Conductivity distribution beneath Socompa volcano, northwestern Argentina, from 3-D magnetotelluric characterization

Abstract

The Socompa volcano is one of the Holocene volcanoes of the Central Volcanic Zone of the Andes. Given that it records effusive activity after 5910 YBP and that recent studies reveal unrest associated with the uplift of its edifice, it is considered an active volcano. With the aim of explaining new features that provide information about the nature of its state, here we present a geoelectric structures model of the subsurface of Socompa volcano obtained with the magnetotelluric method. One of the main features defined by the 3-D model is a body with an electrical resistivity value lower than 10 Ωm between 2 and 7 km depth and located below the volcanic edifice. This body, interpreted as the magmatic heat source of the volcano, is connected to a shallow and thick high conductive layer that covers the surrounding area. Our results highlight a possible shallow magma reservoir below the Socompa volcano and an associated -active or not- hydrothermal system.