California Historical Earthquake Online DatabaseClick on map for regional earthquakes
This website displays the felt effects for selected historical California earthquakes. By selecting a linked earthquake you can see a map of the area and intensity
of shaking from that earthquake. Then by clicking on a city on the intensity map (or list beneath the map) you can see what that location reported after
the earthquake. These “felt reports” are usually from newspapers during the 1850 to 1930 time period. The felt reports were compiled and published in 1981*
and 1982** with updates added through the years. Not all earthquakes have intensity maps and felt reports online since the conversion from printed report
to web page is an on-going process. Most of the San Francisco Bay area events between 1838 and 1906 are finished.
*Toppozada, T. R., C. R. Real, and D. L. Parke (1981). Preparation of isoseismal maps and summaries of reported effects for pre-1900 California earthquakes, Calif. Div. Mines Geol. Open-File Rept. 81-11 SAC, 182 pp.
**Toppozada, T. R. and D. L. Parke (1982). Areas damaged by California earthquakes, 1900-1949, Calif. Div. Mines Geol. Open-File Rept. 82-17, 65 pp.
To determine historical seismicity around a location:
Earthquake catalog from: Toppozada, T. R. and
D. Branum (2002) California M >= 5.5 earthquakes, history and areas damaged,
in Lee, W. H., Kanamori, H. and Jennings, P., International Handbook of
Earthquake and Engineering Seismology, International Association of Seismology
and Physics of the Earth's Interior.