Baltic shield seismicity, The results of a regional network

The seismicity of the southern part of the Baltic shield has been studied for four years by a digital regional seismic network with a station spacing of 100km. Some 160 earthquakes have been analysed for location, focal depth, seismic moment, fault plane solution and static stress drop. More than 90% of the earthquakes occur at depths less than 19km. Orientation of the horizontal stresses relaxed by the events is very consistent, the principal compression is oriented in a NW-SE direction. The geographical distributions of the events show relations to the regional geology. The consistency of the stress pattern means that the type of faulting is mainly determined by the strikes of the available faults.