Responses to recent great earthquakes and ensuing tsunamis in Sumatra, Chile and Japan with the severe loss of life, massive damage to infrastructure, and major economic and social consequences demonstrate that our ability to rapidly evaluate the magnitude and source of catastrophic earthquakes using traditional seismic methods is limited. The latest example is the 2011 Mw 9.0 Great East Japan earthquake where it took decision makers more than 20 minutes to ascertain that a truly devastating event was taking place. This hindered efforts to mitigate the disaster and may have contributed to unnecessary loss of life and to the severity of the nuclear disaster caused by the subsequent tsunami. This one-year feasibility proposal from Scripps Institution of Oceanography and UCSD’s Jacobs School of Engineering exploits a new interdisciplinary Earth observation type: real-time 3-D displacements based on an optimal combination of GPS and accelerometer network data that span the full spectrum of ground deformation from the very-high frequencies to the permanent deformation. These observations of millimeter precision can improve early warning systems for large earthquakes, the timeliness of earthquake characterization by an order of magnitude (~2 minutes), and rapidly provide the full bandwidth of excitation responses for large engineered structures (bridges, tall buildings, dams, hospitals, airports), including translational and rotational motions. A confident warning of structural damage can be interpreted by decision makers for rapid evacuation and structural tagging to improve disaster mitigation. We will work with partners in the public sector, at the USGS and Caltrans, to improve the procedures and protocols used to rapidly ingest earthquake source parameters and assess the response of near-fault structures, using the existing GPS/seismic network in southern California as a test bed. The feasibility study also tests a prototype Geodetic module and low-cost MEMS accelerometer package that may be commercialized in subsequent years.