Synthetic Aperture Radar (SAR) is the technique to obtain ground surface images using microwave that is emitted from and received on the antenna. Previous studies revealed that the 2011 off the Pacific coast of Tohoku earthquake induced landslides by field survey or using aerial photographs interpretation. This study also found that the earthquake induced landslide surface deformation in wide area of eastern Japan using Advanced Land Observing Satellite (ALOS)/Phased Array type L-band SAR (PALSAR) data; the deformation area which is 2.25 ha and more was detected, and the number of the detected areas (polygons) on the mountain slope is 22. It is estimated that ca. 300 gal was the minimum peak ground acceleration triggering landslide surface deformation. Focusing on the detected deformation area, the widest area among the geologic units was 952.5 ha, covered by Pleistocene volcanic and pyroclastic rock. Such the deformation is not only explained by reactivation of landslide mass but also controlled by geological structure inside the Caldera landform. Examples of the deformation area are shown with field survey and in-situ deformation measurement results.
With intention of future construction of non-tectonic structure geology, this paper discusses the geological viewpoint of landslide being concerned with observation, diagnosis and so on, and picks up important issues on analysis methods of map-, outcrop-and rock-scaled structures of landslide.