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Call for Papers for the semi-thematic N° 67: (Re)defining rural territories, between the global South and North: actors, processes, scales.

Full papers are invited to be submitted via the journal's official platform by 15 March 2024.

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Analysis of the mass movement of quebrada blanca: implicances in the geomorphological and cryogenic dynamic. Upper elqui river basin

Authors

  • Pablo Rodrigo Iribarren Anacona Unidad de Glaciología y Nieves. Dirección General de Aguas. Santiago

Abstract

A complex mass movement was studied in the upper Elqui River basin with the aim of identify the triggering factors and interpret they relation with the actual geomorphic, cryogenic and climatic dynamic. Throughout the analysis of satellite images, aerial photos and field work were calculated some geomorphological parameters of this event and was possible estimate the approximate age of this phenomenon. The rotational landslide and associated debris flow was occurred between the years 1987-1988, affected an area of 0.22 km² and mobilized an approximated material volume of 2.4-3.2x106 m³. The run up of deposits between 15 and 50 meters indicates that the debris flow would have reached maximum speeds of 31 m/s in the contact with the rock glaciers of the zone. In this sense is outlined the important role that can play the thaw in snowy years in the genesis or evolution of the mass movements and the utility of the meteorological information, the seismic catalogues and the historical satellital images in geomorphological back analysis. Finally it is outlined the role of rock glaciers as regulatory agents of the debris transport in high mountain areas and the importance of large magnitude and low frequency phenomena, like the mass movement analyzed, in the debris supply of these landforms.    

Keywords:

Elqui River, mass movement, periglacial belt, debris supply, rock glacier