Surface wave analysis of Arabian Gulf ocean bottom seismic data | Conference Paper individual record

With an average water depth of 10-15 m and hard sea-bottom, strong surface waves create severe problems for seismic body wave imaging in the Arabian Gulf. Common techniques for surface wave analysis are frequency, f-k or velocity filtering techniques. However, spatial aliasing of surface waves due to under-sampling presents unique challenges to these methods. In this paper we explore the difference in time-frequency variations of different seismic events to analyze and attenuate Scholte waves and other P-related surface waves. In this study, we utilize the S transform instead of Fourier transform to build a t-f-k filter which provides a convenient way to analyze surface waves on separate f-k panels at different times. The velocity of Scholte waves ranges from 450 m/s to about 2100 m/s depending upon the spatial variation of seabed shear wave velocity. The P-related surface waves usually have a velocity ranging from 1300 m/s to 3500 m/s, which are more severely aliased than other waves in the seismic record. Analysis indicates that the proposed S-t-f-k transform is effective to attenuate these surface waves in this area and improve reflection signal quality, which may be applicable in other similar ultra shallow water environment.

author list (cited authors)
Zhang, Z., Sun, Y., & Berteussen, K. A.
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