SVEKALAPKO wide-angle refraction and reflection survey

The SVEKALAPKO project was a multidisciplinary geoscientific research project aiming to investigate the evolution of the crust and lower lithosphere of the Fennoscandian shield. The project included a seismic experiment conducted with an array covering the southern half of Finland consisting of 40 broad-band and 88 short-period temporary stations as well as 15 permanent stations. The station spacings were on average 100 km for broad-band and 50 km for short-period stations. The array was operating continuously from August 1998 to May 1999. The final event list included 1356 selected events recorded by the array. The events included teleseismic, regional and local events. Four two-dimensional crustal P-wave velocity models were originally constructed from local event data recorded along profile swathes by Yliniemi et al. (2004). As the profile swathes are very wide, the position of the velocity models is not exact, being between shot points at the ends of the profile. The three available models were obtained by Yliniemi et al. (2004) using a trial-and-error ray tracing method. In addition to a general velocity structure, the models show reflective structures in the upper mantle. Velocity model of profile 1 in Yliniemi et al. (2004) is not included in the available data as the original model has been lost. Wide-angle sections are not available for the SVEKALAPKO data. Yliniemi, J., E. Kozlovskaya, S.-E. Hjelt, K. Komminaho, and A. Ushakov, 2004. Structure of the crust and uppermost mantle beneath southern Finland revealed by analysis of local events registered by the SVEKALAPKO seismic array. Tectonophysics 394: 41–67.