Data Services Newsletter

Volume 7 : No 2 : June 2005

SeismoArchives: Seismogram Archives of Significant Earthquakes of the World


“… old seismograms, if properly interpreted, provide invaluable information on earthquakes in the past, and every effort should be made to save them, regardless of their quality, from possible loss and to make copies in an easily readable form.”

— Hiroo Kanamori (1988).

Background

The SeismoArchives are being constructed under the auspices of the Committee for the SeismoArchives Project of the International Association of Seismology and Physics of the Earth’s (IASPEI), in collaboration with the Data Management Center (DMC) of the Incorporated Research Institutions for Seismology (IRIS).

The main purpose of these online SeismoArchives is to preserve seismograms and related materials of significant earthquakes of the World in computer data files so that they are readily accessible online as source materials for research. In constructing an earthquake archive, we attempt to host relevant data and information of that earthquake in one Website.

Because no funding is yet available for constructing these SeismoArchives, we depend on volunteers and donors of data files and/or financial support for scanning analog seismograms that dated back to 1882. Although the IRIS DMC has been managing modern digital seismogram data since the 1980s, the bulk of the seismograms recorded by seismic observatories and networks for over 100 years are in analog form on either papers or microfilms.

Seismograms from the 1964 M9.2 Alaska event
Figure 1: Seismogram from the 1964 Alaska Earthquake

These analog seismograms (about 50 million worldwide) have been disappearing at an alarming rate. We are now concentrating on archiving a tiny fraction of the seismograms recorded by the Worldwide Standardized Seismograph Network (WWSSN) in the 1960s and 1970s (about 5 million seismograms on 70mm film chips), and by the Historical Seismogram Filming Project in the 1980s (about 0.5 million seismograms on microfilms for earthquakes prior to 1963).

SeismoArchives Website

The SeismoArchives project is hosted on the IRIS Web site at http://ds.iris.edu/seismo/

SeismoArchive web-based interface
Figure 2: The SeismoArchives custom Web interface developed at the IRIS DMC.

SeismoArchives are grouped into 2 major types: by individual earthquakes, and by special projects. Background information, including software (now in planning), is also included. To view the online archive, please click one of the following items.

  1. Archives by Individual Earthquakes
  2. Archives by Special Projects
  3. Background Information

SeismoArchives Search

A custom Google search tool is integrated into the archive. Try conducting a SeismoArchives search for “Chile” or “Alaska”.

Google

Future Plans

The USGS WWFC Pilot Scanning Project, containing approximately 30,000 scanned seismograms, will be integrated into the SeismoArchives with a web interface and search tool. This special project includes WWSSN seismograms of 156 nuclear events and 78 earthquakes from the 1960s and 1970s.

Over one hundred significant earthquakes and related materials, as well as software to aid using the computer files, will be available on the SeismoArchives Website in the future.

Contributors and Volunteers Are Needed

We welcome contributors of seismograms, data files, software, and relevant information of significant earthquakes of the world. Volunteers are needed to serve as “Archivists” for earthquake archives. Please contact Willie Lee: office office or home.

h2 More information

Explore the SeismoArchives website

by William Lee (United States Geological Survey) and Tim Knight (IRIS Data Management Center)

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