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| Titel |
Investigating the flow and stress regime at the front of a tidewater outlet glacier |
| VerfasserIn |
Rémy Mercenier, Martin Luethi, Andreas Vieli, Christoph Rohner, David Small |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250126708
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| Publikation (Nr.) |
 EGU/EGU2016-6469.pdf |
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| Zusammenfassung |
| Dynamic changes in ocean-terminating glaciers are responsible for approximately half of the
current high rate of mass loss of the Greenland ice sheet. The related calving process, which
occurs when the stresses at the calving front exceed the fracture toughness of ice, is still not
well understood and poorly represented in current generation ice-sheet models, but is a
crucial requisite to understand and model dynamics and future mass loss of the ice
sheet.
Here, we use a two-dimensional finite-element model to compute the stress and flow
fields near the front of a tidewater outlet glacier. First, we perform a sensitivity analysis for an
idealized glacier exploring the effects of variable calving front slope, water depth and basal
sliding. We then apply the model to two flowlines of Eqip Sermia, an ocean terminating
outlet glacier in West Greenland. Detailed velocity and geometry measurements
obtained from terrestrial radar interferometry serve as constraints to the model.
These flowline geometries and velocities strongly differ. One flowline ends with a
∼ 50 meter vertical cliff, close to floatation, while the other has a 150-200 meter
high grounded front with a ∼ 45∘ slope and for which extrusion flow is observed.
These different geometry settings lead to substantial difference in stress and flow
regimes.
This stress analysis improves our understanding of how and where the ice is susceptible
to failure and crevasse formation for different idealized as well as real conditions. In further
work, we aim to use this information as a constraint to investigate the short-term and
long-term processes related to outlet glacier calving. |
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