Long-Period Horizontal Seismometer (WWSSN)

Description
Working at the Lamont Geological Observatory, a Columbia University facility in Palisades, N.Y., Frank Press and his mentor, Maurice Ewing, designed seismometers that responded to surface waves of long-period and small-amplitude whether caused by explosions or by earthquakes. Their horizontal seismometer was of the “garden-gate” form: here, the horizontal boom attaches to the lower end of a vertical post, and a diagonal wire extends from the upper end of the post to the outer end of the boom. The first example was installed in 1953.
This example was made for the World Wide Standard Seismological Network. Established in 1961, the WWSSN was designed to detect underground nuclear tests, and generate valuable information about the earth’s interior and its dynamic processes. The WWSSN was a key component of VELA Uniform, a Cold War project that was funded by the Advanced Research Projects Agency (ARPA), a branch of the Department of Defense. It was managed by the U.S. Coast and Geodetic Survey and then by the U.S. Geological Survey. That agency transferred this instrument to the Smithsonian in 1999.
Each of the 120 stations in the WWSSN had two horizontal seismometers of this sort (one to capture the east-west component of the earth’s motions, and one to capture the north-south component). This example was used Junction City, Tx. It would have been linked to a matched galvanometer (such as 1999.0275.09) and a photographic drum recorder (such as 1999.0275.10). The “Sprengnether Instrument Co.” signature refers to a firm in St. Louis, Mo., that specialized in seismological instruments.
Ref: United States Coast and Geodetic Survey, Instrumentation of the World-Wide Seismograph System, Model 10700 (Washington, D.C., 1962).
W.F. Sprengnether Instrument Co., Inc., General Discription (sic) Long Period Horizontal Seismometer ([St. Louis], n.d.).
W.F. Sprengnether Instrument Co., Inc., Sprengnether Horizontal Component Seismometer, Series H ([St. Louis], n.d.).
Ta-Liang Teng, “Seismic Instrumentation,” in Methods of Experimental Physics, vol. 24 part B, Geophysics (1987), pp. 56-58.
Location
Currently not on view
Object Name
seismometer
date made
1961-1962
maker
Geotechnical Corporation
W. F. Sprengnether Instrument Co.
Measurements
overall: 54 cm x 57 cm x 63 cm; 21 1/4 in x 22 7/16 in x 24 13/16 in
place made
United States: Texas, Dallas
United States: Missouri, Saint Louis
ID Number
1999.0275.04
catalog number
1999.0275.04
accession number
1999.0275
subject
Measuring & Mapping
Science & Mathematics
Seismographs
event
Cold War
See more items in
Medicine and Science: Physical Sciences
Seismographs
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
U.S. Geological Society

Visitor Comments

Add a comment about this object

**Please read before submitting the form**

Have a comment or question about this object to share with the community? Please use the form below. Selected comments will appear on this page and may receive a museum response (but we can't promise). Please note that we generally cannot answer questions about the history, rarity, or value of your personal artifacts.

Have a question about anything else, or would you prefer a personal response? Please visit our FAQ or contact page.

Personal information will not be shared or result in unsolicited e-mail. See our privacy policy.

Image CAPTCHA
Enter the characters shown in the image.