Estudio de las condiciones del techo del permafrost y de la capa activa del terraplén de asentamiento del Museo Otto Nordenskj?ld, Isla Cerro Nevado, Antártida

摘要

Study of current conditions of the active layer and top of permafrost of the embankment under the Otto Nordenskj?ld Museum, Cerro NevadoIsland, AntarcticaThe Otto Nordenskj?ld hut was built in Cerro Nevado Island, Antarctica, in 1902. It was named as Historic Site and Monument No. 38 by the AntarcticTreaty and as National Historic Monument by a decree of the Argentinian government (07/26/1965). For this, Argentina must preserve the hut from thenatural deterioration which is subject. In this work, a topographical survey is conducted together with the assessment of the mitigation techniques usedin the area from 1980 to the present in order to prevent permafrost degradation under the museum. Besides, the thermal regime and the spatialdistribution of the active layer and the top of permafrost and their interaction with different topographic variables are analyzed. The studies conducted inthe area showed the close surface location of the frozen ground favours the surface subsidence by melting of the underground ice. This phenomenoncreates concavities where the snow is trapped. When it is melted, it transfers heat to the environment increasing shallow frozen ground degradation.These processes occur near the hut Otto Nordenskj?ld Museum, so a fast intervention was necessary. Prevention works were made by MUSEOANTARprogram during the 2014-2015 Antarctic summer fieldwork and they were focus on the NE-SW embankment slope according to the achieved results.Vertical sheet piles and horizontal gabions were used to fill the depressions with sediments of different grain size in order to raise the average level of thesurface, smooth all sites of snow accumulation and promote cold air circulation.