Submerged morphologies in Punta Banderas, Lago Argentino, Patagonia

JORGE GABRIEL LOZANO; FLORENCIA B. RESTELLI; DONALDO M. BRAN; YASMIN S. GUTIERREZ; ALEJANDRO A. TASSONE

S.C. BARILOCHE

Congreso; IAL - IPA 2022; 2022

CONICET

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 ischaracterized by the presence of the most emblematic glacier of the region, the PeritoMoreno glacier. Whereas most of the Lago Argentino outlet glaciers underwentconsiderable ice mass loss and retreated during the last 80–100 years, Perito Morenoglacier shows an apparent anomalous behavior and may be regarded as having beenstable since 1920. The periodic advances of the Perito Moreno glacier’s front form anatural ice dam as it progresses across the rocky shore of the Magallanes Península. Thisevent blocks the water flow from Brazo Rico towards the Canal de los Tempanos, allowingthe 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 armshosting Perito Moreno glacier. High-resolution seismic profiles, complemented withbathymetric profiles, have allowed to map the whole lake floors of Brazo Rico/Brazo Surand the southern part of Canal de Los Témpanos, and to identify the mainseismostratigraphic units within the glacio-lacustrine cover. A new data set of highresolution seismic profiles located northern of Puerto Banderas has been analyzed. A fewsubmerged morphologies identified as the continuation of onland moraines has beenrecognized, 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 widearea of the Lago Argentino system.