Submerged morphologies in Punta Banderas, Lago Argentino, Patagonia”

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

Bariloche

Congreso; IAL IPA Joint Meeting 2022; 2022

International Association of Limnogeology

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 characterized by 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 mass loss and retreated during the last 80–100 years, Perito Moreno glacier shows an apparent anomalous behavior and may be regarded as having been stable since 1920. The periodic advances of the Perito Moreno glacier’s front form a natural ice dam as it progresses across the rocky shore of the Magallanes Península. This event blocks the water flow from Brazo Rico towards the Canal de los Tempanos, allowing the rise of the water level. As the ice-dam collapse, the water outburst occur in semi-periodically events. Between November 2017 and December 2019, the IGeBA (CONICET-UBA, Argentina) and OGS (Italy) performed several geophysical surveys in the lake arms hosting Perito Moreno glacier. High-resolution seismic profiles, complemented with bathymetric profiles, have allowed to map the whole lake 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 new data set of high resolution seismic profiles located northern of Puerto Banderas has been analyzed. A few submerged morphologies identified as the continuation of onland moraines has been recognized, in addition with mass-wasting deposits and erosive features within the sedimentary record. The integration of the analysis of these morphologies, along with the previous results of our group, allowed the development of an evolution model of a wide area of the Lago Argentino system