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| Titel |
Diurnal ice deformation variability driven by subglacial water pressure: Observations from boreholes at the margins of the Greenland Ice Sheet |
| VerfasserIn |
M. P. Lüthi, C. Ryser, G. Catania, M. Hoffman, R. Hawley, M. Funk, T. Neumann, A. Bauder, L. Andrews, B. Moriss |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250064894
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| Zusammenfassung |
| We present measurements of ice deformation and water pressure in an array of
boreholes to the bedrock in the marginal parts of the Greenland Ice Sheet.
These boreholes were drilled in summer 2011 in two arrays separated by 7 km,
and are located downstream of Swiss Camp. At each drill site, sensor systems
recording pressure, temperature, tilt and magnetic field were installed
throughout the ice thickness of 620 and 700 m, respectively. Observed diurnal
variations of borehole tilt coincide with variations of subglacial water
pressure, and with flow acceleration at the surface. The data set is
interpreted with help of a transient ice flow model, from which synthetic tilt
curves are generated. The results indicate that the observed tilt variations
can be qualitatively reproduced if a varying viscosity of a spatially
constricted subglacial layer is prescribed. Hence it is likely that our
measurements show the reaction of the ice body to a spatially diverse pattern
of varying basal motion, controlled by subglacial water pressure. |
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