Sea-bottom shear-wave velocities and mode conversions

Carlos Rodriguez-Suarez, Robert R. Stewart

Elastic parameters for shallow marine sediments are compiled using literature data (e.g., Hamilton, 1976;1979) and geotechnical data from offshore Brazil. The Brazilian data showed good agreement with Hamilton's results. Analyses of transmission and reflection coefficients for compressional- and shear-wave energy mode conversion using Zoeppritz equations were performed for both sea bottom and typical Tertiary sediment interfaces. We conclude, from previous published data and our results, that most S-wave reflection data recorded on the ocean floor are related to energy upcoming energy converted at an interface at depth and not from a downgoing shear conversion at the ocean floor.