CNR and INGV researchers, through the use of radar images from the Japanese satellite ALOS 2, have detected the deformations of the ground caused by the seismic events of 26/10/2016 which hit the provinces of Macerata and Perugia. The deformation field detected extends for about 20 km in a northerly direction and has a maximum ground subsidence of about 18 cm (see figure below)
The activity relating to the study of ground deformations and seismic sources continues, now focused on the events of last October 26th. This activity is coordinated by the Civil Protection Department (DPC) and is carried out by a team of researchers from the Institute for Electromagnetic Sensing of the Environment National Research Council (CNR-IREA of Naples) and the National Institute of Geophysics and Volcanology (INGV), centers of expertise in the fields of satellite radar data processing and seismology, with the support of the Italian Space Agency (ASI).
"Using data from the Japanese satellite ALOS 2, the team of researchers from CNR-IREA and INGV measured with high precision the permanent movements of the ground originating during the earthquake, using differential interferometry", explains Riccardo Lanari , director of the CNR-IREA. “In this case, the frequency band used (L band) by the radar operating on board the ALOS 2 satellite allowed us to detect ground deformations despite the affected area being particularly covered by vegetation. These deformations occur about 8 km further north, compared to the deformations caused by the Amatrice earthquake of 24 August and characterize an area that extends for about 20 km in a northerly direction and has a maximum ground subsidence of about 18 cm (corresponding to 22 centimeters away from the radar line of sight) in the Vallestretta area”.
“The ground movements measured by the satellite, together with other geological and seismological data, are now being analyzed to develop physical-mathematical models through which it will be possible to identify the source fault of the earthquake and characterize its deep activity. The first results seem to indicate that the fault activated on October 26 is part of the same geological structure that caused the Amatrice earthquake. The fault plane is therefore inclined towards the west by about 50°, is between 10 and 3 kilometers deep, and does not reach the surface”, explains Stefano Salvi, INGV technologist manager. "Since the Colfiorito sequence in 1997, radar satellite data has been used many times in Italy to identify seismic and volcanic sources, also thanks to the techniques developed by CNR-IREA researchers, who are today at the forefront on the international scene".
The objective of the Civil Protection Department, during a seismic emergency, is to quickly obtain a picture of the deformations and displacements of the ground caused by the earthquake in the epicenter area.
The CNR-IREA and INGV Competence Centres, thanks to their specific skills, support the Department in the use of satellite data and information and in their integration with in situ data: this collaboration allows the development of products, methods and procedures that improve the national emergency response system and are available to the entire National Civil Protection Service
