Characterizing Hydrothermal Systems Using Gravitational Methods
Antonina Calahorrano-Di Patre1, J. Salgado2, M. Córdova2, M. Almeida2, P. Mothes2, M. Battaglia1,3
Affiliations: 1 University of Rome – La Sapienza, Italy; 2 Instituto Geofísico de la Escuela Politécnica Nacional, Ecuador; 3 Volcano Disaster Assistance Program, USGS, USA
Presentation type: ECR Invited talk
Presentation time: Thursday – 03.07.25, 11:40 - 12:05, Room R380
Abstract
The existence of hydrothermal systems in active volcanoes is usually a source of uncertainty in eruption forecasting. Although movement of fluids within volcanoes can be monitored through several techniques, such as seismic signals, the response of magmatic and hydrothermal fluids are often confused, posing a non-trivial problem when evaluating the probability of future activity. Moreover, characterizing the extension and location of the hydrothermal system is crucial to better understand the hazards from a potential eruption, due to an increase in explosivity caused by the interaction between magma and hydrothermal fluids. Gravitational methods are the only technique capable of characterizing mass changes beneath the surface. In combination with other geodetic and geophysical techniques, gravity can monitor and characterize changes in a volcano’s hydrothermal system, being capable to discriminate between higher density (such as magma) and lower density fluids. Focusing on the case of Cotopaxi, one of the most hazardous glacier clad stratovolcanoes of Ecuador, we show how gravity monitoring has helped characterize the changes in Cotopaxi’s hydrothermal system before and after two recent eruptive periods (2015 and 2022), the insights gained about magma-water interaction in this system, as well as the impact on forecasting.