Proglacial landform assemblage in a rapidly retreating cirque glacier due to temperature increase since 1970, Fuegian Andes, Argentina

The general trend of glacial retreat since the Little Ice Age has shown an acceleration during the last decades in Southern Argentine and Chilean Patagonia. The Fuegian Andes climatic records report an irregular mean annual temperature increase since 1970, with acceleration from 2015, and the Chato...

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Bibliographic Details
Published in:Geomorphology
Main Authors: San Martín, Cristina Natalia, Ponce, Juan Federico, Montes, Alejandro, Díaz Balocchi, Luis Alfredo, Gorza, Candela, Coronato, Andrea Maria Josefa
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier Science
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Online Access:http://hdl.handle.net/11336/148713
Description
Summary:The general trend of glacial retreat since the Little Ice Age has shown an acceleration during the last decades in Southern Argentine and Chilean Patagonia. The Fuegian Andes climatic records report an irregular mean annual temperature increase since 1970, with acceleration from 2015, and the Chato Glacier, as other regional cirque glaciers, has undergone a rapid ice front retreat. A detailed mapping of the proglacial area of the Chato Glacier allowed the identification of a landform assemblage related to the glacier retreat during the last decades. In this paper morphological and sedimentological features of this peculiar landform assemblage, generated in an intense glacial ablation environment, are described and the causes of their origin are discussed. Among the most remarkable landforms annual moraines, hummocky moraines, esker-like landforms, flutes, kettle ponds, dirt cones, glacifluvial deposits, pronival ramparts and collapsed moraines are found. The multitemporal analysis of the Chato Glacier retreat allowed us to interpret that most of these landforms were generated when the landscape became ice-free after 2005. The Chato Glacier cirque floor gentle slope, the thin-ice thickness and the occurrence of a rocky threshold near the glacier front would have promoted the rapid glacier thinning and the disconnection of dead ice. This context, together with the sediments and meltwater availability, would have favored the development of this landform assemblage which is ephemeral due to its high susceptibility to erosion. Fil: San Martín, Cristina Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur. Instituto de Ciencias Polares, Ambientales y Recursos Naturales; Argentina Fil: Ponce, Juan Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones ...