Long-Period Vertical Seismometer (WWSSN)

Working at the Lamont Geological Observatory, a Columbia University facility in Palisades, N.Y., Frank Press and his mentor, Maurice Ewing, developed seismometers that responded to surface waves of long-period and small-amplitude, whether caused by explosions or by earthquakes. The first long-period vertical seismometer at Lamont came to public attention in early 1953 with news that it had recorded waves from a large earthquake that had recently occurred at Kamchatka, in the Soviet Union. A painting of a subsequent but similar Lamont instrument appeared on the cover of Scientific American in March 1959.
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 WWSSN stations had an instrument of this sort. This example was used in Junction City, Tex. 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 small shop in St. Louis, Mo., that specialized in seismological apparatus.
Like other long-period vertical seismometers developed at Lamont, this one was built around a “zero-length spring” of the sort that had been proposed in 1934 by Lucien LaCoste, a graduate student in physics at the University of Texas, and later incorporated into the gravity meters manufactured by LaCoste & Romberg.
Ref: United States Coast and Geodetic Survey, Instrumentation of the World-Wide Seismograph System, Model 10700 (Washington, D.C., 1962)
Ta-Liang Teng, “Seismic Instrumentation,” in Methods of Experimental Physics, vol. 24 part B, Geophysics (1987), pp. 56-58.
Currently not on view
date made
W. F. Sprengnether Instrument Co.
place made
United States: Missouri, Saint Louis
overall: 25 in x 15 in x 26 in; 63.5 cm x 38.1 cm x 66.04 cm
ID Number
catalog number
accession number
Credit Line
U.S. Geological Survey
related event
Cold War
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Science & Mathematics
Data Source
National Museum of American History


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