Passive seismic methods form the core of this 3-year, multi-disciplinary proposal designed to investigate temporal and spatial relationships between ice motion, basal processes and iceberg calving at a rapidly changing tidewater glacier. The proposed measurements will link glacier-generated seismic signatures to physical glaciological processes. At present, glacier generated waveforms are poorly understood. Understanding their source mechanisms could advance knowledge of the dynamic mass balance of Earth?s cryosphere, as well as improve models and understanding of glacier erosion and landscape evolution. Preliminary results from a 1-year pilot study highlight the tidewater glaciers of Icy Bay, Alaska as the regionally dominant source of glacier-generated seismic energy. Icy Bay is the optimal study site because of its highly dynamic glaciers, logistical simplicity and similarities with disintegrating outlet glaciers in Greenland. Pilot study results show potential to make use of long duration, high-resolution records of motion, seismicity and changes in geometry in concert to develop quantitative proxies for glacier erosion.
The proposed work will record seismic events within a local network with dense station spacing, and simultaneously observe 3-D ice displacement and glacier geometry changes. Iceberg calving and basal processes are challenging to measure, and applying readily available and highly developed seismic methods to these problems holds significant promise. The proposal will support the collaboration of three early-career scientists with multi-disciplinary backgrounds. Data from the experiments will be archived at UNAVCO, IRIS, NSIDC and at the University of Alaska.