HR: 09:15h
AN: C41A-06    [Abstracts]
TI: The Rapid Retreat of Jakobshavns Isbrae, West Greenland: New Field Observations of 2005 and Structural Analysis of its Evolution
AU: * Mayer, H
EM: mayerh@mechanik.tu-darmstadt.de
AF: Institut fuer Mechanik, Technische Universitaet Darmstadt, Hochschulstr. 1, Darmstadt, 64289 Germany
AU: Herzfeld, U C
EM: herzfeld@iceberg.colorado.edu
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309-0449 United States
AB: Jakobshavns Isbrae in West Greenland, a major outlet glacier of the Greenland Ice Sheet and a continuously fast-moving ice stream, has long been the fastest moving and one of the most productive glaciers on Earth. It had been moving continuously at speeds of over 20 m/day with a stable front position throughout most of the latter half of the 20th century. Changes in front position that did occur during this time period were relatively small. In 2002, this ice stream, also a tidewater glacier with a 12 km long floating tongue, apparently suddenly entered a phase of rapid retreat. The ice front started to break up, the floating tongue disintegrated, the production of icebergs increased. In July 2005, we conducted an extensive aerial survey of Jakobshavns Isbrae to measure and document the present state of retreat compared to our previous field observations since 1996. We use an approach that combines structural analysis of deformation features with continuum mechanics to assess the kinematics and dynamics of glaciers, based on aerial imagery, satellite data and GPS measurements. Results from interpretation of ERS-SAR and ASTER data from 1995 to 2005 in combination with aerial imagery from 1996 to 2005 shed light on the question of changes versus stability and their causes in the Jakobshavns Isbrae dynamical system.
DE: 0720 Glaciers
DE: 0730 Ice streams
DE: 0758 Remote sensing
DE: 0774 Dynamics
DE: 0776 Glaciology (1621, 1827, 1863)
SC: Cryosphere [C]
MN: Fall Meeting 2005