Abstract
Between June 2004 and September 2004 a temporary seismic network was installed on the northern insular shelf of Iceland and onshore in north Iceland. The seismic setup aimed at resolving the subsurface structure and, thus, the geodynamical transition from Icelandic crust to typical oceanic crust along Kolbeinsey Ridge. The experiment recorded about 1,000 earthquakes. The region encloses the Tjörnes Fracture Zone containing the Husavik–Flatey strike-slip fault and the extensional seismic Grimsey Lineament. Most of the seismicity occurs in swarms offshore. Preliminary results reveal typical mid-ocean crust north of Grimsey and a heterogeneous structure with major velocity anomalies along the seismic lineaments and north–south trending subsurface features. Complementary bathymetric mapping highlight numerous extrusion features along the Grimsey Lineament and Kolbeinsey Ridge. The seismic dataset promises to deliver new insights into the tectonic framework for earthquakes in an extensional transform zone along the global mid-ocean ridge system.
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Acknowledgments
We thank Captains Ragnar G. D. Hermansson, and Gudmundur Bjarnasson and their crews for excellent support during the marine surveys. We ackowledge financial support by the Deutsche Forschungsgemeinschaft (DFG) under grants Da 478/13-1 and Ri 1220/2-1, the Swedish Vetenskapsradet, the Icelandic Research organization and the Leitstelle für mittelgrosse Forschungsschiffe for taking over the costs for the scientific cruises. Further more we are grateful for the access to instruments of the Geophysical Instrument Pool Potsdam, and for the shot permission and for the research permission to the Icelandic Research organization (RANNIS). C. Riedel also wants to thank Reinhard Wineberger at the german embassy in Reykjavik for unbureaucratic and fast support.
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Riedel, C., Tryggvason, A., Brandsdottír, B. et al. First results from the North Iceland experiment. Mar Geophys Res 27, 267–281 (2006). https://doi.org/10.1007/s11001-006-9007-0
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DOI: https://doi.org/10.1007/s11001-006-9007-0