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| Titel |
An up-close examination of tidewater outlet-glacier flow and glacial earthquakes using GPS |
| VerfasserIn |
P. Elosegui, M. Nettles, J. de Juan, J. L. Davis, G. S. Hamilton, T. B. Larsen |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250026991
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| Zusammenfassung |
| There is overwhelming evidence that fast-moving tidewater glaciers in Greenland have
recently experienced extraordinary changes in flow speed, thickness, and calving-front
position in response to environmental forcing. These changes are also often accompanied by
glacial earthquakes, whose number has increased in recent years. Helheim Glacier and
Kangerdlugssuaq Glacier in East Greenland exemplify such behavior, and are the focus of a
coordinated effort to understand their kinematics and dynamics. As part of this effort, we
deployed an array of geodetic, seismological, oceanographic, and other sensors on and
around Helheim Glacier during the Arctic summers of 2006–2008. The high-rate GPS data
acquired during these campaigns reveal several fascinating aspects of Helheim Glacier’s
behavior, including significant spatio-temporal variation in glacier flow, large accelerations
during glacial earthquakes, and glacier speed modulation due to ocean tidal forcing.
To extend the glacier observing period beyond the summer and help ensure data
return in this hazardous environment, we have developed a high accuracy, low-cost,
L1-only GPS receiving system that enables determination of glacier flow with both
high temporal sampling and high spatial density. The system includes two-way
communications, thus also enabling real-time monitoring and remote GPS data retrieval. We
deployed two continuously operating networks of such GPS instruments, at Helheim
Glacier and Kangerdlugssuaq Glacier, at the end of the summer of 2008 to help
characterize seasonal flow dynamics. We present our GPS analysis, and discuss our
current understanding pertaining to glacier flow and glacial earthquakes as derived
from the GPS data acquired during the summer campaigns and by these new GPS
instruments. |
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