EARTHQUAKES IN CALIFORNIA (1769-1927)

          SEISMICITY  LIST  PREPARED FOR THE NATIONAL OCEANIC AND
          ATMOSPHERIC ADMINISTRATION BY DONALD A. SEEBURGER UNDER
          THE SUPERVISION OF BRUCE A. BOLT, DIRECTOR OF THE SEIS-
          MOGRAPHIC STATIONS, UNIVERSITY OF CALIFORNIA, BERKELEY.
          PROGRAMMING AID BY ROBERT UHRHAMMER. STUDY COMPLETED IN
                                JUNE, 1976.


                                - SOURCES -

B. A. Bolt and R. D. Miller, "Catalogue of Earthquakes in Northern California
     and Adjoining Areas, 1 January 1910 - 31 December 1972", Seismographic
     Stations, University of California at Berkeley,1975.
 
"Earthquake History of the United States", Revised 1970, U. S. Department
     of Commerce, U. S. Printing Office, 1973.

B. Gutenberg and C. F. Richter, "Seismicity of the Earth", 1954, Princeton
     University Press.

E. S. Holden, "Catalogue of Earthquakes on the Pacific Coast, 1769-1897",
     Reprinted from the Smithsonian Miscellaneous Collections, No. 1087.

S. D. Townley and M. W. Allen, "Descriptive Catalog of Earthquakes of the
     Pacific Coast of the United States, 1869 to 1928", B.S.S.A., V. 29,
     No. 1, Jan 1939.

H. O. Wood and N. H. Heck, "Earthquake History of the United States, Part 22",
     U.S.C. and G.S. Serial No. 609, Revised 1951.
 
 

                                 - INTRODUCTION -

     This list is essentially an edited abstract of the Townley-Allen
Catalog of California Earthquakes, 1769-1927. The Townley-Allen Catalog has
been revised where necessary after making seismological inferences based on
the modern understanding of earthquakes, tectonic structure, published field
observations and damage reports available, and after making assessments of
the historical accuracy of the catalog entries by means of intercomparison
and internal con- sistency checks. Account was also taken of some recent
special studies of individual earthquakes.

     The list entries give the Date, Time (GMT), Location, and a summary of
the more significant observations associated with the earthquake. Included
in the description is an estimate of the maximum Modified Mercalli Intensity
exper- ienced during the earthquake. The Townley-Allen Catalog uses the
Rossi-Forel Intensity Scale. A listing of the Modified Mercalli Scale and an
approximate conversion scheme from Rossi-Forel to Modified Mercalli are to
be found in Richter, "Elementary Seismology", pp. 135-39, 650-52. Modified
Mercalli Intensities were assigned based upon the following criteria:

     1) If a description of earthquake effects exists, a Modified Mercalli
        Intensity was assigned after considering both the given Rossi-Forel
        Intensity and the description.

     2) If no description was available, the conversion was made based upon
        relations such as those presented in Richter, referred to above. If
        the conversion relations give an inter mediate value, then, lacking
        further evidence, the given Modified Mercalli Intensity is the lower
        of the two values.

     All magnitudes listed are taken from Gutenberg and Richter, "Seismicity
of the Earth".


                                     - NOTES -

     1)  Time listed is Greenwich Mean Time.

     2)  Earthquake locations are placed at the inferred center of the zone
         of highest intensity.

     3)  Entry Reference:

         F - The Townley-Allen entry is geographical, the list entry gives
             the Time and Location.

         G - The Townley-Allen entry gives a description of the earthquake
             effects, the list entry is an abstract of the Townley-Allen
             account.

         H - The list entry is a major revision of the Townley-Allen account,
             the source of the revision is noted.