8th Grade Science Chapter 8 Review: Volcanoes

Vocabulary practice flashcards covering volcanic structures, materials, classifications, and geothermal features from the Chapter 8 Review Sheet.

Eyjafjallajökull

The icecap in Iceland under which a volcano erupted in 2010.

Volcano

A depositional mountain landform built from solidified magma.

Igneous rock

The type of rock that composes volcanoes.

Extrusive volcano structure

A volcanic structure that forms on top of the Earth's crust.

Intrusive volcano structure

A volcanic structure that forms inside the Earth's crust.

Magma chamber

Large underground spaces filled with molten rock.

Vent

The opening in a volcano through which lava flows.

Crater

A bowl-shaped depression located at the top of a volcano.

Caldera

A huge crater-like depression formed at the top of a volcano.

Rhyolitic magma

A type of magma containing more than $63\%$ silica.

Andesitic magma

A type of magma containing $52\%\text{--}68\%$ silica.

Basaltic magma

A type of magma containing less than $52\%$ silica.

Lava flow speed

The movement speed of a typical lava flow, limited to as fast as a person could walk.

Pahoehoe

A type of lava that flows smoothly and cools with a ropey appearance.

'A'a

A type of lava that forms a splintered, sharply fractured, rough surface.

Pillow lava

A type of lava that hardens immediately underwater, forming rounded stacks.

Glowing avalanche

A rapid downhill flow consisting of hot solid particles suspended in water vapor or other gases.

Pyroclastic flow

Another name for a glowing avalanche of hot gases and solid volcanic fragments.

Lahar

A mudslide caused by volcanic activity.

Fumarole

A vent in or near a volcano from which gases escape.

Pyroclastic material

Solid volcanic materials ejected during an eruption, categorized into ash, cinder, bombs, and tephra.

Land volcano count

Approximately $1500$ active and dormant volcanoes are located on land.

Ring of Fire

The volcanic belt surrounding most of the Pacific Ocean, characterized by chains of volcanoes and frequent earthquakes.

Structural volcano classifications

The three types of volcanoes categorized by structure: shield volcanoes, cinder cones, and stratovolcanoes.

Activity volcano classifications

The three categories of volcanoes based on their eruption status: active, dormant, and extinct.

VEI

An abbreviation for the Volcanic Explosivity Index, which measures the explosiveness of eruptions.

Sill

An intrusive igneous formation that lies horizontally in a shelf-like formation parallel to existing rock strata.

Dike

An intrusive igneous body that always crosses through rock strata vertically or diagonally.

Batholith

A large pluton formed from deep underground igneous cooling.

Laccolith

An intrusive igneous formation featuring a domed upper surface, distinguishing it from a batholith.

Hot spring

A place where heated groundwater rises to the Earth's surface as a liquid.

Mud pot

A hot spring located in areas with thick deposits of fine volcanic ash and tephra.

Geyser

A hot spring that forcefully ejects water and steam from the ground at regular intervals.