Glacier retreat from the Little Ice Age to the year 2020 in the eastern sector of the Fuegian Andes, Tierra del Fuego, Argentina

Abstract

We evaluate area change of small cirque glaciers in the Argentine sector of the Fuegian Andes, from moraines mapping, aerial photography (1970 and 1988), Landsat 5 (2000 and 2010), Landsat 8 (2015) and Sentinel (2020) satellite imagery. Changes in glacier area were compared to temperature and precipitation data from ERA5 over the period 1950–2020. Our results show a strong relation between glacial retreat and changes in air temperature. Collectively, the glaciers shrank by 70% from positions achieved during the Little Ice Age (~1870). Half of this glacial retreat (total glacier area loss equaled 3.8km2 ) occurred after 1960–1970 when an increase of approximately 1°C in the mean annual temperature was recorded in the area. We observe a rapid increase in the rate of area loss and glacial retreat speed after 2015, with average values of 0.010km2 yr−1 and 30m/year, respectively, in concert with a rapid rise of observed air temperature (approximately 0.7°C). The intensification of the Southern Westerlies Winds (SWW) at this latitude, related to the positive trend in the Southern Annular Mode (SAM), produced an increase in temperature and decrease in precipitation in this sector which has induced a continuous and rapid glacial retreat since almost 1970.