USArray, which is part of the EarthScope experiment, is a 15-year program to place a dense network of permanent and portable seismographs across the continental United States. The seismographs record the energy released by earth movements, from the rumbling of cars on the highway to the seismic waves released by the hundreds of earthquakes that occur around the world every day.
By analyzing the records of earthquakes obtained from this dense grid of seismometers, scientists can learn about Earth structure and dynamics and the physical processes controlling earthquakes and volcanoes.
The USArray facility consists of four major components: a Transportable Array, a Flexible Array, a Reference Network, and a Magnetotelluric Facility. Click on any of the links below to learn more about USArray programs. Both the Transportable Array (TA) and Flexible Array (FA) programs are supported by the IRIS PASSCAL Instrument Center, and are described by numerous articles on this website.
A Flexible Array of 325 broadband stations, 100 short period stations, and 1700 active-source stations permits high-resolution studies within the broader-spaced Transportable Array, allowing a range of specific targets to be addressed in a focused manner.
A Magnetotelluric Facility of seven permanent and 20 portable sensors, installed in conjunction with USArray seismic instrumentation, records naturally occurring electric and magnetic fields.
