About USArray > Why

Mission

To collect seismic data and allow public access to them in near real time to further our understanding of the earth and of tectonic processes.



Ideal Geologic Laboratory

The North American continent displays the full spectrum of plate tectonic processes, making it a great place to study both active and ancient structures:
1. active plate convergence and volcanism in the subduction zones of Cascadia and the Aleutians
2. active shearing and earthquake generation along the San Andreas Fault zone
3. active intraplate extension and gravitational collapse of the Basin and Range
4. the ancient Appalachian Mountains, for relating continental deformation to past mountain building



Practical Applications

The plate boundary of western North America -- the San Andreas Fault system, the Cascadia and Aleutian subduction zones, and the Intermountain seismic belt -- includes significant regions of earthquake, volcanic, and landslide hazards. All EarthScope components provide data that bear directly on the assessment and mitigation of the risks from these hazards. These data will advance our knowledge of the mechanics of volcanic eruption and earthquake generation, and increase the possibility of earthquake prediction. As the Transportable Array crosses the nation, there will be opportunities for EarthScope scientists to interact with federal and state agencies involved in regional mapping, education, public policy, and resource assessment. The Flexible Array component of USArray will be an important tool for probing the geological framework of the continental crust and the structural details of sedimentary basins. Subsurface maps, developed from various types of geological investigations and merged with high-resolution seismic images, will be an invaluable resource in collaborative and multidisciplinary research projects related to the assessment and exploitation of groundwater, mineral, and energy resources.



Why couldn't we do this type of experiment before?

Seismology is a relatively new science. Geologic mapping of the past 150 years, combined with seismic advances in the 1900s, provided framework for looking beneath Earth's surface. Because of technical constraints, 20 years ago USArray was a dream. It is now a reality because we have three necessary components:
1. high-precision seismometers
2. real-time data transmission (now possible with satellites, cell phones, and Internet)
3. ability to store and analyze the monumental mountain of data recorded

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HIGHLIGHTS

Accessing data
Data transmitted from the USArray seismometers can be accessed by anyone. Following large earthquakes, the IRIS and USGS Web sites offer near-real-time earthquake information for scientists, emergency workers, and the curious public.


EarthScope is a partnership extending throughout the Earth science community, including more than 100 universities, the National Science Foundation, US Geological Survey, National Aeronautics and Space Administration, Department of Energy, regional seismic networks and state geological surveys.