The investigation of the ice field influence on the seismic prospecting works in the Arctic region

Abstract

Different ice constructions, such as ice fields, ice ridges, icebergs, are of great interest for the research, for example, in the seismic prospecting works. Ice constructions, especially ice fields, bring in lots of extra reflections into the seismograms, which are very difficult to differ from the reflections, coming from the hydrocarbon deposits, which are of great importance for the geologists. For the decrease of the influence of the reflections from the ice field, the seismic source of impulse is often established deep into the ice cover, approaching the contact border between the ice and the water layer. In this work, the results of mathematical modelling of the seismic waves spread through the geological layers of the Arctic region with the help of the grid-characteristic method are presented. The analysis of influence of establishing the source of impulse on the border between ice and water on the decrease of the seismic wave velocities, on the wave fields is carried out. The model with the seismic source of impulse, located on the contact border between ice and water, makes worse the final result, while the model with the source of impulse on the surface of ice demonstrates a decrease of the seismic wave velocities.