How much has the Greenland Ice Sheet’s retreat accelerated over the last 35 years within the vicinity of the Jakobshavn Glacier, and how does the vicinity to the fast moving glacier impact retreat nearby?
The Greenland Ice Sheet retreat is a very clear and quantifiable metric by which climate change can be evaluated. Recent studies have suggested that the ice sheet will continue to contribute to sea level rise, meaning that mapping the future expectations for changes in the ice sheet are vital.
To quantify the retreat by area, the datasets were loaded into QGIS, and sections of the retreat were mapped by creating polygons. Four sets of polygons were made by hand: two sets of polygons for each of the sets of years of retreat.
Polygons marking the margin retreat for a) 1985-2001 North and South in yellow (left), margin retreat for b) 2001-2020 North and South in pink (right).
The interactive figure below shows the general results of the study. Horizontal bars indicate the retreat rates at different latitudes, and the area of the bars correspond to the area of each section of retreat.
The paramount importance of Jakobshavn Glacier retreat in driving the retreat of the land-based ice sheet margin is illustrated by the fact that the highest retreat rates between 2001 and 2020 occur in the vicinity of the fjord. The retreat rates at the margins of our study area, which are the furthest from Jakobshavn Glacier, are near zero within uncertainties.
This analysis indicated that the closer to the fast-moving marine outlet glacier, the faster the retreat rates. More generally, the retreat of the ice margin has accelerated significantly between the two periods. The vicinity to a glacier likely impacts the retreat rate of the ice sheet around it, specifically muting feedback such as ice-albedo feedback in areas far from the fjord, a factor which warrants further study due to its impact on the future modeling of glacial systems and predictions.