2020 Dickinson Sydkap Hackweek: Sixty year record of ice area loss from the marine terminating Sydkap Glacier, southern Ellesmere Island, Nunavut, Canada
Abstract
Sydkap Glacier forms the main marine terminating outlet of Sydkap Ice Cap (76°39'40.2"N 85°13'45.7"W), which flows into South Cape Fiord. With a length of 33.2 km in 2019, understanding the progression and rate of loss of this glacier is important for quantifying regional patterns of glacier retreat, predicting iceberg production into Baffin Bay, and understanding how climate change is affecting glaciers in the Canadian Arctic Archipelago. In this study, we present the first detailed analysis of changes in Sydkap Glacier 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. Terminus outlines were manually digitized in QGIS from georectified air photos and true-color pan-sharpened composites of Landsat imagery. Area lost to calving was calculated by differencing the oldest terminus with subsequent years, producing a total area loss of 36.41 km2 between 1959 and 2019. This included area loss rates of 0.505 km2 a-1 from 1959-1972, 19.91 km2 a-1 from 08/1972-08/1973, 0.177 km2 a-1 from 08/1973-2006, 0.511 km2 a-1 from 2006-2011, 0.332 km2 a-1 from 2011-2015, and 0.047 km2 a-1 from 2015-2019. The average dynamic discharge for the last decade is 0.055 ± 0.0029 Gt a-1, with a mean thickness of 156 m at the terminus, calculated from ITS LIVE and GlaThiDa observations. We hypothesize the rapid period of change between 1972 and 1973, when the 54.69 percent of the total area loss occurred, was prompted by the terminus retreating from a pinning point formed by a delta on the eastern side of South Cape Fiord and an outlet glacier on the western side of the fiord. This was the highest retreat rate determined in our study by almost two orders of magnitude.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMC038.0004S
- Keywords:
-
- 0720 Glaciers;
- CRYOSPHERE;
- 0758 Remote sensing;
- CRYOSPHERE;
- 0762 Mass balance;
- CRYOSPHERE;
- 0798 Modeling;
- CRYOSPHERE