FastFind »   Lastname: doi:10.1029/ Year: | Advanced Search  

AGU: Geophysical Research Letters

 

Keywords

  • glacier dynamics
  • glacial earthquake
  • claving

Index Terms

  • Cryosphere: Glaciers
  • Cryosphere: Dynamics
  • Geodesy and Gravity: Satellite geodesy: results
  • Geodesy and Gravity: Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions
  • Seismology: Earthquake source observations

Abstract

GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L24503, 5 PP., 2008
doi:10.1029/2008GL036127

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

M. Nettles

Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA

T. B. Larsen

Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark

P. Elósegui

Institute for Space Sciences, CSIC, IEEC, Barcelona, Spain

G. S. Hamilton

Climate Change Institute, University of Maine, Orono, Maine, USA

L. A. Stearns

Climate Change Institute, University of Maine, Orono, Maine, USA

A. P. Ahlstrøm

Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark

J. L. Davis

Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA

M. L. Andersen

Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark

J. de Juan

Institute for Space Sciences, CSIC, IEEC, Barcelona, Spain

S. A. Khan

Danish National Space Center, Copenhagen, Denmark

L. Stenseng

Danish National Space Center, Copenhagen, Denmark

G. Ekström

Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA

R. Forsberg

Danish National Space Center, Copenhagen, Denmark

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.

Received 24 September 2008; accepted 13 November 2008; published 30 December 2008.

Citation: Nettles, M., et al. (2008), Step-wise changes in glacier flow speed coincide with calving and glacial earthquakes at Helheim Glacier, Greenland, Geophys. Res. Lett., 35, L24503, doi:10.1029/2008GL036127.

Cited By

Please wait one moment ...