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NORSAR has been involved in a considerable number of investigations that have focused on the recent and present crustal deformation history. The cooperation project NEONOR was the most prominent one focusing on neotectonics in Norway. A number of surface deformations could be related to the deglaciation period, and some (like the Stuoragurra fault in Finnmark) was found active even today. Through the calculation and analysis of earthquake focalmechanisms the mode of deformation as well as direction of compressive and tensile stresses can be determined. This was done for local regions as well as for all of Fennoscandia, and it was possible to support a regional model for deformation causes for crustal deformation that presently generate also the earthquakes.
FIG 1 Earthquakes in Fennoscandia during different periods of observation. From Fjeldskaar et al. 2000.
FIG 2 Stress directions, type of faulting and focal depths synthesized from earthquake focal mechanisms and in situ stress measurements. Areas of less data are indicated with questionmarks. Intensity of yellow indicates intensity of seismicity. From Fjeldskaar et al., 2000.
References
Fjeldskaar, W., C. Lindholm, J.F. Dehls and I. Fjeldskaar (2000): Postglacial uplift, neotectonics and seismicity in Fennoscandia. Quaternary Science Reviews 19 (2000) 1413 - 1422
Hicks E., H. Bungum, C. D. Lindholm (2000): Seismic activity, inferred crustal stresses and seismotectonics in the Rana region, Northern Norway. Quaternary Science Reviews 19 (2000) 1423 - 1436
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