Volcano key terms

Question 1

Hotspot

Answer 1

Volcanic locales thought to be fed by underlying mantle that is anomalously hot compared with surrounding mantle

Question 2

Volcanic Explosivity Index

Answer 2

A scale used to measure the explosivity of volcanoes

Question 3

Magma plume

Answer 3

Areas of hot, upwelling mantle

Question 4

Lahar

Answer 4

Mudflows composed of pyroclastic material and water that flows down from a volcano, usually along a river valley

Question 5

Lava

Answer 5

Hot molten/semi-fluid rock erupted from a volcano or fissure, or the subsequent solid rock after it has cooled

Question 6

Pyroclastic flows

Answer 6

A high density mass of gasses, hot ash, and larger material that flows rapidly down the side of a volcano

Question 7

Nuee ardente

Answer 7

An incandecent cloud of gas, ash, and lava fragments ejected from a volcano, typically as part of a pyroclastic flow

Question 8

Tephra

Answer 8

Any type of rock fragment that is forcibly ejected from a volcano during an eruption

Question 9

Volcanic bombs

Answer 9

Rocks that are more than 5mm in diameter thay are thrown into the air by a volcanic eruption

Question 10

Volcanic gasses

Answer 10

Gasses that are released from a volcano, including carbon dioxide, carbon monoxide, hydrogen sulphide, sulphur dioxide, and chlorine

Question 11

Tsunami

Answer 11

Giant sea waves that are generated by shallow focus underwater earthquakes, volcanic eruptions, underwater debris slides, and landslides into the sea

Question 12

Acid rain

Answer 12

The gasses released from a volcano combine with atmospheric moisture, resulting in acid rain

Question 13

Viscosity

Answer 13

The resulting density of lava determined by the magnitude of its internal friction