The Solid Earth - Chapter 7: Nature of Volcanic Activity

Question 1

The primary factors to determine the nature of volcanic eruptions

Answer 1

magma’s composition, temperature, amount of dissolved gasses it contains

Question 2

How great something’s resistance to flow is

Answer 2

Viscosity

Question 3

As lava cools and begins to congeal, its mobility _____

Answer 3

decreases

Question 4

Magmas that produce basaltic rocks contain about ___ percent silica

Answer 4

50

Question 5

Rocks of granite composition contain over ___ percent silica

Answer 5

70

Question 6

A magma’s viscosity is directly related to its _____ content

Answer 6

Silica

Question 7

Which are more fluid - granatic lavas or basaltic lavas?

Answer 7

Basaltic Lavas

Question 8

Why is magma propelled by a volcanic vent?

True/False - energy is stored as pressure and is released/relieved when it is no longer at great depths

Answer 8

True

Question 9

Which are associated more with death - basaltic magmas or highly viscous magmas?

Answer 9

Highly viscous