11:30 AM - 11:45 AM
[SSS08-15] Generation mechanisms of large-scale fissures in Asodani area accompanied by 2016 Kumato earthquake through drilling investigation and sample analysis
In order to elucidate the generation mechanism of the fissures, we conducted a drilling survey in the center of one of the horizontal movement zone. As a result, the regions with northern displacement corresponded to those with thick soft sediments, and the thickness greatly changed beneath the regions with northern displacement.
X-ray photos of the cores were taken to investigate the internal structure of the sediments. They can clearly image the thin layers of sands or volcanic ash in slit-rich layers. One of the interesting features for the X-ray photos was that the dips of the thin layers changed greatly at depths of 43.5-44.5 m and 55-56 m. This suggests that the sediments deformed at these depths. We will investigate the mechanisms and ages of this deformation in the future.
Acknowledgements: Discussion with Dr. Satoshi Goto in Yamanashi University is useful. We are financially supported by collaborative research program of DPRI, Kyoto Univ. (28-U06, 29-A04).