Bandai Type Eruption | John Seach


The eruption of Bandai volcano, Japan in 1888 showed the dangers of phreatic eruptions, which are capable of producing dangerous directed blasts.

The eruption was caused by hydrothermal pressurisation.

Features of the eruption.

1) No significant warning before the eruption.
2) The eruption was triggered by a magnitude 5 earthquake.
3) A pyroclastic density current accompanied the initial explosions.
4) The initial explosion only lasted a few minutes.
5) A plume reached a height of 5000 m, which collapsed producing warm rain, and lahars.
6) Ejected material was old rock fragments, with no juvenile glass.
7) The main pyroclastic density current extended from the summit for a distance of 6 km along the Biwazawa Valley on the southeast flank. Velocity was 100 m/s.