Monitoring freshwater calving glaciers of the Southern Patagonia icefield by remote sensing and field instrumentation

A. RIVERA; OTROS 13; GABRIELA LENZANO, M.; L. LENZANO

Congreso; 27th IUGG General Assembly; 2019

The Southern Patagonia icefield (SPI) is the biggest ice mass of southern hemisphere outside Antarctica. Due to strong ice thinning, areal reduction and ice flow acceleration, the SPI is the principal South American contributor to sea level rise. Most of the SPI glaciers are calving into fjords or lakes where the complex interplay between ocean or fresh waters and the ice terminus is governing glacier dynamic behavior. The inner fjords where glaciers are ending at present are deep enough for glacier fronts to be near buoyancy. Under this condition, temperate glaciers like the ones of the SPI have ice fronts vulnerable to collapse, especially when ice accelerates and experience longitudinal stretching resulting in dynamic thinning. Recent improvements in availability, resolution and frequency of satellite imagery have supported a great advance on Patagonian glacier?s knowledge. However, there are several aspects explaining glacier behavior that are very poorly known. These variables require a great effort of field instrumentation and on the ground surveys. Here, we present the results obtained by our network of instruments installed nearby the main calving glaciers of the SPI, including terrestrial photographic cameras, water level pressure sensors and automatic weather stations. These installations are complemented with surface topography data collected by terrestrial and airborne Lidar, ice thickness obtained by on-the-ground and airborne radar, and lake water and sediment depths by seismic and sonar systems. Among the most striking results could be mentioned new lake bathymetries of up to 650 m in fjords recently abandoned by fast flowing glaciers.