First comparison of subsidence/uplift rates between Copernicus European Ground Motion Service data and long-term MIS 5.5 geological record in Mediterranean regions

Abstract

The European Ground Motion Service (EGMS), a component of the Copernicus Land Monitoring Service, offers a valuable tool for investigating vertical ground motion in coastal regions that are subject to different natural and anthropogenic processes. To conduct effective coastal assessments, it is essential to consider the multiscale interactions of these processes. This review presents a methodology for comparing EGMS Ortho (Level 3) data, based on Sentinel-1, and calibrated with measurements from the Global Navigation Satellite System (GNSS) and long-term rates based on the markers of the Marine Isotope Stage (MIS 5.5; Late Pleistocene). This study examines the Italian and Greek coasts, encompassing a range of geodynamic settings. In stable crustal segments, such as Sardinia, the EGMS Ortho (Level 3) data roughly align with both GNSS and post-MIS 5.5 rates. However, long-term based observed variations are considerably below the current 1 mm/yr EGMS precision. Conversely, in foreland basins, EGMS maps show higher values than GNSS data, which reflect regional interactions between ongoing tectonics and compaction. Local discrepancies between EGMS and GNSS in industrialized areas are attributable to industrial activities, as evidenced by the EGMS subsidence rates (8 mm/yr) observed in Ravenna, which exceed regional long-term estimates (0.8 mm/yr). In seismically active regions, such as Calabria and Sicily (e.g. the Messina Strait), the data reveals complex short- and long-term interactions linked to the seismic cycle. Conversely, in volcanic areas, like Campi Flegrei, Mt. Etna, Santorini and Nisyros, the EGMS data proves most valuable for highlighting complex volcano-tectonic movements. The findings of this study can be extended to other areas worldwide.