The purpose of these archives by projects
is to preserve scanned seismograms created by some
special projects. The scanned image files will be searchable by some simple
queries, and related materials will be available to aid the users. Seismograms
will be downloadable (in originally scanned resolution) from the IRIS Data
Volunteers and financial donors are welcome. Please
contact William H.K. Lee at: firstname.lastname@example.org.
1. The USGS WWFC Pilot Scanning Project
The World Wide Standardized Seismograph Network
(WWSSN) began operations in 1961.
One hundred twenty stations were installed, covering every continent. A station
3 short-period and 3 long-period seismometers, recording apparatus, radio-synchronized
crystal clock, and calibration controls.
Data were originally recorded on photographic
paper, then later on heat sensitive paper.
The original records were photographed at the WWSSN Data Center using
70 mm film
and stored by station and year on a 70 x 120 mm film chip. Lamont-Doherty
and the USGS Albuquerque Seismological Laboratory (ASL) each hold near-complete
chip sets of the WWSSN data. The slow degradation of these film chips has
prompted this pilot
project in 1999.
The film chips are black and white and have
been digitally scanned with a resolution of 3200 dpi.
The image has been cropped to exclude areas on the film chip which do not
contain the image of the
original record, however in all cases, the final product contains all of
the original photographed record.
The resulting grey-scale images have been saved at approximately 1/10th
of the original film chip size
as TIF files and then compressed using gzip. Enlarging the images
by a factor of 10 results in images
similar in size to the original analog record.
Use the Searchable Product Archive to find scanned seismograms
2. IASPEI Seismogram, Seismic Station Bulletin, and Marigram Scanning Projects
IASPEI sponsored projects were undertaken to scan original seismograms, station bulletins and copy marigram images.
Seismograms of the Reference station SJP were scanned at 500dpi, grayscale and are found in the reference station section of seismoarchives.
Station bulletins from the US Coast and Geodetic Survey Magnetic Observatory Seismological Reports for VQS, CHL, TUC, HON, and SIT and held at the library of the National Geophysical Data Center in Boulder, Colorado were scanned to complete seismic bulletin sets not already scanned or on microfilm. Those images are available here:
Cheltenham, Maryland (CHL, 1904-1924) (Cheltenham_1905-1924.pdf)
Honolulu, Hawaii (HON, 1921-1924) (Honolulu_1921-1924.pdf)
San Juan, Puerto Rico: SJP, 1926-1928 (San_Juan_1926-1928.pdf), 1929-1930 (San_Juan_1929-1930.pdf), 1946 (San_Juan_1946.pdf)
Sitka, Alaska (SIT, 1921-1924) (Sitka_1921-1924.pdf)
Tucson, Arizona (TUC, 1909-1924) (Tucson_1909-1924.pdf)
Vieques, Puerto Rico (VQS, 1903-1924) (Vieques_1903-1924.pdf)
Several bulletins from non-US stations were also scanned. They are from Argentina, Apia in Western Samoa, and Mauritius.
Argentina (1921-1923) (Argentina_1921-1923.pdf)
Apia, Western Samoa (1921-1937) (Apia_1921-1937.pdf)
Mauritius (1900-1909) (Mauritius_1900-1909.pdf)
Several thousand marigram images, many containing records of tsunami, were copied from DVDs held at the National Geophysical Data Center (NGDC) in Boulder, Colorado to be made available here. A very useful NGDC website linking these data to the NGDC tsunami database are here:
At this site you can search marigrams, find links to event information, and connects with National Geophysical Data Center tsunami event database maintained by Paula Dunbar.
Images were originally scanned at 600 dpi grayscale. A table containing station name, station coordinates (when available), date of marigram image, and NDGC DVD number is available here:
Link to marigram DVD List (Excel .xls file; marigram_DVD_list.xls)
This directory contains images of seismograms formally
stored by the Caltech in the Kresge Seismological Laboratory, Pasadena CA.
The images are a subset of the approximately 1 million paper records accumulated
from 1928 through the mid-1980’s. The images were scanned in 2009-2010
by Google in collaboration with UC Santa Cruz as part of the Google Books project.
Scans include fronts and backs of the paper records and are organized into
directories that each corresponds to an individual box in which the records
were originally stored at Kresge. The goal of this electronic library of seismograms
is to allow users to simulate the experience of going to the paper archives
and flipping through a box to find a record. The organization is imperfect
and the search engine non-existent, but the original records are now as accessible
to the world-wide user group as they once were to a small group of California
More (pdf version)
A Wiki site is now available for the Caltech Archive community to post information on known issues with the scanned Caltech historic seismograms. As users discover interesting events, problems with the scans or other issues, posts should be made to this page. This information is meant to supplement the pdf documentation provided in the scan home directory.
Go directly to the Caltech Archive
Supported by volunteers and financial donors
Last updated: August 29, 2011