Mt.Miharashinzan / Mt.Mihara Summit Pit Crater
| Area | Summit Caldera |
|---|
This crater changes in shape and size with each eruption. Lava filled the crater during the 1986 eruption, but it collapsed in an explosive eruption a year later, recreating a bowl-shaped crater. Since then, the crater wall has collapsed and now has a diameter of about 350 m and a depth of about 200 m.
At the top of the crater wall is the lava from the 1986 eruption. The vertical cracks formed when the lava cooled and solidified, make this look like a line of pillars.
The water is heated by underground magma, and white steam is rising from the bottom and surroundings of the crater.
Columnar joints of the 1986 eruption
Mt. Miharashinzan seen from the northwest