Volcanic Landforms, Hot Springs and Geysers

After an eruption, the magma reservoir of a volcano may be partially emptied. Some volcanoes collapse into this chamber, forming a large depression on the surface called a caldera.

Volcanic necks are the remnants of a volcanic plug within a previously active volcano. The hardened magma is exposed by weathering and erosion. A dome mountain is magma that hardens below the crust and is uplifted.

Magma that exists very close to the Earth's surface can warm the groundwater. Hot springs and geysers are formed when this water emerges on the surface of the Earth.