P wave seismic velocity structure derived from sonic logs and industry reflection data in the Los Angeles basin, California

Abstract

We present a new three‐dimensional seismic P wave velocity model of the Los Angeles basin that is based on more than 150 sonic logs and 7000 stacking velocities from industry reflection profiles. The model was developed using kriging techniques implemented in GoCAD (a commercial application specializing in the construction of surfaces, the analysis of spatially distributed data, and the modeling or simulation of properties) and is characterized by a heterogeneous, spatial varying velocity gradient with maximum velocities of ∼5000 m/s in the sedimentary section. Variability of the observed P wave velocities increases with depth, reflecting complex structural and sedimentological controls. The model contains a new representation of the basin shape as defined by the sediment‐basement interface, which was mapped using well control and seismic reflection profiles. Our model differs substantially in approach and outcome from previous representations of crustal velocity structure in southern California.