Modeling ocean-bottom seismic rotation rates

Modeling ocean-bottom seismic rotation rates

Ohad Barak and Shuki Ronen

Abstract:

Seismic systems today record up to four components which provide the particle displacement and the pressure. The pressure is proportional to the divergence of the displacement. We need the hydrophones because the divergence is useful and cannot be calculated in processing. The curl cannot be calculated from four component data just like the divergence cannot be directly calculated from the displacements. If the curl is useful, we can add rotation sensors to today's four component recorders and have seven component data.

To evaluate the added information that would come from rotation sensors we used elastic modeling. In our synthetic data experiment, we predicted the effect of a seabed scatterer on fully multi-component data. We used a pressure source that generates P waves. The P-waves are converted to S-waves and to surface waves propagating on the seabed. Our evaluation is that the added information from rotation sensors will be useful for identifying and separating surface waves from body waves.

Modeling ocean-bottom seismic rotation rates