Graduate Defense: Aman KC

Thesis Information

Title: Seasonality In Terminus Ablation Rates For The Glaciers In Kalaallit Nunaat (Greenland)

Program: Master of Science in Geoscience

Advisor: Dr. Ellyn Enderlin, Geosciences

Committee Members: Dr. Twila Moon, Geosciences; and Dr. Anna Bergstrom, Geosciences

Abstract

In recent decades, the Greenland Ice Sheet (GrIS) has undergone accelerated mass loss, with a significant portion attributed to the dynamic effects of terminus retreat. However, conventional assessments of this mass loss often overlook the critical aspect of terminus change, focusing primarily on inland ice flow. This study investigates the terminus ablation rates of 55 marine-terminating glaciers in Greenland over a ten-year period from 2013 to 2023. Terminus ablation rates were calculated using openly accessible data for terminus positions, surface elevation, bed elevation, and glacier speed to facilitate extension of the terminus ablation time series when more data becomes available. The results reveal significant spatial and temporal variability in terminus ablation rates, with distinct seasonal and interannual patterns observed. Three common variations in terminus ablation were identified, ranging from erratic seasonal cycles to consistent seasonal variations and large interannual fluctuations. The study also categorized glaciers into regions and examined the regional patterns of terminus ablation. Synchronicity between terminus ablation and discharge was observed, suggesting a significant link between seasonal terminus ablation change and discharge. However, differences in data resolutions were acknowledged as potential sources of variability. This research contributes to our understanding of the dynamic processes occurring at the termini of Greenland’s glaciers and their implications for ice sheet mass loss and sea-level rise.