Experimental investigation of impact generated tsunami; related to a potential rock slide, Western Norway

Abstract Two-dimensional experiments of wave generation from the possible Akneset rock slide have been performed using solid block modules in a transect with a geometric scaling factor of 1:500. The width of the slide model was kept fixed at 0.45 m. The length of the blocks spanned from 1 to 2 m, the thickness was either 0.12 or 0.16 m and the front angle was 45°. Maximum water depth was 0.6 m with the slide plane having an angle of 35°. Three different scenarios were studied. Only the run out side was modelled. Surface elevations at three locations outside the sloping region were measured with ultra sonic wave gauges and discussed in light of hydrodynamic wave theory. Particle Image Velocimetry (PIV) was used to extract instantaneous velocity fields. Comparison is made between experimental velocity profiles and profiles consistent with a Boussinesq theory. High speed video of the impact was recorded and used to determine qualitative aspects of the forward collapse of the impact crater (backfill wave).