Up and down wave separation of multicomponent data at the ocean bottom

Chanpen Silawongsawat, Gary F. Margrave

An elastic modelling program (Elmo) has been modified to generate multicomponent synthetic seismic data at the ocean bottom. The program is also able to fully separate P and S into their up or down subset. A proposed scalar-combination method to separate up and down coming waves at the ocean bottom is then tested with this synthetic data. The scalar relationship between the vector wavefield of particle velocity and the scalar wavefield of pressure based on Hooke's law is reviewed. With total measurement of downcoming wave accounted for, the expressions to combine the ocean bottom multicomponent data for the upcoming waves in each component are restated. Some synthetic results for different definitions of up and down wave separation are produced. The results of the scalar combination method for each component are shown to have successfully separated up and downcoming waves.