1:45 PM - 2:00 PM
[SVC35-01] A working hypothesis for source craters and sequence of the 1707 Hoei eruption of Fuji Volcano, Japan
Keywords:Fuji Volcano, 1707 Hoei eruption, source craters, Hoei mound, eruption sequence, working hypothesis
The 1707 Hoei eruption, one of the most voluminous and violent eruptions of Fuji Volcano, has been considered to have occurred from the NW-SE trending three craters (Hoei craters) on the southeastern flank of the volcano and to have made the bulge (Hoei mound) at the edge of the craters. The Akaiwa rock, located near the summit of the Hoei mound, has been thought to be an outcrop of older strata, which have unconformable relationship with overlying deposits.
On the basis of careful geomorphological and geological survey including SfM(Structure from Motion) technology with UAV photos, the strata exposed on the Akaiwa rock are revealed to be part of the proximal deposits of the Hoei eruption. Moreover, another NW-SE eruptive fissure is estimated to have opened between the Hoei mound and the Gotenniwa Higashi pyroclastic cone in the initial stage of the Hoei eruption and to have been buried by the subsequent eruptive deposits from the Hoei craters. The hypothesis of this fissure can resolve the problem thatlocation of a source crater of the basal pumice layer of the distal Hoei pyroclastic deposits is still unclear.
On the basis of careful geomorphological and geological survey including SfM(Structure from Motion) technology with UAV photos, the strata exposed on the Akaiwa rock are revealed to be part of the proximal deposits of the Hoei eruption. Moreover, another NW-SE eruptive fissure is estimated to have opened between the Hoei mound and the Gotenniwa Higashi pyroclastic cone in the initial stage of the Hoei eruption and to have been buried by the subsequent eruptive deposits from the Hoei craters. The hypothesis of this fissure can resolve the problem thatlocation of a source crater of the basal pumice layer of the distal Hoei pyroclastic deposits is still unclear.