Word Network: 火口

A volcano is a mountain with an opening where lava, rocks, and gas come out from inside the Earth. In Japan, which has many active ones, it is a very common geographic feature and topic of discussion.

A hot spring.

Magma; molten rock beneath the Earth's surface.

A volcanic eruption where lava, gas, and ash are ejected from a volcano. It is used to describe both the geological event and the action of a volcano becoming active.