Observation Results of ALOS/PALSAR relating to the magnitude 6.3 Earthquake in Central Italy
On April 6, 2009 (UTC), magnitude 6.3 earthquake occurred in central Italy. The Japan Aerospace Exploration Agency (JAXA) performed an emergency observation on April 22, 2009 using the Phased Array Type L-band Synthetic Aperture Radar (PALSAR) installed on the Advanced Land Observing Satellite (ALOS) to determine the state of damage caused by the earthquakes. In this report, we conducted differential interferometric SAR (DInSAR) analysis to detect crustal deformation using the data acquired on April 22, 2009 and July 20, 2008.
Figure 1 left is an interferogram generated from PALSAR data acquired before and after the earthquake using the DInSAR technique. A color pattern illustrates changes of satellite-ground distance for the period. Figure 1 right is a PALSAR amplitude image acquired after the earthquake indicating an observation field of 150km from south to north. There is an eyed pattern of color fringe in east of the epicenter in the interferogram. This pattern is interpreted to represent a 17.7cm extension of satellite-ground distance at the center of the fringe. This indicates a subsidence caused by seismic faulting of southwest-dipping normal fault.
JAXA plans to continue ALOS observations of the afflicted area in central Italy.
The color changes from green, blue, red, yellow, and back to green indicating an extension of the satellite-ground distance, and one color cycle = 11.8cm.