HR: 13:55h
AN: G33C-02 INVITED    [Abstracts]
TI: Geodetic Measurements and Analysis of Glacier Kinematics in East Greenland
AU: * Elosegui, P
EM: pelosegui@ice.csic.es
AF: Institute for Space Sciences, CSIC/IEEC, Barcelona, 08034, Spain
AU: Davis, J L
EM: jdavis@cfa.harvard.edu
AF: Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, United States
AU: Nettles, M
EM: nettles@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, United States
AU: Larsen, T B
EM: tbl@geus.dk
AF: Geological Survey of Denmark and Greenland, GEUS, Copenhagen, Dk-2100, Denmark
AU: Ahlstrøm, A P
EM: apa@geus.dk
AF: Geological Survey of Denmark and Greenland, GEUS, Copenhagen, Dk-2100, Denmark
AU: de Juan, J
EM: dejuan@ice.csic.es
AF: Institute for Space Sciences, CSIC/IEEC, Barcelona, 08034, Spain
AU: Ekström, G
EM: ekstrom@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, United States
AU: Forsberg, R
EM: rf@spacecenter.dk
AF: Danish National Space Center, DRC, Copenhagen, DK-2100, Denmark
AU: Hamilton, G
EM: gordon.hamilton@maine.edu
AF: Climage Change Institute, University of Maine, Orono, ME 04469, United States
AU: Khan, S A
EM: abbas@spacecenter.dk
AF: Danish National Space Center, DRC, Copenhagen, DK-2100, Denmark
AU: Andersen, M
EM: mola@geus.dk
AF: Geological Survey of Denmark and Greenland, GEUS, Copenhagen, Dk-2100, Denmark
AU: Stearns, L A
EM: leigh.stearns@maine.edu
AF: Climage Change Institute, University of Maine, Orono, ME 04469, United States
AU: Stenseng, L
EM: stenseng@spacecenter.dk
AF: Danish National Space Center, DRC, Copenhagen, DK-2100, Denmark
AB: The harsh environment on the highly crevassed surfaces of fast-flowing tidewater glaciers makes the acquisition of in situ geodetic measurements, such as GPS, extremely difficult. These measurements, however, provide key information pertaining to glacier dynamics, including glacial earthquakes, and help improve our understanding of the complex interactions between the cryosphere, the atmosphere, the lithosphere, and the oceans. The kinematic analysis of high-rate GPS data acquired in these environments is also challenging. Although this analysis shares many features with the analysis of high-rate GPS data in the application known as "GPS seismology," it also has its own peculiarities. These derive largely, though not exclusively, from the fast background velocities that are characteristic of ice flow but absent in tectonically induced seismic motions. In a concerted multidisciplinary effort, we acquired, along with other geophysical observations, continuous, high- rate GPS measurements at several locations on Helheim Glacier, East Greenland, for about two months during the Arctic summers of 2006 and 2007. Analysis of these GPS observations indicates that Helheim Glacier velocities ranged between ~25~m~d^-1 at the calving front to ~5~m~d^-1 at an upglacier distance of ~35~km, with significant departures from simple, linear motion at both inter- and intra-day timescales. This presentation will focus on the geodetic approach to data acquisition and data analysis from these glaciers, with emphasis on the accuracy and temporal resolution that can be achieved. Furthermore, we will discuss ongoing hardware-directed efforts to develop accurate, robust, and inexpensive GPS systems that may serve to ameliorate some of the observational difficulties associated with "GPS glaciology" without compromising its resultant accuracy.
DE: 0720 Glaciers
DE: 0794 Instruments and techniques
DE: 1211 Non-tectonic deformation
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 1241 Satellite geodesy: technical issues (6994, 7969)
SC: Geodesy [G]
MN: 2007 Fall Meeting