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| Titel |
A particle based simulation model for glacier dynamics |
| VerfasserIn |
J. A. Åström, T. I. Riikilä, T. Tallinen, T. Zwinger, D. Benn, J. C. Moore, J. Timonen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 7, no. 5 ; Nr. 7, no. 5 (2013-10-08), S.1591-1602 |
| Datensatznummer |
250085170
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| Publikation (Nr.) |
 copernicus.org/tc-7-1591-2013.pdf |
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| Zusammenfassung |
| A particle-based computer simulation model was developed for investigating
the dynamics of glaciers. In the model, large ice bodies are made of discrete
elastic particles which are bound together by massless elastic beams. These
beams can break, which induces brittle behaviour. At loads below fracture,
beams may also break and reform with small probabilities to incorporate
slowly deforming viscous behaviour in the model. This model has the advantage
that it can simulate important physical processes such as ice calving and
fracturing in a more realistic way than traditional continuum models. For
benchmarking purposes the deformation of an ice block on a slip-free surface
was compared to that of a similar block simulated with a Finite Element
full-Stokes continuum model. Two simulations were performed: (1) calving of
an ice block partially supported in water, similar to a grounded marine
glacier terminus, and (2) fracturing of an ice block on an inclined plane of
varying basal friction, which could represent transition to fast flow or
surging. Despite several approximations, including restriction to
two-dimensions and simplified water-ice interaction, the model was able to
reproduce the size distributions of the debris observed in calving, which may
be approximated by universal scaling laws. On a moderate slope, a large ice
block was stable and quiescent as long as there was enough of friction
against the substrate. For a critical length of frictional contact, global
sliding began, and the model block disintegrated in a manner suggestive of a
surging glacier. In this case the fragment size distribution produced was
typical of a grinding process. |
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