Journal of Natural Disaster Science

A CATASTROPHIC DEBRIS AVALANCHE INDUCED BY THE 1923 GREAT KANTO EARTHQUAKE

Yoshimasa KOBAYASHI
Associate Professor, Faculty of Science, Kyoto University

(Received 4 April, 1985 and in revised form 3 Dec., 1985)

Abstract

A major debris avalanche triggered by the Great Kanto Earthquake of 1923 devastated the village of Nebukawa with a loss of 300 to 400 lives. The devastated area at Nebukawa was determined from eyewitness accounts and other evidence. Topographical changes during the period spanning the event indicate that the source area was at Obora. The grain-size distributions of soils present in the devastated part of Nebukawa and the mountain support the claim for the Obora source. The speed of the rock avalanche has been estimated from height differences on both banks at a curve along the valley through which the avalanche flowed and from the travel-distance time relation.

Key words

debris avalanche