Step-wise changes in glacier flow speed coincide with calving and glacial earthquakes at Helheim Glacier, Greenland

• Published in: Geophysical Research Letters
• Main Authors: Nettles, Meredith, Larsen, Tine B., Elosegui, Pedro, Hamilton, Gordon S., Stearns, Leigh A., Ahlstrøm, Andreas P., Davis, James L., Andersen, Morten L., de Juan, Julia, Khan, S. Aabbas, Stenseng, Lars, Ekstrom, Göran, Forsberg, René
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2015
• Subjects: glacier dynamics; glacial earthquake; claving; Greenland; glacier
• Online Access: http://hdl.handle.net/1808/17232; https://doi.org/10.1029/2008GL036127

This is the publisher's version, also available electronically from "http://onlinelibrary.wiley.com/". [1] Geodetic observations show several large, sudden increases in flow speed at Helheim Glacier, one of Greenland's largest outlet glaciers, during summer, 2007. These step-like accelerations, detected along the length of the glacier, coincide with teleseismically detected glacial earthquakes and major iceberg calving events. No coseismic offset in the position of the glacier surface is observed; instead, modest tsunamis associated with the glacial earthquakes implicate glacier calving in the seismogenic process. Our results link changes in glacier velocity directly to calving-front behavior at Greenland's largest outlet glaciers, on timescales as short as minutes to hours, and clarify the mechanism by which glacial earthquakes occur.