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On August 24, 2016, at 01:36 UTC a ML 6.0 earthquake struck a portion of the Central Apennines between the towns of Norcia and Amatrice. The epicentre was located near the town of Accumoli. Prompt Synthetic Aperture Radar (SAR) acquisitions and the available scientific knowledge of the area allowed to elaborate a first interpretative framework of the ongoing seismic sequence only 30 hours after the mainshock (doi: 10.5281/zenodo.60938) and a second analysis, complete of several Interferometric SAR (InSAR) data within two weeks (doi: 10.5281/zenodo.61682). Through the inversion of InSAR data, we found that the seismogenic structure is oriented NNW-SSE and extends about 20 km between the towns of Norcia and Amatrice with a width of about 10 km. The retrieved slip reaches a maximum value of more than 1.2 m, and stops at a depth of about 4 km. Preliminary fault slip inversions suggest two main patches of co-seismic deformation located NW and SE of the hypocenter. As a final result, we highlight the double fold achievements obtained: a rapid fault identification, and no disadvantage in terms of reliability of the retrieved parameters.

On May 20, 2012, at 02:03 UTC, a moderate earthquake of local magnitude, Ml 5.9 started a seismic sequence in the central Po Plain of northern Italy The mainshock occurred in an area where seismicity of comparable magnitude has neither been recorded nor reported in the historical record over the last 1,000 years. The aftershock sequence evolved rapidly near the epicenter, with diminishing magnitudes until May 29, 2012, when at 07:00 UTC a large earthquake of Ml 5.8 occurred 12 km WSW of the mainshock, starting a new seismic sequence in the western area; a total of seven earthquakes with Ml >5 occurred in the area between May 20 and June 3, 2012. Immediately after the mainshock, the Italian Department of Civil Protection requested the Italian Space Agency to activate the Constellation of Small Satellites for Mediterranean Basin Observation (COSMO-SkyMed) to provide Interferometric Synthetic Aperture Radar (InSAR) coverage of the area. COSMO-SkyMed consists of four satellites in a 16-day repeat-pass cycle, with each carrying the same SAR payload. In the current orbital configuration, within each 16-day cycle, image pairs with temporal baselines of 1, 3, 4 and 8 days can be formed from the images acquired by the four different sensors. Combined with the availability of a wide range of electronically steered antenna beams with incidence angles ranging from about 16˚ to 50˚ at near-range, this capability allows trade-offs between temporal and spatial coverage to be exploited during acquisition planning. A joint team involving the Istituto Nazionale di Geofisica e Vulcanologia (INGV) and the Istituto per il Rilevamento Elettromagnetico dell'Ambiente (IREA-CNR) was activated to generate InSAR-based scientific products to support the emergency management. In this framework, the ASI and DPC requested that INGV activated the Space-based Monitoring System for Seismic Risk Management (SIGRIS). SIGRIS consists of a hardware/software infrastructure that is designed to provide the DPC with value-added information products in the different phases of the seismic cycle. During earthquake emergencies, its goal is to rapidly provide decision-support products, such as validated ground-displacement maps and seismic source models. This study reports the details of the activation of the SIGRIS system in the case of the Emilia sequence. It provides a description of the COSMO-SkyMed datasets and processing procedures, as well as selected interferometric results for the coseismic and post-seismic ground deformation. […]