Overview of results from active source seismic reflection and refraction surveys acquired in the Swedish Caledonides and vicinity

The first larger scale seismic refraction survey over the Swedish Caledonides appears to date back to 1969 as part of the Trans-Scandinavian Deep Seismic Sounding project (Vogel and Lund, 1970). Forty-two receiver locations were occupied between Sundsvall and Trondheim with shot points off the coast of western Finland and in the water near Trondheim. Interpretation of P-wave arrivals and modeling showed a crust that is generally 40-45 km thick below the Baltic Shield, but that thickens some kilometers below the mountain belt, a result consistent with more modern interpretations (c.f. England and Ebbing (2012)). Since then a significant number of additional refraction surveys have been performed over the Swedish Caledonides, as well as larger scale reflection seismic surveying. The Collisional Orogeny in the Scandinavian Caledonides (COSC) reflection profile played a significant role in the siting of the two ICDP boreholes, COSC-1 (2.5 km deep) and COSC-2 (2.275 km deep) that were drilled in the mountain build in 2014 and 2020, respectively. Results from earlier active source seismic experiments will be reviewed in this presentation, as wells as more recent results from the COSC project.

 

Vogel A. and Lund C.-E., 1970. Combined Interpretation of the Trans-Scandinavian Seismic Profile, section 2-3. Internal Report No. 4, Dept. of Solid Earth Physics, Uppsala University, 25pp.

England R.W. and Ebbing J. 2012. Crustal structure of central Norway and Sweden from integrated modelling of teleseismic receiver functions and the gravity anomaly. Geophys. J. Int., 191, 1–11.