ZEMĚTŘESENÍ V HOSTĚRADICÍCH V ČERVNU 2014

Abstract

Southern Moravia – a southeastern part of the Czech Republic at the contact of the Bohemian Massif and the Carpathian Foredeep – is one of the regions with the lowest seismic activity in the Czech Republic. Reports on historical earthquakes in this area are sporadic and poorly evidenced, many of the messages are in fact observations of earthquakes originating mainly in Austria. Instrumental seismic monitoring in southern Moravia commenced in 1995. Thereafter only three local earthquakes were observed – magnitude 2.5 event near Hostěradice in 2000, perhaps induced event near Uhřice in 2003 with magnitude of 0.7 and magnitude 1.4 earthquake near Božice in 2006.A sequence of four weak earthquakes in June 2014 is only the fourth occurrence of earthquakes in southern Moravia since the beginning of instrumental measurements. Events originated near Hostěradice (SE margin of the Bohemian Massif), 40 km southwest of Brno. The strongest event reaching local magnitude of 2.0 occurred on June 1, 2014 at 00:43 UTC. It was felt by people close to the epicentre with a macroseismic intensity 4 European Macroseismic Scale EMS-98. A temporary seismic station was immediately installed in the epicentral area. The station recorded two of four shocks and helped to confi rm a focus position of the sequence: 48.95° N 16.24° E, depth 3 km.In 2014 a review of historical earthquakes in this region was conducted using new catalogues of historical earthquakes in neighboring countries in order to avoid confusion between local and regional phenomena. Some new information sources were found. In any case, historical earthquakes in this region are very rare and most of them are poorly substantiated.