![](lpsfig4a.gif)
![](lpsfig3b.gif)
Fig.4 (a) The plan and (b) the cross section of the two 3-D Los Angeles basin models: Model 1 and 2. The interfaces of Model 1 and 2 are constructed on the basis of the contours of the depth of 4000 and 6000 feet, respectively, on the Pre-Tertiary basement surface.