William H. Bakun

U. S. Geological Survey

345 Middlefield Rd. MS977

Menlo Park, California 94025

Open-File Report 98-584

This report is preliminary and has not been reviewed for conformity with U. S. Geological Survey editorial standards or with the North American stratigraphic code. Any use of trade, product or firm names is for descriptive purposes only and does not imply endorsement by the U. S. Government.

1998

Modified Mercalli Intensity (MMI) data for recent California earthquakes were used by Bakun and Wentworth (1997) to develop a strategy for bounding the location and moment magnitude M of earthquakes from MMI observations only. Bakun (Bull. Seismol. Soc. Amer., submitted) used the Bakun and Wentworth (1997) strategy to analyze 19^th century and early 20^th century San Francisco Bay Region earthquakes. The MMI data and site corrections used in these studies are listed in this Open-file Report. This report is also accessible at http://quake.wr.usgs.gov/~bakun/.

Table 1. Modified Mercalli Intensity Observations for Bakun

and Wentworth's (1997) Training-set Events…… Pages 1 to 93

Table 1 Part 1/4: 28 June 1966 through 28 April 1979

Table 1 Part 2/4: 8 May 1979 through 2 May 1983

Table 1 Part 3/4: 9 May 1983 through 26 September 1984

Table 1 Part 4/4: 31 March 1986 through 17 January 1994

Table 2. Site Corrections and Geologic Descriptions of

Bakun and Wentworth (1997)…… Pages 94 to 132

Table 3. Modified Mercalli Intensity Observations for Bakun

and Wentworth's (1997) Test-set Events…… Pages 133 to 153

Table 4. Modified Mercalli Intensity Observations for San

Francisco Bay Region earthquakes (1836 to 1927)…… Pages 154 to 175

The MMI for Bakun and Wentworth's (1997) training-set and test-set events are listed in Tables 1 and 3 respectively. The MMI are listed in chronological order, then by decreasing MMI, and finally by community name in alphabetical order. The site corrections, and the California geology and soil classes as defined in Bakun and Wentworth (1997), are listed in Table 2. The MMI data used by Bakun (submitted), organized as described above for Tables 1 and 3, are listed in Table 4.

Bakun, W. H. and C. M. Wentworth (1997). Estimating earthquake location and

magnitude from seismic intensity data, Bull. Seismol. Soc. Amer. 87, 1502-1521.

Bakun, W. H. (1999). Seismic Activity of the San Francisco Bay region, Bull. Seismol.

Soc. Amer., submitted.