Figure 11

Number of negative micropulses (red line) each hour from 19 August (doy 232) to 2 September 2016 (doy 246), while the blue line shows the integral trend in arbitrary scale, black vertical line represents the Amatrice earthquake occurrence and green horizontal line is the zero level. In the period from May 2015 to July 2016 we did not observe any negative micropulses.