Hydraulic pressure variations of groundwater in the Gran Sasso underground laboratory during Amatrice earthquake of August 24th, 2016

Since May 2015, hydraulic pressure, temperature and electrical conductivity of groundwater are in continuos recording near the deep underground laboratories of Gran Sasso of INFN. We used the S13 borehole that have pressure varying in the range of 24-28 bar during the year; these values mean that we have at least 300 m of water table above. The sampling of these parameters was brought until to 50 Hz using a 3 channels 24-bit ADC. During the period May 2015 – September 2016 (17 months) we detected hydraulic pressure signals from 12 earthquakes at different surface distances (from 12.000 to 30 km) and different magnitudes (from 8.3 to 4.3 Mw). For the Amatrice mainshock, we present, as first results, the hydroseismograph recorded at the S13 hydraulic pressure device compared to the time history recorded at GIGS station located both in the deep core of the Gran Sasso chain.