Contact Person: Dr. Ioannis Papoutsis
On April 25 2015, a Mw 7.8 earthquake hit Nepal. The epicenter was east of the district of Lamjung and the hypocenter was at a depth of approximately 15 km. The event killed more than 8,800 people and injured more than 23,000. Kathmandu, Nepal’s capital city was heavily inflicted suffering massive losses in human lives, damages in critical infrastructures and cultural heritage assets and thereby inducing major economic losses at a national scale.
NOA operates ESA’s Sentinel Collaborative Ground Segment and maintains the BEYOND Center of Excellence for monitoring natural disasters from space. Shortly after the earthquake two Sentinel-1 Synthetic Aperture Radar images were acquired, one before the devastating earthquake and one after. They were combined to form an interferogram that depicts ground deformation due to the earthquake. The map reveals the overall impact of the earthquake. A large amount of fringes is evident, each one corresponding to 2.8 cm of ground displacement in the direction of the satellite. More than one meter of total deformation is observed. As a secondary phenomenon, the earthquake triggered several landslides north-northwest of the epicenter, which are also shown in the map.
Sentinel-1 Interferogram of the Nepal Earthquake on 25/04/2015
This work highlights the operational capabilities of BEYOND, upscaled and triggered by the exploitation of the Sentinel Collaborative Ground Segment, for rapidly providing stakeholders with valuable information concerning ground displacement magnitude, pattern and extent following major earthquake events. At a subsequent phase, the interferometric information can be used by scientists to estimate key fault parameters and interpret the underlying geophysical processes towards estimating the seismic potential of the area.
Direct access to Sentinel data coupled with the advanced processing capacities, allows BEYOND to rapidly respond to future catastrophic events by timely providing a set of products to support disaster management and risk assessment. Such capacity is exercised within the CEOS Seismic Platform initiative, GEO’s Disaster Task, and the Copernicus EMS programme.