• NAPA Earthquake Response is using Satellite Radar, UAVSAR and GPS

    NASA data and expertise are proving invaluable in California's ongoing response to the 24 August 2014 magnitude 6.0 earthquake in Napa Valley, northeast of San Francisco. The quake was the strongest to occur in the San Francisco Bay Area in a quarter-century and caused significant regional damage. Analyses by scientists at NASA's Jet Propulsion Laboratory, Pasadena, California, of airborne data from NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR), GPS data and radar imagery from the Italian Space Agency's COSMO-SkyMed satellites, are revealing important details of how the ground deformed in the region and the nature of the fault movements. In addition, a NASA-funded disaster decision support system has provided a series of rapid-response data maps to decision makers at the California Earthquake Clearinghouse. Those maps are being used to better direct response efforts.

     

    Satellite Radar

    NASA JPL scientists and their Italian colleagues analyzed radar images from the Italian space Agency's (ASi) COSMO-SkyMed satellites to calculate a map of the deformation of Earth's surface caused by the earthquake. The colors indicate the amount permanent surface movement that occurred almost entirely due to the earthquake, during the one-month interval between two COSMO-SkyMed images, one before and one after the earthquake. Black arrows on the embedded map image (left image of top right section) show the measured permanent horizontal movement measured by GPS. The second radar map (right image of top right section) is based on the same data as the first map, but is shown in a way that highlights very small-scale ground deformation and evidence of the fault rupture visible on Earth's surface.

     

    UAVSAR and GPS

    A comparison of data collected three moths before the earthquake and data five days after the magnitude 6.0 South Napa earthquake showed that the surface rupture was more complex than originally anticipated, with motion on multiple strands of the fault near the epicenter. The exqusite detail of the UAVSAR imagery (bottom right image) provides local, state, and federal agencies with the exact location of the fault traces that shifted during the earthquake and how they relate to levees, buildings, roads, and other vital infrastructure, as well as to help provide a fundamental understanding of earthquakes processes.

     

    Rapid Decision Support

    InLET (Internet-based Loss Estimation Tool), provides immediate post-event estimates of casualties and building damage. The Strain Magnitude Map (left image, top) provides an early estimate of where ground deformation has occurred, and where damage may be localized. The Aftershock Forecast Map (left image, bottom) highlights areas where aftershocks are likely to occur -- warmer colors represent higher risk and cooler colors lower risk. Using critical infrastructure overlays with damage estimates, decision makers can direct response efforts. For example, each map shows critical facility that was predicted to have sustained damage that can later be verified in the field.