Gravity Monitoring of Volcanoes

Abstract

The Earth's gravity field varies over time due to external and internal causes, but in minute proportions compared to its average value. The basic principle of microgravity monitoring is that changes in Earth's gravity can reflect deep mass transfer processes, often associated with surface deformation. Gravimetry measurements can be made either with relative gravimeters or with absolute gravimeters. The resolution and accuracy of absolute gravimeters are better than those of relative spring gravimeters. Most of the gravity monitoring measurements concern ground measurements on benchmarks. Microseismic activity can be due to both natural causes and anthropogenic. Hydrothermal systems manifest themselves at the surface in the form of fluids and temperature anomalies. Muography is a method based on corpuscular physics that has been developed for several decades for the study and monitoring of volcanoes.