Reevaluation of the Eruptive History of Fuji Volcano, Japan, Mainly Based on Historical Documents

Abstract

All available historical documents, which reeord abnormal phenomena relating (or possibly relating) to the activity of Fuji Volcano, Japan, were re-examined and classified aceording to the reliability of each document. Comparisons of the reliable descriptions with geologic evidence were executed and several new correlations between historical records and eruptive deposits are proposed. Volcanic activity of Fuji Volcano was in high-level from the 9th to I Ith century; in this period at least 7 reliable and 5 possible eruptions occurred. Although only 2 reliable and 1 possible eruption records exist from the 12th to the early 17th century, this low-level activity may be apparent because of lack of enough historical records. After the middle 17th century, enough historical records suggest that the activity is generally low except for the 1707 eruption, which is one of the most voluminous and explosive eruptions in the history of Fuji Volcano. At least thirteen large earthquakes (M 8 and possible M 8 class) have occurred near Fuji Volcano (in east Nankai and Sagami Troughs) since the 9th century. Eleven of these 13 earthquakes were accompanied with volcanic events (eruption, rumbling, or change in geothermal activity) of Fuji Volcano before and/or after each earthquake (in ±25 years).