Three Recent Larger Earthquakes Offshore Norway.

摘要

Three earthquakes of magnitude around 5 occurred offshore western Norway on 5 February 1986, on 8 August 1988 and on 23 January 1989. These earthquakes, representing the highest seismic activity in this area for at least 30 years, were all felt by people over most of southern and central Norway. Focal mechanism solutions for these earthquakes indicate thrust faulting along N-S to NNE-SSW striking fault planes, in response to NW-SE compressional stress, most probably of plate tectonic origin. A number of high quality digital recordings of the ground motions at various distances from these and other recent earthquakes in Norway have shown that source spectral as well as wave attenuation characteristics in this area are reasonably consistent with what has been derived from other intraplate areas. Keywords: Source mechanisms, Regional attenuation, Synthetic seismograms. (sdw)