On Mt.Bandai

Before eruption in PWWW Mt.Bandai as viewed from the north

After eruption in PWWW Mt.Bandai as viewed from the north 

Outline

   Bandai volcano is located on the east side of Aizu basin and the north side

 of Lake Inawashiro. This volcano is PCWPX above sea level, this distribution

 area is about V east and west, PO north and south. This volcano belong

 to quaternary strato volcano. Around the top, there is caldera( hollow width PDT

 and extent PDT )hollow to the north and that is formed by eruption in 

PWWW. Despot of this collapse is found from northern slope to Ura-Bandai area 

widely. The present mountain is composed of first Bandai, second Bandai, third Bandai.


   Bandai volcanic history consists of three episodes.




EpisodeP

  When second Bandai stage, main volcano bodies, Mt.Akahani and Mt.Kushigamine,

 were formed and after that Okinajima collapse happened because of the mountain

 collapsed, and spread widely over west side around Okinajima(That area is Omote-Bandai).

 Right after, pyroclastic surge and rocky pyroclastic flow occurred.



EpisodeQ

  After a time since episodeP, Mt.Ohbandai that has comparatively steep slope was

 growing in caldera that was formed by the collapse. After that, the mountain collapsed

 again, and Suriage debris avalanche occurred in Omote-Bandai area.



EpisodeR

  After that, third Bandai volcano continued to grow. But this active is calming

 down, and after formed the mountain to some extent, Oyagawa debris flow was occurred

 by steam explosion that occurred around the top.

Reference to

A section including the largest debris avalanche deposits in the southwest foot of Bandai Volcano, northeast Japan -Okinajima and Suriage collapses-
Koji Mimura, Hidenori Endo, Yoichi Nakamura (1996)