Fennoscandian Earthquakes: Whole Crustal Rupturing Related to Postglacial Rebound

Local and regional earthquake locations provide seismic evidence that large shield earthquakes have occurred in northern Fennoscandia. These paleoearthquakes, with fault lengths of up to 160 kilometers and average displacements of up to 15 meters, were triggered by nonisostatic compressive stresses caused by the removal of the ice at the end of the last deglaciation. The Fennoscandian faults were probably formed by single events that ruptured through most of the crust. The largest event, moment magnitude M W ≈ 8.2, was larger than other known stable continent earthquakes outside failed rifts or extended crust.