abstract:USArray is one of the three components of the Earthscope project [the other two being the Plate Boundary Observatory (PBO) and the San Andreas Fault Observatory at Depth (SAFOD)], funded by the National Science Foundation and being constructed, operated, and maintained as a collaborative effort with UNAVCO Inc., the Incorporated Research Institutions for Seismology (IRIS), and Stanford University, with contributions from several other national and international organizations.