Inferring Glaciological Attributes of Thwaites Glacier Using GPS-Interferometric Reflectometry and Precise Point Positioning

• Main Author: Matheny, Peter Ogden
• Format: Text
• Language: unknown
• Published: University of Memphis Digital Commons 2019
• Subjects: GPS; Antarctica; Amundsen Sea; Thwaites Glacier; Antarc*
• Online Access: https://digitalcommons.memphis.edu/etd/1982; https://digitalcommons.memphis.edu/context/etd/article/3090/viewcontent/6412.pdf

We use two continuous GPS stations located on Thwaites glacier to estimate the rate of snow accumulation through GPS interferometric reflectometry and separately examine details of the motions of the glacier. We find an 8-year snow accumulation rate in meters water equivalent for the station Upper Thwaites of 0.44±0.03 m.w.e./yr and a 7-year rate for the station Lower Thwaites of 0.56±0.06 m.w.e./yr. Averages at both GPS sites match the European Centre for Medium-Range Weather Forecasts reanalysis accumulation rate, derived from integrated snowfall over the same period. We used precise point positioning to obtain daily station positions and modeled the observed movement of the glacier towards the Amundsen Sea using a constant acceleration and periodic fluctuations about this background motion. Lower Thwaites exhibits statistically significant deviations from this model that may be related to emptying and refilling of a nearby subglacial lake.