As on the previous two days, seismic activity was slightly down by the evening of July 23, 2013, with the strongest quake having a magnitude of 1.7. More than 550 microearthquakes have been recorded in total.
In parallel to the recording of the current seismic activity, the Swiss Seismological Service (SED) is analyzing the data recorded thus far by the six stations built to monitor the geothermal energy project. Yesterday, our technicians also collected the data from four other stations. This data will also be incorporated into the investigations. The four temporary seismometers were installed on June 4, 2013, in order to observe the test and stimulation phase even more closely. While the six permanent stations send their recordings to Zurich in real time, the temporary seismometers record them locally.
There are currently over 400 reports from people who felt the earthquake last Saturday (Report an earthquake). Most of those affected felt a bang and a bump, with many mentioning two bumps in quick succession (approximately 1 second). Only a minority reported moving objects, flapping doors, or swinging lampshades. Compared with the quake triggered by the Deep Heat Mining Project in Basel (magnitude of 3.4) on December 8, 2006, the one in St. Gallen was felt by significantly fewer people, despite its slightly greater magnitude.
