Investigating the Role of Buoyancy in Tidewater Glacier Iceberg Calving Dynamics
Abstract
In recent decades, many of Greenland's major outlet glaciers have retreated dramatically due to increased iceberg calving, associated with an increase in velocity and inland thinning. The potential contribution to sea level rise (SLR) of a complete collapse of the Greenland Ice Sheet (GrIS) is 7m. Iceberg calving is an important process not only as a major source of mass loss from the GrIS, but also for the controlling influence it has on the dynamics of the grounding line and over the ice sheet as a whole. Despite plenty of scientific attention and a diverse body of literature, the processes involved in calving, their controlling factors and how it feeds back into glacier and ice sheet dynamics are still not fully understood. This presents a major uncertainty into projections of SLR over the coming decades and centuries. Buoyancy forces have been proposed as a major influencing factor in inducing calving in large Greenland tidewater glaciers such as Helheim Glacier. We present a new conceptual model for buoyancy-induced calving, in which a small initial calving event quickly increases the buoyant load on the terminus, leading to fast basal crevassing and much larger calving events. Using Elmer/Ice we are able to resolve the stress distributions in high resolution at the calving front. By investigating the stress distributions induced in a buoyant calving front, we hope to gain an understanding of how environmental influences such as surface thinning and waterline notch-cutting influence the calving rate. We will provide evidence for our new conceptual model from numerical simulation results and calving observations.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.C21B0685T
- Keywords:
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- 0720 Glaciers;
- CRYOSPHEREDE: 0726 Ice sheets;
- CRYOSPHEREDE: 0774 Dynamics;
- CRYOSPHEREDE: 0798 Modeling;
- CRYOSPHERE