Southern California Earthquake Data Center


The SCEDC Archive

Historic Data Information (1932-1999)

The SCEDC has compiled and converted all available historic seismic data holdings into a single-source for online access to southern California earthquake data. This page describes the older parametric data that was loaded into the SCEDC Oracle database and the waveform data that was converted into the modern archival format.
These data are available for download via STP. Further description of the legacy catalogs can found in the "Downloads" section and in Hutton, Woessner, and Hauksson, 2010, BSSA.


  • The 1932-1976 era of seismic data was hand-typed from the original phase cards into electronic CUSP (Caltech-USGS Seismic Processing) format from the original hand-derived phase card solutions. The data was then imported into the SCEDC Oracle database, so phase and epicenter data is available for direct retrieval by users.
  • A problematic year span of CEDAR data, 1980, has been converted and processed to include magnitude information. The waveform data was read from tape and loaded onto the CUSP VAX system and converted to mSEED format.
  • The parametric data from 1981 to present has been loaded into the Oracle database system and the waveforms for that time period have been converted to mSEED format and are accessible through the STP interface. Quality control verification of 1981-2000 historic parametric and waveform data has progressed using a detailed reverse-chronological examination and verification of magnitudes.


Data Sources

Year phase epicenter waveform on/offline Source / Comments
1932-1976 Y Y - online phase cards / ASCII catalog / keypunched data from phase cards
1977-1979 Y Y - online CEDAR System / ASCII catalog / Corbett tapes / "PINK" cards
January 1980 - early 1981 Y Y Y online CEDAR System / short-lived UNIX System / ASCII catalog / Corbett tapes / "PINK" cards missing waveforms for 2/13-2/21/1981, missing waveforms for March 1981; missing events for 3/15-3/31/198; no timed data for 1/1-2/13/1981
April 1981 - February 1983 Y Y Y online CUSP
March 1983 - June 1983 Y Y Y online CUSP / untimed data in March-June 1983
July 1983 - 1999 Y Y Y online CUSP
2000 Y Y Y online CUSP/TriNet
2001 - present Y Y Y online TriNet/SCSN - modern archival format