JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Oral

S (Solid Earth Sciences) » S-SS Seismology

[S-SS07] [EE] Surface Ruptures During Earthquakes: Mapping, Analyses, and Hazard Assessment

Wed. May 24, 2017 3:30 PM - 5:00 PM Convention Hall A (International Conference Hall 2F)

convener:Koji Okumura(Graduate School of Letters, Hiroshima University), St?phane Baize(Institut de Radioprotection et de S?ret? Nucl?aire), Nobuhisa Matsuta(Okayama University Graduate School of Education), Takashi Azuma(National Institute of Advanced Industrial Science and Technology), Chairperson:Koji Okumura(Graduate School of Letters, Hiroshima University)

4:00 PM - 4:15 PM

[SSS07-14] Earthquake-induced surface deformations in a small mud volcano: multi-temporal high-definition measurements using TLS and UAS-SfM

*Yuichi S. Hayakawa1, Shigekazu Kusumoto2, Nobuhisa Matsuta3 (1.Center for Spatial Information Science, The University of Tokyo, 2.University of Toyama, 3.Okayama University)

Keywords:TLS, SfM-MVS photogrammetry, UAS, Point cloud, Digital Elevation Model, Cracks

Tectonic signals are often found in mud volcanoes which are formed both in the land and undersea areas. Earthquakes often enhance the activities of mud volcanoes, including the surface deformations, mud eruptions, and gas emissions. Extensional stresses by upcoming underground pressures of liquid mud and gas may result in the formation of surface ruptures on mud volcanoes. Subtle changes of such surface deformations can be detected by the use of high-definition topographic measurements, including terrestrial laser scanning (TLS) and unmanned aerial system-based structure-from-motion multi-view stereo photogrammetry (UAS-SfM). The Murono mud volcano, located in Niigata Prefecture in north-central Japan, is an ideal test site for the measurements because of its small size and frequent deformations by strong earthquakes in this region. The spatiotemporal variations in the surface morphology have been explored in the mud volcano using TLS. While the TLS approach is suitable for accurate three-dimensional measurements of the surface morphology, the UAS-SfM approach is capable of acquiring visual images of the ground surface from which cracks can be readily extracted and mapped with a certain accuracy. The fusion of TLS and UAS-SfM point cloud data enables to enhance the accuracy of the UAS-derived data. We demonstrate a case study of the crack mapping using these data, as well as a result of numerical simulation of crack formations based on the pressure distribution by earthquakes.