Volcanic Hazards and Society

Flashcards covering key vocabulary terms related to volcanic hazards and their societal implications.

Magma

Molten rock beneath the Earth's surface.

Lava

Magma that has reached the Earth's surface.

Volcanic Eruption

The release of magma, gases, and other materials from a volcano.

Pyroclastic Flow

A fast-moving current of hot gas and volcanic matter that flows down the slopes of a volcano.

Tephra

Loose fragments of volcanic rock ejected during an eruption.

Caldera

A large depression formed when a volcano erupts and collapses.

Geothermal Gradient

The rate of temperature change with depth in the Earth's crust.

Ring of Fire

A major area in the basin of the Pacific Ocean where many earthquakes and volcanic eruptions occur.

Volcanic Hazards

Potentially dangerous effects of volcanic activity.

VEI (Volcanic Explosivity Index)

A scale that measures the explosiveness of volcanic eruptions.

Stratovolcano

A volcano characterized by a conical shape and formed from multiple layers of lava and tephra.

Shield Volcano

A broad, gently sloping volcano built up by the flow of low-viscosity basalt lava.

Lahar

A destructive mudflow on the slopes of a volcano.

Volatile content

The amount of dissolved gases in magma that affects its explosiveness.

Decompression Melting

The process that occurs when there is a decrease in pressure that allows mantle rocks to melt.

Assimilation

The process where rising magma incorporates surrounding rock material, altering its composition.