A5051447257- Cryospheric studies and observations
- Landslides and related hazards
- Winter Sports Injuries and Performance
- Seismic Waves and Analysis
- Seismology and Earthquake Studies
- Arctic and Antarctic ice dynamics
- earthquake and tectonic studies
- Underwater Acoustics Research
- Climate change and permafrost
- Seismic Imaging and Inversion Techniques
- Hydraulic Fracturing and Reservoir Analysis
- Geotechnical and Geomechanical Engineering
- Earthquake Detection and Analysis
- Marine animal studies overview
- Methane Hydrates and Related Phenomena
- Geology and Paleoclimatology Research
- Advanced Fiber Optic Sensors
- Icing and De-icing Technologies
- Geochemistry and Geologic Mapping
- Drilling and Well Engineering
- Oceanographic and Atmospheric Processes
- Ocean Waves and Remote Sensing
- Geophysics and Sensor Technology
- Smart Materials for Construction
- Geotechnical Engineering and Underground Structures
Earth and Space Research
2021-2025
University of Washington
2021-2025
Bridge University
2022
Washington College
2022
University of Leeds
2022
University of Cambridge
2022
Planetary Science Institute
2016-2021
Harvard University
2016-2021
Seattle University
2021
Harvard University Press
2019
Climate change is increasingly predisposing polar regions to large landslides. Tsunamigenic landslides have occurred recently in Greenland ( Kalaallit Nunaat ), but none been reported from the eastern fjords. In September 2023, we detected start of a 9-day-long, global 10.88-millihertz (92-second) monochromatic very-long-period (VLP) seismic signal, originating East Greenland. this study, demonstrate how event started with glacial thinning–induced rock-ice avalanche 25 × 10 6 cubic meters...
Researchers monitor southwest Greenland’s ice sheet mass changes by measuring seismic velocity variations in crust.
Distributed acoustic sensing (DAS) is a technique that measures strain changes along an optical fiber to distances of ∼100 km with spatial sensitivity tens meters. In November 2021, 4 days DAS data were collected on two cables the Ocean Observatories Initiative Regional Cabled Array extending offshore central Oregon. Numerous 20 Hz fin whale calls, northeast Pacific blue A and B ship noises recorded, highlighting potential for monitoring ocean. The are publicly available support studies...
Abstract Distributed acoustic sensing (DAS) on submarine fiber-optic cables is providing new observational insights into solid Earth processes and ocean dynamics. However, the availability of offshore dark fibers for long-term deployment remains limited. Simultaneous telecommunication DAS operating at different wavelengths in same fiber, termed optical multiplexing, offers one solution. In May 2024, we collected a four-day dataset utilizing an L-band interrogator multiplexing Ocean...
El Mayor-Cucapah earthquake occurred on 4 April 2010 in northeastern Baja California just south of the U.S.-Mexico border. The ruptured several previously mapped faults, as well some unidentified ones, including Pescadores, Borrego, Paso Inferior and Superior faults Sierra Cucapah, Indiviso fault Mexicali Valley Colorado River Delta. We conducted Global Positioning System (GPS) campaign surveys preexisting newly established benchmarks within 30 km rupture. Most were occupied days after...
Abstract Understanding deformation in ice shelves is necessary to evaluate the response of thinning. We study microseismicity associated with shelf using nine broadband seismographs deployed near a rift on Ross Ice Shelf. From December 2014 November 2016, we detect 5,948 icequakes generated by deformation. Locations were determined for 2,515 events least squares grid‐search and double‐difference algorithms. Ocean swell, infragravity waves, significant tsunami arrival do not affect...
Abstract. During the 200 km-scale stick slip of Whillans Ice Plain (WIP), West Antarctica, seismic tremor episodes occur at ice–bed interface. We interpret these as swarms small repeating earthquakes. The earthquakes are evenly spaced in time, and this even spacing gives rise to spectral peaks integer multiples recurrence frequency ∼ 10–20 Hz. conduct numerical simulations that include balance forces acting on fault, evolution rate- state-dependent fault friction, wave propagation from patch...
Abstract Oscillatory seismic signals arising from resonant vibrations of hydraulic fractures are observed in many geologic systems, including volcanoes, glaciers and ice sheets, hydrocarbon geothermal reservoirs. To better quantify the physical dimensions fluid‐filled cracks properties fluids within them, we study wave motion along a thin fracture waveguide. We present linearized analysis, valid at wavelengths greater than aperture, that accounts for quasi‐static elastic deformation walls,...
Abstract Distant storms, tsunamis, and earthquakes generate waves on floating ice shelves. Previous studies, however, have disagreed about whether the resulting wave‐induced stresses may cause shelf rift propagation. Most rifts show long periods of dormancy suggesting that they low background stress concentrations therefore be susceptible to stresses. Here I quantify Ross Ice Shelf Nascent Rift Amery Loose Tooth T2 using passive seismology. then relate these a fracture mechanical model...
ABSTRACT The evolution of glaciers and ice sheets depends on processes in the subglacial environment. Shear seismicity along ice–bed interface provides a window into these processes. Such requires rapid loss strength that is typically ascribed to rate-weakening friction, i.e., decreasing friction with sliding or rate. Many experiments have investigated glacial materials at temperate conditions typical fast flowing glacier beds. To our knowledge, however, studies all found rate-strengthening...
The Whillans Ice Plain (WIP), Antarctica, experiences twice daily tidally modulated stick‐slip cycles. Slip events last about 30 min, have sliding velocities as high ∼0.5 mm/s (15 km/yr), and total slip m. tend to occur during falling ocean tide: just after tide before low tide. To reproduce these characteristics, we use rate‐and‐state friction, which is commonly used simulate tectonic faulting, an ice stream law. This framework describes the evolving strength of ice‐bed interface throughout...
Abstract. Landslide hazard motivates the need for a deeper understanding of events that occur before, during, and after catastrophic slope failures. Due to destructive nature such events, in situ observation is often difficult or impossible. Here, we use data from network 58 seismic stations characterise large landslide at Askja caldera, Iceland, on 21 July 2014. High quality extensive coverage allow us analyse both long- short-period signals associated with landslide, thereby obtain...
Abstract Ocean swell interacting with Antarctic ice shelves produces sustained (approximately, 2×106 cycles per year) gravity-elastic perturbations deformation amplitudes near the front as large tens to hundreds of nanostrain. This process is most energetically excited during austral summer, when sea ice-induced attenuation at a minimum. A 2014–2017 deployment broadband seismographs on Ross Ice shelf, which included three stations sited, approximately, 2 km from front, reveals prolific...
Abstract. Understanding the processes that govern ice shelf extent is important to improving estimates of future sea-level rise. In present-day Antarctica, most commonly determined by propagation through-cutting fractures called rifts. Here, I present first three-dimensional analysis rift propagation. model rifts using assumptions linear elastic fracture mechanics (LEFM). The predicts may be stabilized (i.e., stop propagating) when buoyant flexure results in partial contact walls. This...
Ice shelves regulate the stability of marine ice sheets. We track fractures on Pine Island Glacier, a quickly accelerating glacier in West Antarctica that contributes more to sea level rise than any other glacier. Using an on-ice seismic network deployed from 2012 2014, we catalog icequakes dominantly consist flexural gravity waves. Icequakes occur near rift tip and two distinct areas shear margin, TerraSAR-X imagery shows significant fracture each source region. Rift-tip increase with...
Distributed acoustic sensing (DAS) is a technology that turns fiber-optic cable into an sensor by measuring the phase change of backscattered light caused changes in strain from field. In October 2022, 9 days DAS and co-located hydrophone data were collected Puget Sound near Seattle, WA. Passive continuously recorded for duration broadband source was fired several locations depths on first last days. This dataset provides comparisons between measurements demonstrates ability to measure...
Abstract The Antarctic ice sheet is buttressed by floating shelves that calve icebergs along large fractures called rifts. Despite the significant influence exerted rifting on shelf geometry and buttressing, scarcity of in situ observations rift propagation contributes considerable uncertainty to understanding dynamics. Here, we report first‐ever seismic recording a multiple‐kilometer event. Remote sensing recordings reveal Pine Island Glacier Ice Shelf extended 10.53 km at speed 35.1 m/s,...
Abstract Significant interest has developed in using optical fibers for seismology through Distributed Acoustic Sensing (DAS). However, converting DAS strain measurements to actual ground motions can result errors and uncertainties due imperfect coupling of the fiber earth instrument response functions. To address this, we conducted a comparative analysis data recorded by DAS, Optical Fiber Strainmeters (OFSs), estimates derived from seismic data. This study used dark commercial cable...
Mass loss from the Greenland Ice Sheet is a major contributor to sea level rise, driven primarily by increased surface melting and dynamic mass loss. Tidewater glaciers, which extend ice sheet terminate in fjords, drive through frontal ablation at their termini calving oceanic melt. Calving rates style vary substantially over time between individual making general parameterizations difficult. Capturing spatially temporally high-resolution observations of particularly challenging due harsh...
Crevassing plays an important role for the stability of glaciers and ice shelves. While dry crevasses are limited in their depth propagation by surrounding stress field, filled with water can become unstable propagate far deeper, providing a route meltwater to reach glacier bed. Hydrofracture-driven crevassing therefore has potential destabilise also been shown cause rapid shelf disintegration. However, physical mechanisms associated hydrofracture seldom observed. Icequakes generated...
Abstract Earthquake source time functions carry information about the complexity of seismic rupture. We explore databases earthquake and find that they are composed distinct peaks we call subevents. observe complexity, as represented by number subevents, grows with magnitude. Patterns in rupture arise from a scaling between subevent moment main event moment. These results can be explained simple 2‐D dynamic simulations self‐affine heterogeneity fault prestress. Applying this to early...
Abstract Frictional instabilities exist in many geological settings, including glaciers and tectonic plate boundaries. However, investigations of suggested analogies between stick‐slip “icequakes” earthquake faulting have been hampered by the noisy, melt‐prone inaccessible nature glacial environments. Here, we reveal details events beneath an Alpine glacier using seismic sensors within a few meters seismically active bed region. We present evidence that widely detected events, which are...
Abstract Ice sheet evolution depends on subglacial conditions, with the ice‐bed interface's strength exerting an outsized role ice dynamics. Along fast‐flowing glaciers, this is often controlled by deformation of till, making quantification spatial variations till essential for understanding ice‐sheet contribution to sea‐level. This task remains challenging due a lack in situ observations. We analyze continuous seismic data from Whillans Plain (WIP), West Antarctica, uncover spatio‐temporal...