New structural, hydrogeological and hydrothermal insights on Cumbre Vieja (La Palma, Canary Islands, Spain).

Abstract

Determining the link between pre-existing structures and volcanism is a topic of interest in Volcanology. We carried out a geophysical study (self-potential) devoted to the characteriza- tion of the major structural limits influencing the hydrogeological pattern in La Palma (Canary Islands) and its relationship with the most recent volcanism of this island. Since 1 Ma volcanic activity has concentrated at the southern half of the island, on the Cumbre Vieja volcanic rift-zone. During the 1949 eruption a N-S fault system, facing west, de- veloped in the summit area of Cumbre Vieja. This was interpreted as the surface expression of an incipient deformation zone on the western flank (Day et al., 1999). We use self-potential measurements to provide new information to characterize and locate the limits guiding upward or downward fluid circulation and possibly associated to future flank failures and potential landslides on the Cumbre Vieja rift-zone.