ALBERT

Description: 〈span〉〈div〉SUMMARY〈/div〉A promising way to perform seismological studies in the Arctic region is deploying seismic stations on ice floes. The pioneering works by the Alfred Wegener Institute Bremerhaven have demonstrated the efficiency of such floating networks to explore local and regional seismicity and to build 3-D seismic models. However, problems remain, related to the identification of different types of seismic waves, particularly 〈span〉S〈/span〉 waves. Here, we perform 2-D and 3-D numerical simulations of seismic waves emitted by an earthquake to explore the possibility of recording different phases on the sea surface. We use different types of simple shear source models, namely strike-slip, vertical displacement and normal faults. In the calculated wave field, we obtain three major types of seismic waves recorded on the sea surface—〈span〉Pw, Sw〈/span〉 and 〈span〉SPw〈/span〉 (〈span〉w〈/span〉 denotes an acoustic wave in the water layer)—and numerous multiple waves. The clarity of the recorded phases strongly depends on the type of wave, source mechanism, epicentral distance, thickness of the water layer and depth of the source. For example, the 〈span〉Pw〈/span〉 phase is clearest for the strike-slip mechanism, less clear for the normal fault and almost invisible for the vertical displacement. The 〈span〉Sw〈/span〉 phase is observable in all of these cases; however, it can be confused with the 〈span〉SPw〈/span〉 phase that arrives earlier. In addition, at some distances, the 〈span〉Sw〈/span〉 wave interferes with the multiple 〈span〉Pw2〈/span〉 wave and therefore is hardly detectable. In summary, the numerical simulations in a model with a water layer have demonstrated several non-obvious features of wave propagation that should be taken into account when analysing experimental data recorded on ice floes.〈/span〉