Most earthquakes occur along plate boundaries and arise from of frictional strain between lithospheric plates. The energy released during rupture is transmitted through earth as seismic waves.
The study of waves having different properties provide important information the earth¿s interior. The worldwide distribution of earthquakes can be explained in the context of plate tectonics, and this model also permits a general, long-term forecast of hazard related to future earthquakes. However, is not possible to predict when and where earthquakes will occur.
Shallow earthquakes may result in faulting at the surface, and may cause great damage if the movement is large. Severe damage may also result from energy released at depth in the earth being transmitted to the surface by seismic waves. Large submarine earthquakes may cause tsunamis that have devastating effects in coastal areas very far from the site of the earthquake.
Small earthquakes may occur far from plate boundaries. Although the activity in Norway is moderate, a few earthquakes are noted by humans each year. Only a limited number of historical earthquakes have caused damage to buildings and infrastructure.
The seismic activity in Norway and adjoining areas is monitored by NORSAR and the University of Bergen.