Ice-generated seismic events observed at the Bering Glacier

The Bering Glacier progresses downhill through the mechanisms of plastic crystal deformation and basal sliding. Two summer field campaigns involving seismic monitoring in 2007 and 2008 were conducted in order to investigate basal processes near the terminus of the glacier. Many events were observed at stations deployed on the ice in 2007 near the Grindle Hills, but owing to the large distance between stations and the short recording period, few events were large enough to be recorded on sufficient stations to be accurately located. During August 2008, five stations were deployed in the same general area on the ice with closer spacing. Using this improved array, along with stations to the south of the glacier, four events were located. Of these, three appear to have occurred at or near the base of the glacier, at a point near the terminus, where the ice is severely folded, above the possible location of the Hope Creek fault. The fourth event was farther upstream beneath or within the glacier, but its location is poorly constrained.