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Aman KC Thesis Proposal
November 18 @ 3:00 pm - 5:00 pm MST
Title: Quantifying and Analyzing the Rates of Terminus Ablation for Tidewater Glaciers in Kalallit Nunnaat (Greenland)
Abstract: Tidewater glaciers in Greenland have undergone widespread retreat and mass loss since the 1990s due to increased melting and calving. Increasing discharge and subsequent melt of icebergs have raised problems like coastal flooding, change in oceanic properties, transportation of nutrients for fish, and affected the way of living for indigenous population. Thus, it is important to quantify iceberg discharge to have better estimates for the changes happening in Greenland, and the planet. Previous studies have estimated discharge as the amount of ice flowing through a stationary gate, but the precise timing of the mass loss deviates from flux estimates due to irregular iceberg calving. Terminus ablation, accounting for both the flux of ice towards the terminus and ablation from the terminus, will provide insights on understanding glacier dynamics and the interaction occurring between the ocean and glacier margins. I will make use of a composite dataset of terminus positions with high spatiotemporal resolution to determine terminus ablation. The composite dataset has better temporal coverage but is composed of terminus delineations from many authors, resulting in anomalous spikes and/or dips in the rate of terminus change. After removing the anomalous retreat rates with a velocity filter, I hypothesize that there will be consistent seasonal and interannual patterns in terminus change for each glacier. Furthermore, I will also divide the ice sheet into regions and examine how each region has responded over the years, in the frame of longer time scale (interdecadal) and shorter time scale (interannual). Comparison to potential driving mechanisms yields insights into controls on terminus position and will be especially valuable for ice sheet mass flux estimates and/or process-based studies of iceberg calving.
Advisor: Ellyn Enderlin
Committee Members: Twila Moon, Anna Bergstrom