University of California Santa Cruz
Santa Cruz, California
Supporting Stations: McMurdo Station
Research Locations: Subglacial Lake Whillans
A component of WISSARD, this project focuses on deployment of a surface passive seismic network and an array of borehole seismometers on Whillans Ice Stream (WIS) in the vicinity of Subglacial Lake Whillans (SLW). The seismic data will help to reveal the role of subglacial hydrology in controlling temporal variability of ice stream dynamics and mass balance. Specifically, borehole seismology will allow basal earthquakes and seismic signals generated by subglacial hydrology to be recorded and studied that are orders of magnitude smaller and have a more complete frequency content than possible using surface instrumentation alone. Determination of the source characteristics of basal events will permit the role of small asperities or ‘sticky spots’ in controlling basal motion to be assessed. The study area experiences large changes in ice velocity in response to tidally triggered stick-slip cycles of the WIS and periodic filling and draining of SLW, allowing the characteristics of basal motion during fast and slow ice movement and subglacial lake inflow, outflow, and quiescence to be compared.
Field Season Overview:
Two participants will deploy to McMurdo and to the WISSARD work site in West Antarctica. Using the portable ice drill, they will punch two 600-meter boreholes in the vicinity of the main WISSARD borehole (up to a few kilometers away) and deploy borehole seismometer strings in each hole. In addition to the borehole instrumentation, team members will deploy a small network (ten stations) of surface seismometers around the boreholes. If the portable drill is not available they will deploy one borehole string in the main WISSARD hole after all other activities have been completed.
Deploying Team Members: