Volcanoes and Their Types

Study Notes

Volcanoes are geological features.
They result from the accumulation and release of magma or molten rock from beneath the Earth's surface.

Cinder Cone:
- These are small, steep mounds composed of tephra (volcanic fragments).
- They are formed by explosive eruptions.
- Example: Parícutin in Mexico
Composite Cone (Stratovolcano):
- These are large, steep volcanoes.
- They are formed by alternating layers of lava, ash, and volcanic rocks.
- They form from successive eruptions.
- Example: Mount Fuji, Mount Mayon
Shield Volcano:
- They form when low-viscosity basaltic lava flows freely from a vent.
- They stack upon each other.
- They have a wide base and a gentle slope, like a warrior shield.
- Example: Mount Kilauea in Hawaii
Lava Dome:
- Formed when viscous lava cannot flow far, it cools in a mound shape.
- Example: Mount Cleveland Lava Dome (USA)

Crater/Summit:
- Funnel-shaped depression at the top. Formed by explosive eruptions.
Vent:
- Opening through which lava and gases erupt.
Conduit/Pipe:
- Tube connecting the magma chamber to the surface.
Flank:
- The side of the volcano
Base:
- Bottom of the volcano
Magma Chamber:
- Underground reservoir of molten rock.
Ash Cloud:
- Ejected material.

Caldera:
- A volcanic crater formed when part of the crater wall collapses after an eruption.
Volcanic Flank:
- The side of a volcano usually containing some fractures.
Volcanic Base:
- Bottom and foundation of the volcano. Could be where the volcano meets the surface water (ocean bed).
Magma/Lava
- Magma is molten rock beneath the Earth's surface, it transforms into lava when it erupts through the Earth's surface.