Journal of the Japan Society of Erosion Control Engineering, Vol.56,No.2,p.23-31,2003
The sediment-related disasters caused by the earthquake occurred in the offshore of Miyagi Pref. in May 2003 (prompt report)

Michiya IRASAWA, Kazuki MATSUMURA, Hiroshi KAWABE, Shinya HIRAMATSU, Motoyuki USHIYAMA, Yuji YASUDA

Abstract

An earthquake having 7.0 Magnitude (M) occurred at 18:24on June 26 2003in the sea offshore Miyagi. The earthquake caused damages in huge area of Tohoku district to houses, public facilities, farmland etc, and triggered many slope failures in Sanriku and Kitakami district. Particularly there were much damage in Iwate and Miyagi prefecture. However, the magnitude of earthquake is large, the damages are comparatively small. This may be considered that the period characteristic of this earthquake was relatively short. And as a thing peculiar to sediment-related disaster, a slope failure due to liquefaction occurred in the gentle slope of Tsukidate town. This area was artificial filled land developed for farmland, and the failure occurred at the filling land in a valley. An incline of the failed land was gentle, in less than 10 degrees. We suppose that liquefaction-phenomenon occurred by this earthquake, so the slope failure occurred in the gentle hills. This paper summarized the investigations related to the property to the earthquake damages, focused on slope failures, rock falls, cracks.

Key words:Tohoku district, Iwate and Miyagi prefecture, earthquake, sediment-related disaster, slope failure