Alemania Glacier Retreat, Lago Martinic expansion-contraction, Chile

The Cordillera Darwin in Tierra Del Fuego Chile is a remote area. GLIMS (Glacier Land Ice Monitoring from Space) which has an inventory of glaciers showing at least size and boundaries, has nothing for this region in 2012. The USGS in their publication on South American glaciers just notes the lack of satellite imagery for assessing these remote glaciers. Chile is currently undertaking an inventory of these glaciers. The Alemania Glacier (Roncagli) is the focus of this post, the glacier can be seen from the Beagle Channel. The focus is not main terminus, but the terminus that ends in Lago Martinic (LM). In Google Earth imagery imagery this lake is trapped by the Alemania Glacier. There are two smaller glacier draining into the west end of the lake and Alemania’s secondary terminus ends in the lake. The red arrow points to the terminus, the green arrow to a nunatak near the Lago Martinic terminus and the yellow arrow to a developing nunatak upglacier, AT indicates the main terminus of the Alemania Glacier. The next three images are all from Landsat and indicate some spectacular changes from 2000 top image, 2008 middle image and 2011 bottom image. From 2000 to 2008 the Lago Martinic terminus of the glacier retreat 1300 meters, reaching the nunatak by 2008, this represents a significant expansion of the lake. In 2011 the terminus has retreated little but the lake has drained to an extent exposing the pink areas of the former lake bottom. In the future this maybe a lake that periodically fills in the Austral Spring and drains later in the Austral summer. The main terminus of the Alemania Glacier also exhibits a notably developing lake at the terminus compared to 2000, more on this below. The upglacier nunatak, yellow arrow, has also become more exposed indicating glacier thinning. A closeup of the main terminus of the Alemania indicates a 500 meter retreat of the east side of the glacier from the 2000 GE imagery to the 2011 Landsat imagery. The lake at the terminus has become significant, this should speed retreat in the near future. Though further south than the large Patagonia Icefields the glacier changes mirror those of the main icefields, Colonia, Tyndall, Gualas that are being intensively investigated by the Chilean Laboratorio de Glaciologia

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