New satellite maps out Napa Valley earthquake
Scientists have used a new Earth-observation satellite called Sentinel-1A to map the ground movements caused by the earthquake that shook up California's wine-producing Napa Valley on 24 August 2014. This is the first earthquake to be mapped by the European Space Agency’s (ESA) new satellite and demonstrates the capabilities of the Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET) in analysing its observations quickly. COMET Director, Professor Tim Wright, from the School of Earth and Environment at the University of Leeds, said: “This successful demonstration of Sentinel-1A marks the beginning of a new era for our ability to map earthquakes from space. COMET scientists are building a system that will routinely provide results for all continental earthquakes, as well as mapping the slow warping of the ground surface that leads to earthquakes. Professor Andy Hooper, a member of the COMET team from the School of Earth and Environment at the University of Leeds, added: "This satellite represents a sea change in the way we will be able to monitor catastrophic events, such as earthquakes and volcanic eruptions, due to its systematic observation strategy." Sentinel-1A was launched on 3 April 2014, but it only reached its final operational orbit on 7 August. The pre-earthquake image was acquired on that day. By comparing it with an image acquired on 31 August, COMET collaborators Dr Yngvar Larsen, from the research institute Norut in Norway, and Dr Petar Marinkovic, from PPO.labs in the Netherlands, created a map of the surface deformation – called an ‘interferogram’– caused by the magnitude 6.0 earthquake.
