The submerged footprint of Perito Moreno glacier

LODOLO, EMANUELE; DONDA, FEDERICA; LOZANO, JORGE; BARADELLO, LUCA; ROMEO, ROBERTO; BRAN, DONALDO M.; TASSONE, ALEJANDRO

Scientific Reports

Nature Publishing Group

Lugar: Londres; Año: 2020 vol. 10

PeritoMoreno is the most famous calving glacier of the South Patagonia Icefield, thelargesttemperate glacier system of theSouthern Hemisphere. Unlike most of the glaciers in the regionthat have strongly retreated in recent decades, theposition of perito Moreno glacier front remainedrelatively unchanged in the last century. However,earliest photographic documents show that, at theend of the nineteenth century, the front was ca. 800m behind the current position. There is no reliableinformation about the positions ofthe perito Moreno front in earlier times. Here we show evidenceof two subaqueous moraine systems both in the canal deLos témpanos and in the Brazo Rico, thetwo arms of Lago Argentino alongwhich Perito Moreno glacier has flowed over time. These moraines,identified for the first time in the Canal de LosTémpanos from bathymetric and high-resolution seismicprofiles, mark the position of the largest glacieradvance, tentatively correlated with the moraines ofthe ?Herminita advance? identified and dated onland. Weinterpret these bedforms as the evidenceof the most pronounced advance of Perito Moreno glacierduring the mid-Holocene cooling eventthat characterized this sector of theSouthern Hemisphere. this study highlights the importance ofsubaqueous glacial bedforms, representing decisiverecords of the glacial history and palaeoclimate,which could help unveiling the originof the different behavior of glaciers like Perito Moreno that in awarming climate are relativelystable.