C038-0002
2020 Dickinson Hackweek: Evidence for Terminus Advance from a Piedmont-type Glacier along the Southeastern Edge of Sydkap Ice Cap, Ellesmere Island, Nunavut, Canada

Friday, 11 December 2020
Poster
Patrick Kissell Noonan1, Benjamin R Edwards2, William Hardy Kochtitzky3, Luke Copland4, Celine Nour Ghattas Smith5, Will Bresnahan6, Isabel Ruff1, Kaelan Felknor-Edwards5 and Hiba Aoid1, (1)Dickinson College, Carlisle, PA, United States, (2)University of East Anglia, Carlisle, PA, United States, (3)University of Ottawa, Ottawa, Canada, (4)University of Ottawa, Ottawa, ON, Canada, (5)Carleton College, Northfield, MN, United States, (6)Hamilton College, Clinton, MA, United States
Abstract:

Sydkap Ice Cap (76°39'40.2"N 85°13'45.7"W) is the largest of the 158 glaciers and ice caps that still exist on the southcentral and southwestern parts of Ellesmere Island, in Nunavut, Canada. While 92 percent (146) of those 158 decreased in area between 1974 and 2019, 12 have either expanded in area or remain unchanged. Eleven of those 12 are outlet glaciers to Sydkap Ice Cap. In this study we present the first detailed description of an advancing, piedmont-style glacier along the southeastern edge of Sydkap Ice Cap from analysis of archival aerial photography (1959) and satellite imagery (Landsat 1-8), including images from the years 1972, 1973, 1974, 1987, 1993, 1998, 2001, 2006, 2011, 2015, and 2019. To quantify terminus advance, we manually digitized the glacier terminus in QGIS from georectified air photos and true-color pan-sharpened composites of Landsat imagery. The glacier fills a valley that drains into the western side of South Cape Fiord, and dams a small lake (3 km2 on 14 Aug 2015) on its southwestern flank. Between 1959 and 2019, the terminus area increased by about 28.42 percent (2.585 km2 +/- 0.2535 km2) primarily eastward and southward. Of the six periods examined spanning the past 60 years, the glacier has consistently expanded during 5 of those 6 periods for an overall average rate of area increase of 0.034 km2 a-1. But, since 2006 this rate has decreased by almost an order of magnitude from an average rate of 0.050 km2 a-1 (+/- 0.033 km2 a-1) from 1959 to 2006, to 0.001 km2 a-1 (+/- 0.044 km2 a-1) between 2006 and 2019. At present we are uncertain as to why this glacier has been expanding in area for 46 of the past 60 years.

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