The internal deformation regime of Thwaites Glacier
Internal deformation is the main process controlling ice flow in ice shelves and inslow-moving regions of polar ice sheets where the ice is frozen to the bed. However, thecontribution of internal deformation to flow in ice streams and fast-flowing regions is typicallypoorly constrained in ice sheet...
| Main Authors: | , , , |
|---|---|
| Format: | Conference Object |
| Language: | English |
| Published: |
.
2019
|
| Subjects: | |
| Online Access: | https://www.waisworkshop.org/workshop-2019#Agenda http://ecite.utas.edu.au/135523 |
| Summary: | Internal deformation is the main process controlling ice flow in ice shelves and inslow-moving regions of polar ice sheets where the ice is frozen to the bed. However, thecontribution of internal deformation to flow in ice streams and fast-flowing regions is typicallypoorly constrained in ice sheet models. The current standard description of internaldeformation used in most large-scale ice sheet models -- the Glen flow relation -- is limitedby its failure to capture the tertiary flow of anisotropic ice that prevails in polar ice sheets.Here, we compare the flow regime of Thwaites Glacier as simulated by the Glen flow relationwith a recent flow relation for anisotropic ice -- the ESTAR flow relation. With ESTAR,internal deformation contributes a factor of three times more to overall flow in the ThwaitesGlacier ice streaming zone than when using the Glen flow relation. Using temperaturedependent flow rate parameters with a stronger physical basis along with the ESTAR flowrelation together provide the best match to observed surface velocities, but parameterselection and matching (i.e. via inversion) can significantly alter the predicted flow regime.Our results have implications for ice sheet evolution and stability, and may provide insightinto an improved picture of basal sliding parameterizations. |
|---|