Earthquake in southern Sweden wakes up Denmark on 16 December 2008

Abstract

A moderately strong earthquake struck southern Sweden 5 km south-west of the town of Sjöbo, 60 km east of Malmö, in the early morning at 6:20 a.m. local time on 16 December 2008. The epicentre was located in Skåne, a region that is known for its extremely low seismicity, and its location was determined to be 55.5°N and 13.6°E with an uncertainty of about 6 km. A depth of 9 km with an uncertainty of 3 km was obtained from teleseismic observations at the Yellowknife seismic array, USA. Since waveform data from the Swedish national seismic network are not yet available, depth estimation using local stations has so far not been attempted. During the period 1970–2008, only three small earthquakes were detected in the region; the largest measured 2.8 on the local Richter scale. To our knowledge none of these previous earthquakes were felt by people. The historical archives dating back to 1375 show that 14 other earthquakes have been felt in the area. The largest of these, recorded in 1894, was felt over an area of 7300 km² and had an epicentre 50 km east of the 16 December 2008 earthquake (Scandinavian Earthquake Archive 2003). The activity in southern Sweden is similar to that of northern Sjælland and north-western Jylland, and confirms the low seismicity of the region (Gregersen et al. 1991).