USArray is the working name for an idea and for an imagined research tool and facility. The idea is that a dense deployment of seismological instruments across the continental US would allow us to collect data that could help us understand the evolution and deeper geological structure of the North American continent. The tool and the facility are the actual seismometers and the associated infrastructure required for data collection and distribution.
The facility is currently conceived to consist of two main parts: (1) a collection of several hundred seismographs configured in a telemetered transportable array, and, (2) a dense network of permanent broad band stations providing uniform coverage across the Continental US. In a program of temporary USArray deployments, each of several months' duration, the transportable array would be used to cover the entire continental US over a period of approximately 10 years. The permanent USArray network would evolve in close cooperation with USGS and regional network operators with installations and upgrades of broad band instrumentation in areas of limited coverage, and with an emphasis on high-quality data and efficient data distribution.