The Storfjorden, Svalbard, 2008-2012 aftershock sequence: Seismotectonics in a polar environment

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• 作者：Myrto Pirli ; Johannes Schweitzer ; Berit Paulsen
• 关键词：BFZ ; Billefjorden Fault Zone ; CLVD ; compensated linear vector dipole ; COB ; continent&ndash ; ocean boundary ; HFZ ; Hornsund Fault Zone ; IPY ; International Polar Year ; ISC ; International Seismological Centre ; LAFZ ; Lomfjorden&ndash ; Agardhbukta Fault Zone ; MT
• 刊名：Tectonophysics
• 出版年：2013
• 出版时间：2 August, 2013
• 年：2013
• 卷：601
• 期：Complete
• 页码：192-205
• 全文大小：1616 K

文摘

A long, complex aftershock sequence has followed an M_w 6.1 mainshock in February 2008, in Storfjorden, Svalbard. Relatively located aftershock epicenters and focal mechanisms from moment tensor inversion suggest that the series took place along a NE-SW trending and steeply SSE dipping oblique-normal fault, with the total aftershock extent exceeding the mainshock rupture. The magnitude of the mainshock and the duration of the aftershock activity render the Storfjorden sequence important in terms of earthquake hazard assessment in the Svalbard region. We have evaluated all involved uncertainties and combined seismological information with background knowledge for the area, in order to achieve as sound a seismotectonic interpretation as possible. Our results clearly indicate that the activity in Storfjorden should be attributed to a previously unknown tectonic structure. In addition, there are indications of activation of secondary structures and possibly of stress triggering. These new findings affect our understanding of the region's earthquake potential.