Surface Elevation Change of Glaciers Along the Coast of Prudhoe Land, Northwestern Greenland From 1985 to 2018. Issue 11 (9th November 2021)

• Record Type: Journal Article
• Authors: Wang, Yefan; Sugiyama, Shin; Bjørk, Anders A.
• Is Part Of: Journal of geophysical research. Volume 126:Issue 11(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-09
• Subjects: northwestern Greenland -- glaciology -- tidewater glaciers -- elevation changes; Geomorphology -- Periodicals; 551.3
• DOI: 10.1029/2020JF006038
• Languages: English
• ISSNs: 2169-9003

Abstract

Abstract: Outlet glaciers in Greenland exhibited rapid frontal retreat, thinning, and flow acceleration in the 21st century. In contrast to a number of studies in the last two decades, long‐term glacier changes are not well known, hence limiting the understanding of ongoing glacier retreat. In this study, we present surface elevation changes of 16 glaciers along the coast of Prudhoe Land, northwestern Greenland, using digital elevation models between 1985 and 2018. All the glaciers experienced surface lowering at a mean rate of −0.55 ± 0.24 m a −1 over the period of study. Surface elevation change has shown a clear shift from 0.14 ± 0.17 m a −1 in 1985–2001 to −1.31 ± 0.20 m a −1 in 2001–2018. Thinning after 2001 was more significant at the glaciers terminating in Inglefield Bredning, represented by the most rapid thinning of Tracy and Farquhar Glaciers at −3.91 ± 0.13 and −2.91 ± 0.18 m a −1, respectively. Glaciers terminating in shallower fjords directly connected to Baffin Bay showed a thinning rate 40% slower than those in the Inglefield Bredning region. Warming trends in atmospheric and ocean temperature since the late 1990s are most likely triggers of the glacier regime shift around 2001. The heterogeneity in the glacier change is attributed to the glacier geometry and fjord bathymetry of each individual glacier, since glaciers terminating in deep fjords are subjected to greater acceleration and are more affected by deep ocean warming. Plain Language Summary: Ice mass loss from the Greenland Ice Sheet accounts for approximately 20% of sea‐level rise since 1990s. The mass loss is not totally due to glacier surface melt, but a considerable amount of ice is lost as a result of submarine melting and calving at the fronts of marine‐terminating glaciers. To measure mass loss of 16 glaciers along the coast of Prudhoe Land in northwestern Greenland, we analyzed surface elevation from aerial photographs taken in 1985 with recent data acquired by satellite remote sensing. Glaciers in this region are rapidly changing, but studies are sparse and limited to the recent period. Our results showed rapid thinning of the glaciers in the 21st century in contrast to minor changes in 1985–2001. Most likely, atmospheric and oceanic warming triggered the change after 2001. The magnitude of thinning showed significant variations among the glaciers. Large and deep glaciers feeding Inglefield Bredning thinned most rapidly, while changes were smaller at glaciers terminating in narrow fjords on Baffin Bay. Thinning rate was controlled by the fjord width and bathymetry. These results help our understanding of the mechanisms driving the mass loss of the Greenland Ice Sheet and its contribution to sea level rise. Key Points: Surface elevation change is quantified for 16 glaciers along the coast of Prudhoe Land in northwestern Greenland from 1985–2018 Glaciers thinned rapidly from 2001–2018 after a relatively stable period from 1985–2001 Atmospheric and oceanic forcing triggered the thinning after 2001, with heterogeneity controlled by fjord depth and glacier width