Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Publication Type
Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
Seismic Tremor Reveals Spatial Organization And Temporal Changes Of Subglacial Water System, Margot E. Vore, Timothy C. Bartholomaus, J. Paul Winberry, Jacob I. Walter, Jason M. Amundson
Seismic Tremor Reveals Spatial Organization And Temporal Changes Of Subglacial Water System, Margot E. Vore, Timothy C. Bartholomaus, J. Paul Winberry, Jacob I. Walter, Jason M. Amundson
All Faculty Scholarship for the College of the Sciences
Subglacial water flow impacts glacier dynamics and shapes the subglacial environment. However, due to the challenges of observing glacier beds, the spatial organization of subglacial water systems and the time scales of conduit evolution and migration are largely unknown. To address these questions, we analyze 1.5‐ to 10‐Hz seismic tremor that we associate with subglacial water flow, hat is, glaciohydraulic tremor, at Taku Glacier, Alaska, throughout the 2016 melt season. We use frequency‐dependent polarization analysis to estimate glaciohydraulic tremor propagation direction (related to the subglacial conduit location) and a degree day melt model to monitor variations in melt‐water input. We …
The 2015 Landslide And Tsunami In Taan Fiord, Alaska, Bretwood Higman, Breanyn Macinnes, Colin Bloom
The 2015 Landslide And Tsunami In Taan Fiord, Alaska, Bretwood Higman, Breanyn Macinnes, Colin Bloom
All Faculty Scholarship for the College of the Sciences
Glacial retreat in recent decades has exposed unstable slopes and allowed deep water to extend beneath some of those slopes. Slope failure at the terminus of Tyndall Glacier on 17 October 2015 sent 180 million tons of rock into Taan Fiord, Alaska. The resulting tsunami reached elevations as high as 193 m, one of the highest tsunami runups ever documented worldwide. Precursory deformation began decades before failure, and the event left a distinct sedimentary record, showing that geologic evidence can help understand past occurrences of similar events, and might provide forewarning. The event was detected within hours through automated seismological …
150 Years Of Light Absorbing Impurity Deposition On South Cascade Glacier, Washington State Usa, Dan Pittenger
150 Years Of Light Absorbing Impurity Deposition On South Cascade Glacier, Washington State Usa, Dan Pittenger
All Master's Theses
Glaciers and seasonal snowpack in Washington State have undergone significant decline over the past 50 years. While warming global temperatures are widely recognized as the cause of glacial decline, the deposition of black carbon (BC) can also contribute to increased melt. BC, commonly referred to as soot, is produced by the incomplete combustion of fossil and biofuels. These particles are subject to atmospheric transport and are deposited on snow by wind and precipitation events. When BC is deposited, it lowers the albedo of the glacial surface resulting in increased energy absorption and melt. We used a 158 m long ice …
Seismic Observations Of Transient Subglacial Water-Flow Beneath Macayeal Ice Stream, West Antarctica, J. Paul Winberry, Sridhar Anandakrishnan, Richard B. Alley
Seismic Observations Of Transient Subglacial Water-Flow Beneath Macayeal Ice Stream, West Antarctica, J. Paul Winberry, Sridhar Anandakrishnan, Richard B. Alley
All Faculty Scholarship for the College of the Sciences
New seismic observations of harmonic tremors beneath MacAyeal Ice Stream, West Antarctica are reported. Each of the two tremor events that we recorded during a six week period had sustained arrival of 3 Hz energy for approximately 10 minutes. During that time the source location migrated a few kilometers. The harmonic nature of the tremors is interpreted as the result of resonance in subglacial water-filled cracks and conduits. The duration, monochromatic nature, and movement of the tremor indicate that the source mechanism is likely flow in the subglacial water system resulting from the discharge from a small subglacial lake. Our …