USGS Earthquake Hazards Program

	Borehole Geophysics and Rock Mechanics Using borehole geophysical measurements in conjunction with laboratory studies, scientists study heat flow, stress, fluid pressure, and the mechanical behavior of fault-zone materials at seismogenic depths to yield improved models of the earthquake cycle.
	Crustal Deformation Plate motion produces distortion or deformation in the surface of the earth near active faults. Several techniques are used to measure this deformation, including GPS, 2-color Electronic Distance Meters (EDMs), strain meters, magnetometers, tilt meters, and water level monitors.
	Earthquake Geology & Paleoseismology Geologists learn about future earthquakes by studying evidence of past earthquakes--landforms produced by earthquake folding and faulting of the ground surface or sediments deposited in response to such deformation. When such evidence can be dated by radiocarbon or other methods, earthquake histories over thousands of years can be reconstructed.
	Hazards All of the research into where, how, when, and why earthquakes occur feeds into determination of the national seismic hazard maps. Scientists use the results of research in probability determinations for the National Seismic Hazards Map. Regional studies supplement the national maps. National Seismic Hazards Map
	Seismology and Earth Structure The locations of earthquakes reveal where active faults are located and where faults may be "locked." Studies of the waves from these earthquakes help map the structure of the Earth's crust, the orientation of stresses in it, and the movement of the faults within it.
	Strong Motion Seismology, Site Response, and Ground Motion Near large earthquakes, seismic waves have large amplitudes. Studying this strong shaking requires specialized sensors and produces information used in developing building codes and in designing earthquake-resistant structures such as buildings, bridges, and highways.

U.S. Department of the Interior, U.S. Geological Survey
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Last modification: Wednesday, 04-Sep-2002 16:26
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