstract Oceanic detachment fault systems are characteristic of slow-spreading mid-ocean ridges, where reduced magma supply leads to increased extension by faulting and exhumation of oceanic core complexes (OCCs). OCCs have complicated structure reflecting the interplay between magmatic, hydrothermal, and tectonic processes. We use microearthquake data from a 9-month ocean bottom seismometer deployment to image deformation structures in the Rainbow massif on the Mid-Atlantic Ridge. Using a machine-learning enabled workflow to obtain an earthquake catalog containing > {\vphantom} > \textbackslash68,000 events, we find seismicity occurred in distinct clusters that correlate with previously imaged velocity anomalies and dipping subsurface reflections. Our results are consistent with a dipping alteration front within the massif overlying late-stage intrusions and suggest a transpressional fault accommodates a non-transform offset north of the massif. Our results demonstrate OCCs continue to deform in a complex way after a detachment fault has been abandoned due to combined effects of tectonic stresses, magmatism, and alteration.},
	keywords = {detachment faults, machine learning, microearthquakes, oceanic core complex, slow spreading mid-ocean ridges},
	doi = {https://doi.org/10.1029/2024GL111285},
	author = {Anderson, Evan C. and Parnell-Turner, Ross and Sohn, Robert A. and Fan, Wenyuan}
}
@article {farrell_relationship_2023,
	title = {The Relationship Between Wind, Waves, Bathymetry, and Microseisms in Yellowstone Lake, Yellowstone National Park},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {128},
	number = {7},
	year = {2023},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2022JB025943},
	month = {06/2023},
	pages = {e2022JB025943},
	abstract = {We conducted a multidisciplinary geophysical experiment to study the relationship between wind, waves, bathymetry, and microseisms in Yellowstone Lake{\textemdash}a small, isolated body of water in which wind-driven gravity waves excite low-amplitude seismic energy at periods \~{}1.0 s with a regular daily pattern. During 25 June{\textendash}4 August 2018, we deployed 40 short-period seismometers, four meteorological stations, and two wave gauges in and around Yellowstone Lake. These instruments were complemented by seven permanent seismometers on the lake perimeter, and a contemporaneous deployment of 10 lake bottom seismometers (LBS) on the floor of the north-central portion of the lake. The daily wind cycle, with southwesterly winds rising from \~{}0 m/s in the early morning to maxima of 10{\textendash}15 m/s in the late afternoon, generated lake waves with significant heights of \~{}0.3{\textendash}0.4 m and dominant periods of 1.5{\textendash}2.5 s, which in turn generated microseisms with dominant periods of \~{}0.8{\textendash}1.2 s, in excellent agreement with the double-frequency generation mechanism. Microseism energy was strongest on the lake floor stations, followed by the island stations and those along the northeastern coast of the lake, suggesting that these sites are closest to the source region where interference between incident and shoreline-reflected waves is responsible for microseism generation. Smaller amplitude single-frequency microseism energy was observed primarily along the northeastern lake shoreline. Both types of microseism energy are sensitive to shoreline morphology and lake wave dynamics, such that long-term monitoring of lake microseisms may further our understanding of how these processes change over time.},
	issn = {2169-9356},
	doi = {10.1029/2022JB025943},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022JB025943},
	author = {Farrell, Jamie and Koper, Keith D. and Sohn, Robert A.}
}
@article {smalls_lakebottom_2019,
	title = {Lake-Bottom Seismograph Observations of Microseisms in Yellowstone Lake},
	journal = {Seismological Research Letters},
	volume = {90},
	number = {3},
	year = {2019},
	month = {apr},
	pages = {1200{\textendash}1208},
	abstract = {Ambient-noise records from a seismograph deployed in Yellowstone Lake during July{\textendash}August 2016 contain high-amplitude signals in the 0.4{\textendash}1.1~Hz frequency band, which exhibit strong diurnal variations. These diurnal amplitude variations are highly coherent with wind-speed data from a meteorological station on the lake{\textquoteright}s northern shore, and as the wind builds over the course of a typical summer day, the amplitude and period of the microseism signal progressively increase, consistent with the evolution of a gravity-wave amplitude spectrum. The peak spectral levels are at frequencies of \~{}1.0  Hz, which is roughly twice the peak frequency of a fetch-limited wavefield given the 10{\textendash}19~km fetch to our lake-floor station, suggesting the signals represent double-frequency microseisms. The \~{}3.4  hr lag observed between wind speed and seismic noise levels are consistent with this interpretation.},
	issn = {0895-0695},
	doi = {10.1785/0220180242},
	url = {https://doi.org/10.1785/0220180242},
	author = {Smalls, Paris T. and Sohn, Robert A. and Collins, John A.}
}
@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 {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 {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.}
}
