Glacier, fjord, and seismic response to recent large calving events, Jakobshavn Isbrae, Greenland

The recent loss of Jakobshavn Isbrae's extensive floating ice tongue has been accompanied by a change in near terminus behavior. Calving currently occurs primarily in summer from a grounded terminus, involves the detachment and overturning of several icebergs within 30-60 min, and produces long-lasting and far-reaching ocean waves and seismic signals, including "glacial earthquakes''. Calving also increases near-terminus glacier velocities by similar to 3% but does not cause episodic rapid glacier slip, thereby contradicting the originally proposed glacial earthquake mechanism. We propose that the earthquakes are instead caused by icebergs scraping the fjord bottom during calving. Citation: Amundson, J. M., M. Truffer, M. P. Luthi, M. Fahnestock, M. West, and R. J. Motyka (2008), Glacier, fjord, and seismic response to recent large calving events, Jakobshavn Isbr, Greenland, Geophys. Res. Lett., 35, L22501, doi: 10.1029/2008GL035281.