Airborne Laser and Ground Survey of the Surface Ruptures Associated with the 2016 Kumamoto Earthquake Sequence, Central Kyushu, Japan.

Abstract

An investigation of surface ruptures was conducted with a combination of an airborne laser survey and a ground survey around Mashiki-town. In addition to the result of the ground survey, by comparing the data between before and after the main shock obtained from the airborne laser survey, the intermittent surface ruptures were found along Futagawa fault and Kiyama fault as known Futagawa-Hinagu fault zone. Then when the obtained surface ruptures and the known active fault trace were compared, we found that both do not much completely. On the other hand, we were continuously able to clarify the displacement around the surface ruptures with the difference chart of the data between before and after the main shock obtained from the airborne laser survey. Finite difference analysis of the airborne laser survey is an effective measure for an investigation of surface ruptures and can conduct an extensive survey swiftly. However, there is much information which can be obtained by a ground survey only. By combining an airborne laser survey and a ground survey, a prompt and high-precision survey can be conducted.