Chapter 6 Test

Question 1

Earthquake

Answer 1

Vibrations in the ground that result from movement along faults or breaks in earth’s lithosphere

Question 2

Fault

Answer 2

A break in earth’s lithosphere

Question 3

3 types of faults

Answer 3

Normal fault
Strike slip fault
Reverse fault

Question 4

Normal fault

Answer 4

Forms when forces pull rocks along a divergent plate boundarie; block above fault moves down

Question 5

Strike slip fault

Answer 5

Two blocks of rock slide horizontally past each other in opposite directions

Question 6

Reverse

Answer 6

Forces pushes two blocks of rock together with the rock above the fault moving up

Question 7

Focus

Answer 7

Point beneath earth’s surface where rock under stress breaks to cause an earthquake

Question 8

Epicenter

Answer 8

Point on the surface directly above the focus

Question 9

Seismic waves

Answer 9

Waves that carry energy of an earthquake away from the focus

Question 10

What are the 3 kinds of seismic waves?

Answer 10

Primary waves
Secondary waves
Surface waves

Question 11

Primary waves (p-waves)

Answer 11

Compression waves that travel through solids and liquids

Question 12

Secondary waves (S-waves)

Answer 12

Only travels through solids and temporarily changes shape

Question 13

Surface waves

Answer 13

Moves slower than P and S waves, but can produce severe ground movement with a wavelike motion

Question 14

Seismometers

Answer 14

Devices that measure and record ground motion and helps determine the distance seismic waves travel (Lag time)

Question 15

How do you locate an epicenter?

Answer 15

By triangulating the data from at least 3 seismometers

1. Find the lag time
2. Find the distance to the epicenter
3. Use map scale to mark radius on compass then draw circle around each

Question 16

Volcano

Answer 16

Weak spot in earth’s crust where molten material comes to the surface

Question 17

Magma

Answer 17

Molten mixture of rock forming substances, gasses, and water from the mantle.

Question 18

Lava

Answer 18

When magma reaches the surface, it’s called lava

Question 19

Ring of fire

Answer 19

One major belt formed by many volcanoes that rim the Pacific Ocean

Question 20

What is a string of islands created by volcanoes near boundaries where 2 oceanic plates collide and one skins beneath the other?

Answer 20

Island arc

Question 21

What is an area where material from deep within the mantle rises then melts, forming magma?

Answer 21

Hot Spot

Question 22

Geologists classify eruptions as either:

Answer 22

Quiet or explosive

Question 23

Quiet eruption

Answer 23

Magma has low silica content, flows easily and erupts quietly with gasses gently bubbling out and lava oosing gently producing both pahoehoe and aa

Question 24

Explosive eruption

Answer 24

Magma high in silica content, with trapped gasses building up pressure inside until they explode with incredible force creating a pyroclastic flow

Question 25

Pahoehoe

Answer 25

Hot, fast moving lava

Question 26

Aa

Answer 26

Cooler, slow moving lava

Question 27

Pyroclastic flow

Answer 27

An eruption that hurls ash, cinders, and magma bombs

Question 28

Active volcano could explode anytime,
Dormant volcano not active but may become active
Extinct volcanoes unlikely to erupt again

Answer 28

Lightning forms in volcanoes bc all the ash rubs together causing friction eventually making lightning

Question 29

Landforms from lava and ash

Answer 29

1. Shield volcano
2. Cinder come volcano
3. Composite volcano
4. Lava plateaus
5. Caldera

Question 30

Landforms from magma

Answer 30

Volcanic necks
Dikes
Sill
Batholiths
Dome mountain

Question 31

What is geothermal activity?

Answer 31

Occurs when magma, a few kilometers beneath earth’s surface, heats underground water and forms

Question 32

Hot springs!

Answer 32

Formed when underground water is heated by a nearby body of magma or hot rock and eventually rises to the surface to collect in an all natural pool

Question 33

Geyser

Answer 33

Fountain of water that erupts from the ground when buildup of pressure is released