Atsushi Iwashita

Study of Disaster Information Extraction using C/L-Band SAR Interferometry

The object of this study is to consider the ground surface displacements that occurred due to the movement of Philippine sea plate movements in the adjacent area of Huatung Valley in eastern Taiwan. We have first performed differential SAR interferometry (D-InSAR) to clarify crustal deformation activity and estimated the displacement values by comparing GPS measurements to evaluate. According to the results by ENVISAT/ASAR interferometry. The calculated displacement values ranged between -1.4 cm and +1.4 cm, which coincide on the active fault area. It was clearly appeared that the northern part of Hualien city seem to sunk approximate 20 mm along to the slant range direction. We have also completed to generate L-band ALOS/PALSAR interferograms successfully: some topographic. It is expect to acquire and more detail processing of. Finally, we plan compare with GPS displacements at the hazardous areas.

Crustal deformation monitoring using repeat-pass interferometry in the vicinity of Hua-Tung Longitudinal Valley, Taiwan

Southwestern Ryukyu Arc and Eastern Taiwan region are characterized by subduction and collision of the Philippine Sea Plate and Eurasian Plate. Huatung Longitudinal Valley is a huge valley running between the cities of Hualian and Tainting in Eastern Taiwan with approximate length of 130 km. This valley is also located in between Central Mountain Range and Coastal Mountain Range. Since 1998, Tokai University has started to measure seismological activities with Dahan Institute of technology (DIT), a Taiwan Technology University, also measuring GPS and Electronic Distance Meter (EDM) data to monitor the crustal movement in the northern part of test area. We have performed a repeat-pass differential interferometric analysis using the ENVISAT/ASAR data. In addition, we propose a crustal movement extraction approach useful when insufficiency of the successful SAR image pairs.

Surface Topographic Analysis in Northern Part of HuaTung Valley, Taiwan

Southwestern Ryukyu Arc and Eastern Taiwan region is characterized by a collision and obduction of the Philippine Sea Plate against to Eurasian Plate. HuaTung Valley is a huge Longitudinal Valley running between the cities of Hualien and TaiTung approximately 130km length. Since 1998, our research group started to measure seismological activities and specific distances in the target area using GPS and EDM in cooperation with Taiwan Research group to study several geophysical phenomena expected to occur in this area. In 2007, we performed a Satellite repeat-pass Differential SAR Interferometry (D-InSAR) using ENVISAT/ASAR, and presented the surface deformation status in 2008 that the north part of the HuaTung Valley is sinking caused by Philippine Sea plate drifting northeastward. In this year (2009), we started to consider deformation features and add Fractal and Lineament Analysis. In this paper, we will provide some results. Also we will present the relation between surface fracture analysis and seismological activities.