Chapter 18 Vocabulary

Question 1

Describes all the processes associated with the discharge of magma, hot water, and steam

Answer 1

Volcanism

Question 2

Unusually hot area in earth’s mantle where high-temperature plumes if magma rise toward the surface

Answer 2

Hot Spot

Question 3

Huge amounts of lava that erupt from fissures

Answer 3

Flood basalt

Question 4

A long crack in earth’s crust

Answer 4

Fissure

Question 5

A tube-like structure that allows lava to reach the surface

Answer 5

Conduit

Question 6

Opening in earth’s crust through which lava erupts and flows out onto the surface

Answer 6

Vent

Question 7

Bowl-shaped depression that forms around the central vent at the summit of a volcano

Answer 7

Crater

Question 8

Large crater that can form when the summit or side of a volcano collapses into the magma chamber during or after an eruption

Answer 8

Caldera

Question 9

Broad volcanoes with gently sloping slopes

Answer 9

Shield volcanoes

Question 10

Steed-sided, generally small volcano that is built by the accumulation of tephra around the vent

Answer 10

Cinder cones

Question 11

Generally cone-shaped with concave slopes

Answer 11

Composite Volcanoes

Question 12

Magma that flows onto earth’s surface

Answer 12

Lava

Question 13

Describes magma or igneous rock that is rich in magnesium and iron that is generally dark in color

Answer 13

Mafic

Question 14

Describes magma or igneous rock that is rich in feldspar and silica and that is generally light in color

Answer 14

Felsic

Question 15

Describes a material’s resistance to flow

Answer 15

Viscosity

Question 16

Rock fragments, classified by size, that are thrown into the air during a volcanic eruption and fall to the ground

Answer 16

Tephra

Question 17

Swift-moving, potentially deadly clouds of gas, ash, and other volcanic material produced by a volcanic eruption

Answer 17

Pyroclastic flow