Major types include strata, volcanoes which often appear as tall, steep mountains, shield volcanoes, which are flatter and dome shaped calderas, which are large depressions in the ground and mid ocean ridges, which are underwater chains of volcanic mountains, no matter their shape or size, all volcanoes emit gas and molten rock.
主要類型包括地層,火山通常表現為高大陡峭的山峰,盾形火山是比較平坦的圓頂形火山口,是地面上的大凹陷,中洋脊是水下的火山鏈,無論其形狀或大小,所有火山都會排放氣體和熔岩。