Glacially induced seismicity in Europe

Glacial cycles of the last Ice Age have affected the Earth in various ways. The best known effects are the deformation of the Earth’s surface, changes in the geopotential and the Earth’s rotation. Less attention is given to the associated effect of stress changes which has led to the reactivation of faults near the end of the last glaciation, ~10,000 years ago, in northern Scandinavia, the British Isles, Germany and North America. These faults are termed glacially induced faults (GIFs). Although GIFs in Scandinavia have been studied for a long time, it was believed that they must be located within the formerly glaciated area. However, there is growing evidence that melting of large ice sheets has been able to trigger fault reactivation and earthquakes just outside the migrating ice limit.

We will briefly review the seismicity and GIFs in Scandinavia, but then set the focus on recently discovered GIFs in northern central Europe and the historic earthquakes of the area. With the help of three-dimensional numerical models we show the link of deglaciation to these faults and present the first consistent explanation for the occurrence of deglaciation seismicity and the historic earthquakes in northern Central Europe.