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| Titel |
Thermodynamic and fracture mechanical processes in the context of frost wedging in ice shelves |
| VerfasserIn |
Carolin Plate, Ralf Müller, Angelika Humbert, Dietmar Gross |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250113494
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| Publikation (Nr.) |
 EGU/EGU2015-13703.pdf |
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| Zusammenfassung |
| Ice shelves, the link between ice shields or glaciers and the ocean are sensitive elements of
the polar environment. The ongoing break up and disintegration of huge ice shelf parts or
entire ice shelf demands for an explication of the underlying processes. The first analyses
of crack growth and break up events in ice shelves date back to more than half a
century. Nevertheless, the mechanisms that trigger and influence the collapse of whole
ice shelf parts are not yet fully understood. Popular presumptions link ice shelf
disintegration to surface meltwater and hydro fracturing, explaining break up events in
warm polar seasons. Fracture events during colder seasons are possibly triggered by
more complex mechanisms. A well-documented break up event at the Wilkins Ice
Shelf bridge inspires the possibility of frost wedging as disintegration cause. The
present study shows a two-dimensional thermo-dynamical model simulating the
growth of an ice lid in a water-filled crevasse for measured surface temperatures.
The influence of the crevasse geometry and the ice shelf temperature are shown.
The resulting lid thickness is then used for the linear elastic fracture mechanical
analysis. The maximum crack depth is estimated by comparing the computed stress
intensity factors to critical values KIc obtained from literature. The thermodynamic as
well as the fracture mechanical simulation are performed using the commercial
finite element code COMSOL. The computation of KI follows in post processing
routines in MATLAB exploiting the benefits of the concept of configurational forces. |
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