Ice flow models and glacial erosion over multiple glacial–interglacial cycles
Mountain topography is constructed through a variety of interacting processes. Over glaciological timescales, even simple representations of glacial-flow physics can reproduce many of the distinctive features formed through glacial erosion. However, detailed comparisons at orogen time and length sca...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-03-01
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| Series: | Earth Surface Dynamics |
| Online Access: | http://www.earth-surf-dynam.net/3/153/2015/esurf-3-153-2015.pdf |
| Summary: | Mountain topography is constructed through a variety of interacting
processes. Over glaciological timescales, even simple representations of
glacial-flow physics can reproduce many of the distinctive features formed
through glacial erosion. However, detailed comparisons at orogen time and
length scales hold potential for quantifying the influence of glacial physics
in landscape evolution models. We present a comparison using two different
numerical models for glacial flow over single and multiple glaciations,
within a modified version of the ICE-Cascade landscape evolution model. This
model calculates not only glaciological processes but also hillslope and
fluvial erosion and sediment transport, isostasy, and temporally and
spatially variable orographic precipitation. We compare the predicted
erosion patterns using a modified SIA as well as a nested, 3-D Stokes flow
model calculated using COMSOL Multiphysics.
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Both glacial-flow models predict different patterns in time-averaged erosion
rates. However, these results are sensitive to the climate and the ice
temperature. For warmer climates with more sliding, the higher-order model
yields erosion rates that vary spatially and by almost an order of magnitude
from those of the SIA model. As the erosion influences the basal topography
and the ice deformation affects the ice thickness and extent, the
higher-order glacial model can lead to variations in total ice-covered area
that are greater than 30% those of the SIA model, again with larger
differences for temperate ice. Over multiple glaciations and long timescales, these results suggest that higher-order glacial
physics should be considered, particularly in temperate, mountainous settings. |
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| ISSN: | 2196-6311 2196-632X |