Chapter 8

Question 1

Volcanoes are made of ______ rocks

Answer 1

igneous

Question 2

The term volcano originally came from the name for _______

Answer 2

a Roman God

Question 3

A volcano begins to form when magma fores its way to the surface and breaks through, forming a hole or

Answer 3

vent

Question 4

Where does pillow lava form?

Answer 4

underwater

Question 5

A mudslide caused by a volcano is called a ___

Answer 5

lahar

Question 6

List the size of particles from solid emission in order of smallest to largest

Answer 6

ash > cinder > bomb

Question 7

Which organisms are the base or first step of the food chain around black smokers deep within the ocean?

Answer 7

bacteria

Question 8

Which structure type is the most common for volcanoes?

Answer 8

stratovolcano

Question 9

How would a typical young-earth creation geologist’s view the formation of volcanoes?

Answer 9

Most volcanoes formed during or shortly after the Flood

Question 10

What are the three ways to describe the activity level of a volcano?

Answer 10

1. active
2. extinct
   3 dormant

Question 11

What is the name of the large volcano that we learned about in Washington?

Answer 11

Mt. Saint Helens

Question 12

The VEI of a volcano’s eruption is based on what?

Answer 12

1. The amount of tephra produced
2. the height of the eruption cloud
3. a descriptive estimate of the explosion

Question 13

Vertical is to dike as horizontal is to ____________

Answer 13

sill

Question 14

Batholiths and laccoliths are both types of _________

Answer 14

plutons

Question 15

A hydrothermal circuit is best seen in

Answer 15

the eruption of a geyser

Question 16

A spring that periodically ejects large quantities of hot water and steam is known as a ____________

Answer 16

geyser

Question 17

A _____ is a depositional mountain built up by molten rock that has risen to the earth’s surface through a vent.

Answer 17

volcano

Question 18

The depression found at the top of most volcanic cones is called a __________

Answer 18

crater

Question 19

A _________ is a vent in the ground through which hot gases escape.

Answer 19

fumarole

Question 20

Flood ________ are thick layers of igneous rock covering large portions of the earth. They are thought to have formed when huge quantities of magma were released through cracks in the earth’s crust.

Answer 20

basalts

Question 21

The internal energy of the earth, particularly evident in areas where hot springs are geysers exist, is sometimes harnessed for man’s use. This is called __________ energy.

Answer 21

geothermal

Question 22

Explain the relationship between the amount of silica that is found in a type of magma and its viscosity.

Answer 22

There are three different classifications of magma that are based on the percentage of silica they contain. Those with the lowest amount of silica are the least viscous. That is, they flow more easily than those higher in silica content.

Question 23

Why are so many volcanoes found in ares of tectonic activity?

Answer 23

Where plates are being subducted, great amounts of magma are being created. The mid-ocean rifts created by sea-floor spreading also allow magma to rise to the surface.

Question 24

Why is the term stratovolcano appropriate for the volcano structure type that it applies to?

Answer 24

These volcanoes intermittently release both lava and pyroclastic materials. The lava and tephra form layers or strata.

Question 25

What does the term geothermal gradient refer to?

Answer 25

The term geothermal gradient refers to the way the temperature within the earth increases continuously with its depth.

Question 26

Why do geysers and hot springs produce distinctive mineral deposits?

Answer 26

Hot groundwater is very effective at dissolving minerals in the rocks that it flows through. The hot water cools when it reaches the surface, causing the minerals to precipitate.