12.1
Cards (22)
- Volcanic structures are formed due to the cooling of magma chambers.
- Volcanoes can be categorized based on their activity.
- Volcanoes can be categorized based on their type of eruption.
- Volcanoes can be categorized based on their location on the Earth's surface.
- Pyroclastic cones are small, steep mounds composed of tephra or volcanic fragments formed by explosive eruptions.
- A caldera is a large circular depression with steep walls and is at least 1-km wide.
- Volcanoes may also be classified based on mound structure, including lava domes, shield volcanoes, composite volcanoes, and pyroclastic cones.
- Shield volcanoes are broad gently-sloping mounds shaped like a soldier’s shield.
- Examples of calderas include Santorini Island, Mt. Taal Lake, and Yellowstone Park in USA.
- Parts of a volcano include the crater, magma chamber, conduits, dikes, sills, and the vents which could be a central vent, flank vent, or fissure.
- Composite volcanoes, also known as stratovolcanoes, are tall, steep, conical mountains.
- Lava domes are roughly circular mounds that form when viscous lava cannot flow too far due to the viscosity and cool into a mound.
- Magma chamber is an open space or an area of a highly fractured susbstrate where magma accumulates
- Conduit is the pipe or vent at the heart of a volcano where material wells up from beneath the surface.
- Crater is a circular depression around a volcanic vent where the lava, ash, and rock erupt out of a volcano.
- Volcanic flanks are the sides of a volcano which usually have fractures.
- Volcanic base is the bottom and foundation of the volcano.
- Sills are beds of rocks that form as a result of rock formation between layers of older materials.
- Dikes are rock sheets that can form from magma when they seep into cracks in rocks.
- Parasitic cone is the cone-shaped accumulation of volcanic material not part of the central vent of a volcano.
- Magma chamber, conduit/vent, crater, flank, and base are primary parts of volcano.
- Sills, dikes, parasitic cone, and caldera are secondary parts of volcano.