Geological Sites

Area AreaMotomachiMotomachi

Following the fissure eruption in the northern part of the caldera on 21 November 1986, a new fissure eruption started at 17:45 on the northwestern slope of the outer rim, which is the extension of the B crater sequence. Eleven craters were formed over a distance of about 1 km from southeast to northwest, and high columns of fire were raised. The craters were later named C1, C2, and so on in order from the southeast.

The outflow of a'a lava' from crater C6, the largest of the C crater sequence, which flowed along Nagasawa to within 200m of Motomachi. The town of Oshima issued an off-island evacuation for all islanders at 22:50 and a simultaneous evacuation was carried out during the night.

Lava Tree Mold

Cooling of a lava flow by water discharge

Location Information