Calving relation for tidewater glaciers based on detailed stress field analysis
Ocean-terminating glaciers in Arctic regions have undergone rapid dynamic changes in recent years, which have been related to a dramatic increase in calving rates. Iceberg calving is a dynamical process strongly influenced by the geometry at the terminus of tidewater glaciers. We investigate the...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-02-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/12/721/2018/tc-12-721-2018.pdf |
| Summary: | Ocean-terminating glaciers in Arctic regions have undergone rapid
dynamic changes in recent years, which have been related to a dramatic
increase in calving rates. Iceberg calving is a dynamical process
strongly influenced by the geometry at the terminus of tidewater
glaciers. We investigate the effect of varying water level, calving
front slope and basal sliding on the state of stress and flow regime
for an idealized grounded ocean-terminating glacier and scale these
results with ice thickness and velocity. Results show that water depth
and calving front slope strongly affect the stress state while the
effect from spatially uniform variations in basal sliding is much
smaller. An increased relative water level or a reclining calving
front slope strongly decrease the stresses and velocities in the
vicinity of the terminus and hence have a stabilizing effect on the
calving front. We find that surface stress magnitude and distribution
for simple geometries are determined solely by the water depth
relative to ice thickness. Based on this scaled relationship for the
stress peak at the surface, and assuming a critical stress for damage
initiation, we propose a simple and new parametrization for calving
rates for grounded tidewater glaciers that is calibrated with
observations. |
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| ISSN: | 1994-0416 1994-0424 |