Volcanic Hazards and Their Impact

This set of flashcards summarizes key vocabulary related to volcanic hazards, their characteristics, and associated geological terms.

Pyroclastic Flow

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

Lahar

A destructive mudflow composed of volcanic debris and water, often resulting from heavy rainfall or rapid snowmelt.

Seismicity

The occurrence of earthquakes in a particular area, often monitored to assess volcanic activity.

Gas Emissions

Release of gases such as water vapor, carbon dioxide, and sulfur dioxide from a volcano, which can indicate magma movement.

Mafic Lava

Low-viscosity lava that is typically hotter and flows more easily than other types; commonly associated with shield volcanoes.

Andesitic Lava

Intermediate lava with moderate viscosity that does not flow as far as mafic lava; often found in stratovolcanoes.

Rhyolitic Lava

High-viscosity lava that is thick and sticky, forming domes and not flowing easily; associated with explosive eruptions.

Volcanic Ash

Tiny fragments of rock and volcanic glass that are ejected during a volcanic eruption and can cause respiratory issues.

Volcanic Gas

Gases released during a volcanic eruption, such as sulfur dioxide and carbon dioxide, which can pose health risks.

Lava Flow

The movement of molten rock that erupts from a volcano, often causing destruction to infrastructure.

Geothermal Energy

Energy from the heat contained within the Earth's crust, often harnessed using geothermal power plants.

Mount St. Helens

A stratovolcano in Washington State known for its catastrophic eruption in May 1980.

Vesuvius

A stratovolcano in Italy famous for its eruption in AD 79 that buried the cities of Pompeii and Herculaneum.