ANALYSIS OF 20-YEAR TERRESTRIAL GRAVITY AND GROUND DEFORMATION CHANGES COLLECTED AT MT. ETNA: COMPARISON WITH SATELLITE DATA

Abstract

We present a preliminary comparison between satellite and terrestrial gravity and GNSS data collected in a twenty-year period (2002-2022) at Mt. Etna volcano, with the aim of investigating the capabilities of this integrated approach to study the dynamics of volcanic phenomena over time-scales of months to years. The terrestrial gravity data were collected through absolute and relative spring gravimeters in the framework of almost monthly campaigns. Instead, GNSS measurements are continuously collected for monitoring purposes. Regarding satellite data, we used the Gravity Recovery and Climate Experiment (GRACE) data and GRACE Follow-On L3 solutions, that can provide high-quality information about mass distribution at regional and global scales in a long-term interval. After being corrected for the known effects, reduced terrestrial gravity and GNSS height variations were compared with satellite data. The comparison reveals long-term correlations between the analyzed time series which could represent volcano-scale variations.