This study is focused on wide-area deformation monitoring initiatives based on the differential interferometric SAR technique (DInSAR). In particular, it addresses the use of advanced DInSAR (A-DInSAR) techniques, which are based on large sets of synthetic aperture radar (SAR) and Copernicus Sentinel-1 images. Such techniques have undergone a dramatic development in the last twenty years: they are now capable to process big sets of SAR images and can be exploited to realize a wide-area A-DInSAR monitoring. The study describes several initiatives to establish wide-area ground motion services (GMS), both at county- and region-level. In the second part of the study, some of the key technical aspects related to wide-area A-DInSAR monitoring are discussed. Finally, the last part of the study is devoted to the European ground motion service (EGMS), which is part of the Copernicus land monitoring service. It represents the most important wide-area A-DInSAR deformation monitoring system ever developed. The study describes its main characteristics and its main products. The end of the production of the first EGMS baseline product is foreseen for the last quarter of 2021.

This paper documents evidence of surface faulting associated with the 6 April 2009 moderate-sized earthquake (ML 5.8, Mw 6.3) in the central Apennines of Italy, which caused major damage to the town of L’Aquila and its surroundings. Coseismic surface ruptures were mapped for a minimum distance of 2.6 km along the Paganica fault, a fault still poorly investigated relative to the other active faults nearby, which bound much wider range fronts. Surface rupture length (SRL) and maximum displacement parameters (2.6 km minimum and 10–15 cm, respectively) are in agreement with what is expected for an Mw 6.3 event in the Italian Apennines tectonic environment. Different viewpoints exist on the amount of SRL and the number of activated faults. We propose a pattern of sympathetic and secondary slip on an array of faults around the master seismogenic structure. Past seismicity and evidence for larger Holocene offsets on this and other capable faults nearby prove that the 2009 event is not a good reference event for assessing the seismic hazard of the region. Nevertheless, the 2009 L’Aquila earthquake once more confirmed the importance of detailed geological studies for a proper seismic hazard assessment, and it clearly illustrates the need to pay attention to moderate events and supposedly minor active faults. Indeed, this type of earthquake is rather frequent in the whole Mediterranean region and is potentially much more destructive than in the past, due to the expanding urban centers and infrastructures inside their epicentral regions and even right above the traces of capable faults