Strong-motion recordings of damaging earthquakes in densely urbanized areas are critical for designing earthquake-resistant structures to reduce property loss and casualties from future earthquakes. The recordings also are fundamental for understanding and characterizing the physics of earthquake rupture, the generation and propagation of damaging ground motions, and the shaking performance of structures.
The USGS National Strong-Motion Project (formerly titled the National Strong Motion Program) has the primary Federal responsibility for acquiring strong motion records of significant earthquakes in the United States recorded by sensors placed in the ground and in man-made structures.
The USGS monitors and reports on earthquakes, assesses earthquake impacts and hazards, and conducts targeted research on the causes and effects of earthquakes. We undertake these activities as part of the larger National Earthquake Hazards Reduction Program (NEHRP), a four-agency partnership established by Congress.