A computerized earthquake catalog system that integrates basic information on all earthquakes reported in California has been developed by that state's Division of Mines and Geology. The system provides for file generation and maintenance and for data retrieval. Earthquake records can be selected according to magnitude, date of occurrence, geographical coordinates, and other parameters.

Seismologists Charles R. Real and Tousson R. Toppozada explain that earthquake recurrence studies can be made within any desired area. The size of search area can be computed, and the recurrence coefficients can be determined by least squares and maximum likelihood techniques.