Quebrada Survey south of Arica, Chile

Abstract

The Quebradas, south of Arica, Chile are wide, steep-sided valleys that trend east-west from the Andes mountains down to the sea. The Andes receive annual precipitation, which is transported through the Atacama Desert, one of the driest places on Earth, by the Quebradas, to the coast where fog is common due to the Humbolt current upwelling. The only source of water for the Quebradas is in the upper catchments, and therefore their walls have been affected by very few 'wet' processes since their initial incision. This fieldwork forms part of a funded Leverhulme project, in which we use the topographic signature of dry landscapes on the Moon and wet landscapes on Earth to investigate what role water has played in shaping Mars’ surface. The Quebradas are a dry terrestrial example in a larger dataset, comprising other desert environments and humid alpine and arctic areas. We have now characterised the topography of these Quebrada hillslopes using satellite images and structure from motion photography to generate elevation models at 2 m/pix and 0.5 m/pix respectively.