Sentinel-1A Satellite: Transforming the analysis of earthquake data
We’ve previously written about the launch and progress of the Sentinal-1A satellite, part of the European Union’s Copernicus earth observation project. Although still being commissioned and not yet in full production mode, the satellite recently provided radar imagery from Northern California captured before and after the Napa Valley earthquake on 24 August.
Using a technique known as ‘Synthetic aperture radar interferometry’, two images of the same area were compared to identify areas of significant change. Changes to the ground surface modify the reflected radar signal detected by the satellite, and those modified signals can be plotted as an ‘interferogram’ (Source: Radar vision maps Napa Valley earthquake.) The result is both colourful and striking; the fault responsible for the 6.0 earthquake was confirmed as the West Napa Fault, and both the scale and the extent of the surface rupture was immediately apparent.
Imagery like these examples captured for the Napa Valley quake looks set to transform how scientists and data analysts map and respond to earthquakes. With the launch of second Sentinel satellite (1B) in 2016, the imagery update cycle will be reduced from 12 to 6 days. The timely and open publication of high resolution data to support activities on the ground and post quake analysis after each event, should provide unprecedented monitoring of the Earth’s surface.