• Data Release Summary
• Station map
• List of processed data, recorded peak acceleration, and links to data files and plots of processed data
• Typical record (USC No. 34)
• Archive of the First Hector Mine Earthquake Data report, of 17 October, 1999
• Acknowledgments
• Acknowledgment of Data Source
• Related Web Sites

The Hector Mine earthquake of  16 October, 1999, 2:46 am PDT (M=7.1, epicenter at 34.6 N and 116.27 W, depth=6 km; USGS/Caltech) occurred about 200 km northwest of Los Angeles (approximately 47 miles east southeast of Barstow and 32 miles north of Joshua Tree).  The Los Angeles and Vicinity Strong Motion Network had 78 stations in the field at the time of this earthquake, all equipped with SMA-1 accelerographs.  All the stations were operational.  Only 39 stations triggered because the motion throughout Los Angeles basin were small.  The USC team visited all the 78 stations between 16 October and 1 November.  The records were digitized, processed and posted on this web page within few days after they were recovered.  All the records were processed and posed by 2 November, 1999.

Table 1 summarizes the uncorrected peak accelerations. Fully processed data, i.e. uncorrected acceleration (Volume 1 data), corrected velocity and displacement (Volume 2 data), and Fourier and Response spectra (Volume 3 data) can be downloaded via anonymous FTP by clicking on the hot links in Table 1.  Plots of Volume 2 and 3 data, in PDF format, can also be downloaded.   The data was processed by the Lee and Trifunac's LeAuto and LeBatch software packages (references can be found on the USC Strong Motion Data Processing Laboratory web page).   Figure 1 shows the location of the stations.

The Los Angeles and Vicinity Strong Motion Network currently consists of 78 stations, and has been operating since 1979/1980.   The purpose of this network has been to record strong ground shaking in metropolitan Los Angeles, that would help improve the understanding of the variation of ground motion in relation to the local and regional geology, and to provide the engineering community with information on strong motion  in relation to its effects on the built environment.

The ground motions from this earthquake in Los Angeles were small, and were not likely to have caused significant damage.  Nevertheless, the recorded motions will be useful because of the deficiency of the available strong motion data (in the Western US) in records of large and distant earthquakes. (This deficiency is due to the fact small amplitude records are often given low priority to process).   In that respect, the motions recorded by the Los Angeles and Vicinity Strong Motion Network will contribute valuable data for statistical regressions of strong motion data and development of empirical scaling models.

Quickly viewable  GIF plots of  Volume 2 data at selected stations: USC  06 USC  34 USC  58 USC  65 USC  68 USC  70 USC  73 USC  77 USC  93 USC  95

A Typical Record: Station USC No. 34

Click here to view this report

The network operation and the processing of the Hector Mine records has been supported by NSF grant CMS 9812721.

End Users of these data are kindly requested to acknowledge in publications the USC Strong Motion Group as source of these data. Some data files in this release may be modified in the future.

To insure that the integrity of the data is maintained, and that the end users get the most recent version, Secondary Data Distributors should first contact the USC Strong Motion Group. Secondary Data Distributors should also advice end users to acknowledge the USC Strong Motion Group as the Data Sources.

Information Services Providers are advised that appropriate reference to this data release is the URL address of this web document

• Strong Motion Research Group Home Page
• Strong Motion Data Processing Laboratory
• Los Angeles and Vicinity Strong Motion Network
• M_L=6.4 Northridge Earthquake and Five M>5 Aftershocks

Site update history:
Created:  10/17, 1999
Last updated: 11/08, 1999

Send comments to: mtodorov@usc.edu