Structural model of the pre-Tertiary basement in the Kr ko basin

Based on seismic reflection profiles recorded in the last ten years in the frame of the investigations for assessment of earthquake hazard at the location of the Kr ko nuclear power plant, and taking into account relevant geological and gravimetric data as well asresults of deep boreholes, two structural model of the pre-Tertiary basement in the Eastern part of the Kr{ko basin were constructed. In the first model the depth contours of the pre- Tertiary basement were drawn by hand, and in the second model the radial based functioninterpolation method was applied. In the Eastern part of the Kr{ko basin two depressions were distinguished. The Western one – Raka depression is smaller and shallower (max. depth of 1600 m), meanwhile the Eastern one – Globoko depression is larger and deeper(max. depth of 2050 m). In-between is a saddle at Drnovo where the pre-Tertiary basement lies at the depth of approx. 1000 m. Three-dimensional model will be used in further studies as is seismological modelling of the influence of the shape of the sedimentary basinon the seismic ground motion in case of an earthquake.