- 公益社団法人 日本地震学会
- 地震 第2輯 (ISSN:00371114)
- vol.32, no.1, pp.57-73, 1979-03-25 (Released:2010-03-11)
The Great Kanto earthquake, 1923, triggered a catastrophic debris flow which devastated the village of Nebukawa with a loss of 300 to 400 lives. The buried area at Nebukawa is determined by synthesizing eyewitness accounts, photographs, the character of surface soils, etc. The moment of rushing at Nebukawa is estimated at about 5 minutes after the mainshock onset from the eyewitness accounts and aftershock records. The temporal change in topography in the mountain region is investigated by comparing topography maps prior and after the earthquake, and a probable source of the debris flow is assumed at a large depressed area, Obora about 4km upstream Nebukawa. The grain-size distributions of the debris-flow deposits and those of mountain soils are also consistent with this assumption.