Direct observations of submarine melt and subsurface geometry at a tidewater glacier
Abstract
Ice loss from the world's glaciers and ice sheets contributes to sea level rise, influences ocean circulation, and affects ecosystem productivity. On-going changes in glaciers and ice sheets are driven by submarine melting and iceberg calving from tidewater glacier margins. However, predictions of glacier change largely rest on unconstrained theory for submarine melting. Here, we use repeat multibeam sonar surveys to image the subsurface face of LeConte Glacier, a tidewater glacier in southeast Alaska, and document a time-variable, three-dimensional geometry linked to melting and calving patterns. Submarine melt rates are high across the entire ice face over both seasons surveyed and increase from spring (May) to summer (August). The observed melt rates are up to two-orders of magnitude greater than predicted by theory. We extend these findings with new data from September 2018 and show pre- and post-calving morphologies of the subsurface glacier face.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.C14A..01S
- Keywords:
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- 0720 Glaciers;
- CRYOSPHERE;
- 0726 Ice sheets;
- CRYOSPHERE;
- 0728 Ice shelves;
- CRYOSPHERE;
- 4207 Arctic and Antarctic oceanography;
- OCEANOGRAPHY: GENERAL