Geological Sites

Area AreaSummit CalderaSummit Caldera

A steep cliff surrounds Mt. Mihara in front of us. This large depression is the Caldera. About 1700 years ago, large phreatic eruption occurred in summit area. Present shape of the caldera is thought to be formed by a cave-in during this eruption.

In the caldera, you can see lava from three different eruptions: the large An'ei eruption, the 1950-51 eruption, and the 1986 eruption.

The eastern edge of the caldera is not clear.

Layers of pyroclastic flow deposits can be seen in various parts of the island.

Location Information