Submerged morphologies in Punta Banderas, Lago Argentino, Patagonia

LOZANO, JORGE GABRIEL; RESTELLI, FLORENCIA; BRAN, DONALDO MAURICIO; GUTIERREZ, YASMIN S.; TASSONE, ALEJANDRO

Bariloche

Congreso; IAL-IPA 2022 Lakes, Memories of the Landscape; 2022

Lago Argentino is located in the Santa Cruz province, Argentina, between 50 to 50.5º S,next to the city of El Calafate. It is one of the largest Patagonian lakes, and is characterizedby the presence of the most emblematic glacier of the region, the Perito Moreno glacier.Whereas most of the Lago Argentino outlet glaciers underwent considerable ice massloss and retreated during the last 80–100 years, Perito Moreno glacier shows an apparentanomalous behavior and may be regarded as having been stable since 1920. The periodicadvances of the Perito Moreno glacier’s front form a natural ice dam as it progresses acrossthe rocky shore of the Magallanes Península. This event blocks the water flow from BrazoRico towards the Canal de los Tempanos, allowing the rise of the water level. As the ice-damcollapse, the water outburst occurs in semi-periodically events. Between November 2017and December 2019, the IGeBA (CONICET-UBA, Argentina) and OGS (Italy) performedseveral geophysical surveys in the lake arms hosting Perito Moreno glacier. High-resolutionseismic profiles, complemented with bathymetric profiles, have allowed to map the wholelake floors of Brazo Rico/Brazo Sur and the southern part of Canal de Los Témpanos,and to identify the main seismostratigraphic units within the glacio-lacustrine cover. A newdata set of high-resolution seismic profiles located northern of Puerto Banderas has beenanalyzed. A few submerged morphologies identified as the continuation of onland moraineshas been recognized, in addition with mass-wasting deposits and erosive features within thesedimentary record. The integration of the analysis of these morphologies, along with theprevious results of our group, allowed the development of an evolution model of a wide areaof the Lago Argentino system