Volcanism and Volcanoes

Flashcards covering vocabulary related to volcanism and volcanoes, including definitions of key terms learned in the lecture.

Volcanism

Processes leading to the extrusion of magma, gases, and pyroclastic materials onto the surface and into the atmosphere.

Gabbro

A black plutonic rock that contains mineral crystals.

Active Volcanoes

Volcanoes that are currently erupting or show signs of erupting.

Dormant Volcanoes

Volcanoes that have not erupted recently but may do so in the future.

Extinct Volcanoes

Volcanoes that are no longer active and show no evidence of erupting again.

Volcanic Gases

Gases released during an eruption, mainly water vapor, carbon dioxide, and sulfur dioxide.

Lava Flows

Streams of molten rock that flow from a volcano during an eruption.

Pahoehoe

A type of lava flow that has a smooth, ropy surface.

Aa

A type of lava flow that is rough and jagged.

Pyroclastic Rock

Volcanic rock that forms from the explosive eruption of magma.

Tephra

Solid fragments of volcanic material ejected during an eruption.

Volcanic Explosivity Index (VEI)

A scale used to measure the explosiveness of volcanic eruptions.

Caldera

A large depression formed when a volcano's magma chamber empties and collapses.

Cinder Cone

A small, steep-sided volcano formed from the accumulation of volcanic ash and cinders.

Shield Volcano

A broad, gently sloping volcano built from fluid lava flows.

Stratovolcano

A volcano composed of layers of lava flows and pyroclastic materials.

Fissure Eruptions

Eruptions that occur along fractures in the Earth's crust, leading to widespread lava flow.

Pyroclastic Flow

A fast-moving current of hot gas and volcanic debris (ash, rock) that flows down the side of a volcano during certain eruptions.