Contact  |   Site Map  |   Search   
 Incorporated Research Institutions for Seismology  

  SeismoArchives  |   Earthquake Archives  |   Project Archives  |   Background Information  |         IRIS Home  


1957 Daly City Earthquake Archive:
In Memory of Manuel G. (“Doc”) Bonilla (1920-2007)

1957 March 22, 1957 at 19:44 UTC  37.67N  122.48W   Mw=5.3, Daly City, California

The Daly City earthquake of March 22, 1957 was the largest event on the northern San Francisco peninsula since 1906. Its magnitude is about 5.3, and damage to the dwellings was limited to mostly plaster cracking. It drew attention right away because it occurred about 20 km from the epicenter of the 1906 San Francisco earthquake. Several eminent geologists, earthquake engineers and seismologists investigated this earthquake, including Gorden B. Oakshott, M.G. Bonilla, Don Tocher, C.A. Whitten, Karl V. Steinbrugge, D.E. Hudson, and G.W. Housner (Calif. Div. Mines, Special Report 57, 1959; see also Marsden et al., 1995).

We welcome contributions of digital files of materials relating to the 1957 Daly City earthquake and financial donations to the endowment fund so that more seismograms can be scanned and made available online.  If you are interested, please contact W.H.K. Lee at <> (office) or  <> (home).

Archivist: Michael F. Diggles (
Endowment Donors: Porter Irwin, Willie Lee, Art McGarr, Mike Rymer, Carol & Carl Wentworth, and Kurt Servos (for providing funds to scan seismograms).
Contributor of Files: Michael Diggles.

1. Seismograms of the 1957 Daly City Earthquake:
   Please click the above link to view the selected seismograms of the 1957 Daly City earthquake (in preparation and not yet available).

link to compressed tif file directory (.gz format) (in preparation and not yet available).

2. Selected Information about the 1957 Daly City Earthquake now Online:
 Marsden, Richard: The Daly City Earthquake of 1957: What Does it Tell Us?
         from The Virtual Museum of the City of San Francisco
     Where can I Learn More About the 1957 Daly City Earthquake?
         U.C. Berkeley Seismological Laboratory

3. Reference:
Oakeshott, G.(ed.),The San Francisco Earthquakes of March 1957 , CDMG Special Report 57, 1959.

4. A Brief Note about M.G. “Doc” Bonilla

Doc Bonilla is a geologist noted for his field studies of active faults and their seismic hazards. He identified aspects of surface faulting and related earthquakes that are important in engineering applications and risk evaluation, then compiled, analyzed, and summarized the pertinent information in cooperation with others. He also published a paper on the geologic observations in the epicentral area of the 1957 earthquake (Bonilla, 1959). He was educated at the University of California , Berkeley (A.B., Geology, 1943), and Stanford University (M.S., Geology, 1960). He served as a research geologist of the U.S. Geological Survey from 1947 to 1993 and became a geologist emeritus in 1994.

Please click: Bonilla Photo for a photograph of Doc.

Please click: Biographical Sketch for M.G. Bonilla for a 1-page bio-summary written by Doc himself for the International Handbook of Earthquake and Engineering Seismology, edited by W.H.K. Lee, H. Kanamori, P.C. Jennings, and C. Kisslinger, Part B, p. 1878, Academic Press, San Diego, 2003.

Please click: Publications of M.G. Bonilla for a list of his publications, many of which are available online.


(Last Updated: February 21,  2006 ) (mfd)


Copyright © 2005 IRIS :: Contact