LOCATION OF CRUSTAL FRACTURED ZONES USING A FORMAL ALGORITHM ON GRAVITY AND TOPOGRAPHIC DATAV. A. Zheligovsky, O. M. Podvigina, and A. M. Sadovsky
We studied crustal fracturing in California from topography and Bouguer gravity anomalies using a formal algorithm for identifying linear features from the values of geophysical fields on a regular grid. Some of the linear features thus identified coincide with known faults. They may be interpreted as boundaries of geologic units which are deep-seated when based on Bouguer anomalies and shallow when using altitude data. Areas are predicted where horizontal faults may be situated. Low ($M\ge 3$) and high ($M>6$) seismicity are shown to be associated with areas where the crust has been found to be fractured.