User:Guanlongwucaii/Bayonnaise Rocks
| Bayonnaise Rocks | |
|---|---|
 Steam pours from the blocky summit of Myōjin-shō during a submarine eruption at Bayonnaise Rocks volcano in 1952. | |
| Highest point | |
| Elevation | Below sea level |
| Coordinates | 31°53′N 139°55′E / 31.88°N 139.92°E |
| Geography | |
 | |
| Location | Izu Islands, Japan |
| Geology | |
| Mountain type | Caldera |
| Last eruption | 1970 |
The Bayonnaise Rocks represent part of the barely exposed rim of a largely submarine 8-9 km wide caldera. The caldera has a history of Holocene eruptive activity beginning from a submarine eruption in 1869.
Most historical eruptions have occurred from Myojin-sho, a large post-caldera lava dome constructed on the NE rim of the caldera. Deposits from submarine pyroclastic flows associated with growth of the dacitic lava dome mantle the conical dome and extend into the NE part of the caldera and down its outer slopes. An explosive submarine eruption from Myojin-sho in 1952 destroyed a Japanese research vessel, killing all 31 on board. Submarine eruptions have also been observed from other points on the caldera rim and outside of the caldera.[1]
The most recent confirmed eruption was in 1970, but unverified eruptions have been reported as late as 1988.[2]