Poster

[GM-P-01] Surface displacement based on InSAR analysis and seismic damage associated with the 2016 Kumamoto Earthquake

*Yoshiya Oda¹, Nanako Yokota¹, Hiroyuki Azuma¹ (1. Tokyo Metropolitan University (Japan))

Effects of surface geology on seismic motion is one of the most important factors to understand cause of house damages during a large earthquake. In fact, many of house damages could be explained by effects of surface geology. However, it is also fact that there are house damages unexplained by surface geology. One possibility of the cause is the surface displacement such as surface fault and land slide associated with an earthquake. We have, therefore, estimated surface displacement of Mashiki Town, the focal area of the 2016 Kumamoto Earthquake, based on InSAR analysis using ALOS-2/PALSAR-2 data before and after the 2016 Kumamoto Earthquake.
First, we compared between surface displacements based on InSAR analysis with surface faults detected from geomorphological observation. The surface displacements in Mashiki Town were very complex and many of them are considered to corresponded to the surface faults. Then we compared surface displacements at some area in Mashiki town. As the results, we found that there is locally damaged area in where surface geology is nearly homogeneous but surface displacement estimated from InSAR analysis is inhomogeneous. Although this surface displacement could be caused by damaged houses, InSAR analysis could be one way to find the cause of the seismic damage.