Chapter 6 Volcanoes 1 reading assignment

Tall, conical volcanoes, such as the one shown here, are associated with what type of plate boundary? Hot spot Spreading center Subduction zone Transform

Subduction zone

A volcano that has not erupted for a long time but is not extinct is referred to as being ____, which means sleeping.

dormant

True or false? All volcanism is associated with tectonic plate boundaries.

false

Why is volcanism not generally associated with transform faults? Transform faults are too far away from plate boundaries. Water is added to the mantle at transform faults, lowering its temperature. Mantle material is neither rising nor sinking at transform boundaries; the plates are simply sliding past each other. At transform faults, the crust is too thick to allow magma to reach the surface.

Mantle material is neither rising nor sinking at transform boundaries; the plates are simply sliding past each other.

The properties of magma vary in many ways that govern whether eruptions are peaceful or explosive. Which of these is not one of those? Plate tectonic setting Chemical composition Gas content Volume Ability to flow easily

Plate tectonic setting

Which of these are the two primary building blocks of knowledge for understanding volcanic eruptions? Earthquake locations Plate tectonics Volume of magma Properties of magma

Plate tectonics Properties of magma

Why does melting occur at spreading centers? Volcanic activity leads to higher temperatures in the crust. Temperature increases as mantle material descends. Pressure decreases as mantle material rises upward. Water is added to the mantle, lowering its melting temperature.

Pressure decreases as mantle material rises upward.

What drives melting at subduction zones? Decreased pressure due to upward convection of the mantle Increased temperature due to subduction of the slab into the mantle Release of water into the mantle, lowering its melting temperature The presence of a hot spot, which increases the temperature

Release of water into the mantle, lowering its melting temperature

Which plate tectonic settings are not associated with volcanic activity? Spreading centers Subduction zones Continental rifts Transform faults Continental collision zones

Transform faults Continental collision zones

If a volcano has a well-formed conical shape, we should classify it as _______. dormant extinct active

active

Volcanism not associated with plate boundaries typically occurs _______. within continental rifts at oceanic spreading centers over mantle hot spots at continental collision zones

over mantle hot spots

More than 70% of Earth's magma is erupted at _________. continental rift zones transform faults spreading centers continental hot spots subduction zones

spreading centers

Volcanoes located at ____ zones are explosive and dangerous. Listen to the complete question

subduction

The most explosive and dangerous volcanoes are generally found at _______. oceanic hot spots spreading centers subduction zones transform faults

subduction zones