ALOS-2/PALSAR-2 Observation Results of the 2015 Nepal Earthquake (2)
- ALOS-2/PALSAR-2 observed eastern Nepal to detect the surface deformation associated with the earthquake.
- Detected deformation extends to approximately 170 km east-southeast from the epicenter.
- The extension and shortening of the satellite-ground distance were observed at the southern and northern part of the fault, respectively.
The Japan Aerospace Exploration Agency (JAXA) has been performing observations with the Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) aboard the Advanced Land Observing Satellite-2 (ALOS-2, "DAICHI-2") for monitoring the effects of an earthquake struck Nepal on April 25, 2015 (local time). The emergency observations were requested from Sentinel Asia and the International Charter.
We applied an interferometric analysis to the PALSAR-2 data obtained with ScanSAR mode before (May 31, 2015) and after (April 28, 2015) earthquake to detect the deformation associated with the earthquake. The ScanSAR interferometry, which has been made possible by the highly synchronized observation beams of PALSAR-2, enable us to monitor over 350 km swath at once.Figure 1 shows the whole interferogram. Colored fringes denote the change of the line-of-sight (LoS) distance (distance between the satellite and the ground) between April 28 and March 31. In the lower left part (the east from Kathmandu), fringes possibly caused by the earthquake are visible. Large fringes in the right part of the figure are probably not tectonic fringes but remaining orbital fringes*1 and ionospheric effects*2.
JAXA will continue the observation at this area and the next interferometric observation covering the epicenter is now scheduled for May 2, 2015 (GMT). JAXA will provide PALSAR-2 images and results to relevant organizations and this website.