Introduction to Volcanoes

Flashcards covering key concepts about volcanoes, their characteristics, types, and associated volcanic hazards.

What is a volcano?

A natural opening in the Earth's crust through which molten rock, gases, and ash are expelled.

What are the characteristics of shield volcanoes?

They have gentle slopes, broad shapes, and are formed by low-viscosity lava flows.

What defines a cinder cone volcano?

It is usually smaller, composed of loose volcanic fragments, has steep slopes, and a bowl-shaped crater.

What is a composite volcano?

Steep-sided, tall volcano built up by alternating layers of lava flows, ash, and debris, often with explosive eruptions.

What is a lahar?

A fast-moving flow of volcanic ash, rock, and water that poses significant hazards to communities.

What is ashfall?

Tephra or ash that falls over areas downwind of an erupting volcano, forming blankets of material.

Define pyroclastic flow.

A fast-moving avalanche of volcanic ash, rock fragments, and hot gases rushing down a volcano's slopes.

What is a ballistic projectile in a volcanic context?

Any object thrown by a volcano that travels under its own momentum, influenced by gravity and air resistance.

What are volcanic gases?

Gases released during eruptions, including water vapor, carbon dioxide, and sulfur dioxide, which can affect air quality.

What is a lava flow?

A stream or sheet of molten rock that pours from a volcanic vent and cools to form new rock.