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[MIS34-09] Characteristics of landslide disaster induced by the 2016 Kumamoto earthquake in and around Minamiaso Village, southwestern Japan
Keywords:the 2016 Kumamoto earthquake, landslides, debris avalanches, tephra deposits
At the post-caldera central cones of Aso Volcano, the April 16, 2016 earthquake-induced landslides occurred not only on steep slopes but also on slopes gentler than 10°. They occurred in unconsolidated superficial tephra deposits overlying lavas and agglutinates, and the thickness of the slides usually ranged from 4 to 8 m. The sliding masses traveled long distances (<600 m), comparing to small differences in elevation. The deposits were composed of tephra blocks of a few meters and there was no evidence that they were transported by water. These facts suggest that some landslides mobilized rapidly into debris avalanches, traveling a few hundred meters. The associated debris avalanche resulted in five casualties and severe damages of houses at the foot of Takanoobane lava dome.
The characteristics of the April 16, 2016 earthquake-induced landslides are different from those of rainfall-induced landslides in July 2012, June 2001 and July 1990 at Aso Volcano, and provide important information for preventing or mitigating future landslide disasters in the Aso caldera region.