Sudden increase in tidal response linked to calving and acceleration at a large Greenland outlet glacier

Julia de Juan, Pedro Elósegui, Meredith Nettles, Tine B. Larsen, James L. Davis, Gordon S. Hamilton, Leigh A. Stearns, Morten L. Andersen, Göran Ekström, Andreas P. Ahlstrøm, Lars Stenseng, Shfaqat Abbas Khan, René Forsberg

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Large calving events at Greenland's largest outlet glaciers are associated with glacial earthquakes and near-instantaneous increases in glacier flow speed. At some glaciers and ice streams, flow is also modulated in a regular way by ocean tidal forcing at the terminus. At Helheim Glacier, analysis of geodetic data shows decimeter-level periodic position variations in response to tidal forcing. However, we also observe transient increases of more than 100% in the glacier's responsiveness to such tidal forcing following glacial-earthquake calving events. The timing and amplitude of the changes correlate strongly with the step-like increases in glacier speed and longitudinal strain rate associated with glacial earthquakes. The enhanced response to the ocean tides may be explained by a temporary disruption of the subglacial drainage system and a concomitant reduction of the friction at the ice-bedrock interface, and suggests a new means by which geodetic data may be used to infer glacier properties.
Original languageEnglish
JournalGeophysical Research Letters
Volume37
ISSN0094-8276
DOIs
Publication statusPublished - 2010

Fingerprint

Dive into the research topics of 'Sudden increase in tidal response linked to calving and acceleration at a large Greenland outlet glacier'. Together they form a unique fingerprint.

Cite this