Long-Period Horizontal Seismometer (WWSSN)
date: label: date made
content: 1961-1962
name: label: maker
content: Geotechnical Corporation
label: maker
content: W. F. Sprengnether Instrument Co.
notes: label: Description
content: 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.
label: Description
content: 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.
label: Description
content: 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.
label: Description
content: Ref: United States Coast and Geodetic Survey, <i>Instrumentation of the World-Wide Seismograph System, Model 10700</i> (Washington, D.C., 1962).
label: Description
content: W.F. Sprengnether Instrument Co., Inc., <i>General Discription (sic) Long Period Horizontal Seismometer</i> ([St. Louis], n.d.).
label: Description
content: W.F. Sprengnether Instrument Co., Inc., <i>Sprengnether Horizontal Component Seismometer, Series H</i> ([St. Louis], n.d.).
label: Description
content: Ta-Liang Teng, “Seismic Instrumentation,” in <i>Methods of Experimental Physics</i>, vol. 24 part B, <i>Geophysics</i> (1987), pp. 56-58.
label: Location
content: Currently not on view
place: label: place made
content: United States: Texas, Dallas
label: place made
content: United States: Missouri, Saint Louis
topic: label: related event
content: Cold War
setName: label: See more items in
content: Medicine and Science: Physical Sciences
label: See more items in
content: Seismographs
label: See more items in
content: Science & Mathematics
label: See more items in
content: Measuring & Mapping
creditLine: label: Credit Line
content: U.S. Geological Society
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1999.0275.04
label: catalog number
content: 1999.0275.04
label: accession number
content: 1999.0275
objectType: label: Object Name
content: seismometer
physicalDescription: label: Measurements
content: overall: 54 cm x 57 cm x 63 cm; 21 1/4 in x 22 7/16 in x 24 13/16 in