U.S. Geological Survey       National Strong-Motion Project



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The U.S. Geological Survey National Strong-Motion Project (formerly titled the National Strong Motion Program) has the primary Federal responsibility for recording each damaging earthquake in the United States on the ground and in man-made structures in densely urbanized areas to improve public earthquake safety.  The NSMP maintains a national cooperative instrumentation network, a national data center, and a supporting strong-motion data analyses and research center in support of this responsibility.

Mission || History || Components ||  Products || Staff


The NSMP is dedicated to improving public earthquake safety through the fulfillment to meet the national responsibility of the USGS for coordination, acquisition, rapid dissemination and interpretation of strong-motion recordings of each damaging earthquake in the United States.  Strong-motion recordings of damaging U.S. earthquakes in densely urbanized areas are critical for improvements in the design of earthquake-resistant structures and efforts to reduce potentially catastrophic amounts of property loss ($~200 billion) and life loss (~5,000 deaths) expected for some future earthquakes.  The recordings are fundamental for understanding and characterizing the physics of seismogenic failure, the generation and propagation of damaging ground motions, and the shaking performance of structures. The consistency and quality of strong-motion recordings produced by the Project are well-illustrated by these Selected Accelerograms, which were recorded during significant earthquakes that occurred since 1933.


Strong-motion recording in the United States has roots in the World Engineering Congress that convened in Tokyo in 1929. American engineers returned from these meetings convinced there was an immediate need for the United States to develop a rugged seismograph able to record potentially damaging ground motions and to monitor the response of critical structures during strong local earthquakes. In 1931, Congress allocated additional funds to the U.S. Department of Commerce, Coast and Geodetic Survey (C&GS) for establishment of an engineering seismology program, including the development of a strong-motion seismograph (accelerograph), and the implementation and operation of a national strong-motion network. The first accelerograph, a modification of the Wood-Anderson seismograph, was designed by the National Bureau of Standards in the Department of Commerce. In 1932, the C&GS set up the Seismological Field Survey in California with headquarters in San Francisco.

The first U.S. accelerographs were installed in southern California in the summer of 1932.  Following the successful recording of strong-ground shaking during the 1933 Long Beach earthquake, the network was expanded to more than 50 instruments in the western United States including some at the upper levels of buildings in the Los Angeles and San Francisco areas.  The C&GS operated all strong-motion instrumentation in the United States regardless of ownership, but in 1963 the first "modern" accelerograph was developed leading to the establishment of instrumentation programs by many other organizations.   Network responsibilities were transferred to the National Oceanic and Atmospheric Administration's earthquake program in 1970.  By 1972 the network included 575 accelerographs at permanent stations located throughout the United States and in Central and South America.  In 1973 (with National Science Foundation funding), the entire strong-motion program was absorbed by the U.S. Department of the Interior, U.S. Geological Survey, as part of the National Earthquake Hazards Reduction Program.

The NSMP and it's predecessors have evolved over more than eight decades.  At times some 1200 stations have participated in the National Strong-Motion Network (NSMN).  The NSMP currently operates over 1,000 strong-motion instruments at over 700 permanent stations (stations) located in 33 States and the Caribbean [Distribution By State].  The NSMN is primarily the result of cooperative efforts with many other Federal, State, and local agencies, private companies, and academic institutions [Client List]. 

The NSMP is part of the USGS Earthquake Hazards Program, and its main campus location which is at the Menlo Park Science Center in northern California.  NSMN Operations activities are coordinated from the Menlo Park office and a field office in Pasadena, California. [STAFF].

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In 2013, the NSMP was merged with the Northern California Seismic Network (NCSN) to form the Earthquake Monitoring Project managed by David Oppenheimer.  The NSMP staff conduct the tasks as outlined below in each of the two major components of the Project concerned with Data Acquisition and Data Management.

1)   NSMP Data Acquisition

2)   NSMP Data Management

Go to Personnel Directory (staff listed alphabetically and by location with telephone numbers)
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General major products using the data acquired and managed by the NSMP include:

This page was last updated on May 13, 2014.

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