U.S. Geological Survey       National Strong-Motion Program

Event Name: Anza, California Earthquake
Event Date: 10/31/2001, 07:56 UTC (10/30/2001, 11:56 PM PST)
Event Identification: 20011031_1
Recorder Type: Etna, K2


Data Organization and Format ||  Download (updated 11/29/2001) ||  Tables (updated 11/29/2001)


Data Organization and Format

The October 31, 2001, 07:56 UTC ML 5.1 Anza, California Earthquake data recorded by the USGS National Strong-Motion Network (NSMN) are available via the NSMP ftp server in the folder (directory) "20011031_1" (https://ca.water.usgs.gov/nsmp/20011031_1).    The time series provided are available in uncorrected acceleration, corrected acceleration, corrected velocity, corrected displacement, response spectra (relative displacement, relative velocity, pseudo-velocity, and absolute acceleration), and Fourier amplitude spectra of corrected acceleration.  All of the data are in SMC format.

In a departure from previous file-naming conventions (where for a particular channel the different the time series data all had the same filename, and thus required separate directories for each data type), the file names for the data have the following form:

uncorrected acceleration: RRRRc_u.smc
corrected acceleration: RRRRc_a.smc
corrected velocity: RRRRc_v.smc
corrected displacement RRRRc_d.smc
response spectra: RRRRc_r.rs2
Fourier amplitude spectra (f): RRRRc_f.fs1

where 'RRRR' is the four-digit recorder serial number (including leading 0's), 'c' is the channel number of the recorder ('a' corresponds to channel 1, 'b' to channel 2 , etc), the '_x' is used to identify the data type, and the suffix refers to the data format (rs2 and fs1 are valid SMC format types recognized by the BAP processing program.

The data are stored in two directories: uncorrected (only uncorrected acceleration) and corrected (all of the corrected and processed data, including acceleration, velocity, displacement, response spectra and Fourier amplitude spectra. This convention for organizing the data was implemented to avoid confusion between the directory names (Vol1, Vol2, … Vol6) previously used for some earlier events and the standard conventions for Volume1, Volume2 and Volume 3 processing.

Information on how the data are processed can be found in the section on DATA PROCESSING.


Downloads

To facilitate downloading the data, the data have been compressed into PC compatible ".zip" format.  The same zip file is located in the "zips" folder in "20011031_1/" on the NSMP ftp server, "https://ca.water.usgs.gov/nsmp/20011031_1".  Time series data for stations 5069 (Fun Valley Reservoir, S/N 0525),  5073 (Cabazon, S/N 0587), 5222 (Tripp Flats Training Camp, S/N 0594), 5072 (Whitewater Trout Farm, S/N 1405), and 5220 (Borrego Springs Clinic, S/N 2046) were added to the data set on 11/05/2001.  Horizontal sensor orientations for station 5331 (San Bernardino; Del Rosa Work Station, S/N 2008) were corrected on 11/14/2001.  Time series data for station 817 (Hinds Pumping Plant, S/N 1924) were added to the data set on 11/29/2001.

20011031 Anza Earthquake Downloads in ".zip" format

20011031_1_uncorr.zip     uncorrected  (3.1 Mb; uncompresses to 10.1 Mb; updated 11/29/2001)
20011031_1_corr.zip     corrected (15.7 Mb; uncompresses to 45.5 Mb); updated 11/29/2001)

Tables

List of corrected peak ground accelerations and velocities for available time-series data (to obtain list as Excel spreadsheet click here ) (updated 11/29/2001)


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This page was posted on November 02, 2001 (updated 11/29/2001).