Shearing in a Warmer Climate: Insights from Observations and Modeling on Hydrologic Perturbations of an Outlet Glacier
Abstract
The impact of surface melt water on ice dynamics via supraglacial lake drainage and runoff has been well documented. Little attention has been focused on direct injection of surface melt water into the shear margins of fast flowing, marine-terminating outlet glaciers. Our initial work was the first to characterize water-filled crevasse ponds within the shear margins of Jakobshavn Isbræ and assessment the volume of infiltrated melt water potentially reaching the bed. In the intervening years since this seminal work, we have utilized satellite observations and numerical models to decode the impact of hydrologic shear weakening due to melt water injection from these structures. We have constrained the theoretical impact of hydrologic shear weakening on extra-marginal ice flow using diagnostic models and provide projections for flow enhancement under future warming scenarios. For select seasons, we assessed relationships between extra-marginal, summer-time ice velocities and drainage of water-filled crevasses. We are starting to understand factors that drive how these crevasse systems fill and drain. Lastly, we have characterized the spatial and temporal variability of these structures over a 16 year period. Insights gained from these various efforts are starting to produce a comprehensive assessment of how supraglacial hydrology can influence the dynamics of marine-terminating outlet glacier systems.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.C51G1152B
- Keywords:
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- 0720 Glaciers;
- CRYOSPHEREDE: 0726 Ice sheets;
- CRYOSPHEREDE: 1827 Glaciology;
- HYDROLOGYDE: 1863 Snow and ice;
- HYDROLOGY