Exploring the Possibilities of Passive Seismic Interferometry to Image Temperate Glaciers

To aid the general scope of a larger project studying hydrological processes occurring within and beneath glaciers, we installed a small passive seismic network on the Bench glacier, near Valdez, AK. In conjunction with active-source seismic and GPR surveys, passive data is recorded over a period of 10 days along two separate receiver arrays. Four receivers are placed on a line parallel to the glacier's movement, while six receivers form a line perpendicular to the first, traversing the glacier. Seismic interferometry is used to extract Green functions between receiver pairs. In this work we explore the use of rock falls from the surrounding mountains, water traveling within the glacier and at the glacier bed, and fracturing of the glacier ice as possible seismic sources to image the englacial and subglacial systems. Aided by the low intrinsic seismic energy loss of ice and a favorable distribution of natural sources, it may be possible to use passive seismic imaging to help us understand key glacial processes such as fracture formation and water movement from the surface to the bed of the glacier.