U.S. Geological Survey       National Strong-Motion Program

Event Name: Southeast Anchorage, Alaska Earthquake (1st mainshock)
Event Date: 02/06/2002, 17:18:46 UTC (08:18:46 AM AKST)
Event Identification: 20020206_1
Recorder Type: Etna, K2


Data Organization and Format ||  Downloads (updated 03/12/2002) ||  Tables (updated 03/12/2002


Data Organization and Format

The February 06, 2002 17:18:46, UTC Mb 4.9 (NEIC), ML 5.0 (AEIC) Southeast Anchorage, Alaska Earthquake data recorded by the USGS National Strong-Motion Network (NSMN) are available via the NSMP ftp server in the folder (directory) "20020206_1" (https://ca.water.usgs.gov/nsmp/20020206_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 "20020206_1/" on the NSMP ftp server, "https://ca.water.usgs.gov/nsmp/20020206_1".   New time series and peak values data for six additional stations added on 02/28/2002. Hypocenter and magnitude parameters for data posted on 02/06/2002 were revised on 02/28/2002 (time series and peak values were not affected).  Time series and peak values data for station 8016 (Anchorage; BP Building, S/N 1356) were added to the data set on 03/08/2002 and were revised on 03/12/2002 to correct for an error in sensitivity that caused amplitudes to be higher by a factor of two.

20020206 Southeast Anchorage Earthquake (1st mainshock) Downloads in ".zip" format

20020206_1_uncorr.zip     uncorrected  (1.0 Mb; uncompresses to 3.4 Mb; updated 03/12/2002)
20020206_1_corr.zip     corrected (4.9 Mb; uncompresses to 14.4 Mb; updated 03/12/2002)

Tables

List of corrected peak ground accelerations and velocities for available time-series data (to obtain list as Excel spreadsheet click here ; click cancel button if get pop-up window requesting user name and password) updated 03/12/2002


Return to top of page.
Return to Data Sets page
Return to NSMP Homepage

This page was posted on February 06, 2002; updated 03/12/2002.