Earthquakes in Switzerland and surrounding regions during 2009

This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2009. During this period, 450 earthquakes and 68 quarry blasts were detected and located in the region under consideration. The three strongest events occurred about 15 km NW of Basel in southern Germany (M L 4.2), near Wildhaus in the Toggenburg (M L 4.0) and near Bivio in Graubünden (M L 3.5). Although felt by the population, they were not reported to have caused any damage. With a total of 24 events with M L ≥ 2.5, the seismic activity in the year 2009 was close to the average over the previous 34 years.