Chapter 25.3 and 25.4

Question 1

What is the boundary that marks a density change between layers?

Answer 1

Discontinuity

Question 2

How can discontinuities be identified?

Answer 2

Seismic waves

Question 3

What are shadow zones?

Answer 3

Areas where no seismic waves are recorded

Question 4

What is another term/name for shadow zones?

Answer 4

“dead zone”

Question 5

Between what degrees do shadow zones fall?

Answer 5

105-140 degrees from the epicenter

Question 6

Is the outer core a solid or a liquid?

Answer 6

A liquid

Question 7

Is the inner core a solid or a liquid, and why?

Answer 7

Solid because of pressure

Question 8

What makes up the lithosphere?

Answer 8

The crust and uppermost mantle

Question 9

What is the asthenosphere?

Answer 9

A plastic like layer which Earth’s plates move.

Question 10

What elements make up the mantle?

Answer 10

Calcium, Aluminum, Iron, and Magnesium

Question 11

Which elements the core?

Answer 11

Iron and nickle

Question 12

The measure of a fluid’s resistance to flow.

Answer 12

Viscosity

Question 13

The chemical compound silicon dioxide which is a common ingredient in most magma.

Answer 13

Silica

Question 14

Small volcanoes that have heights in the hundreds of meters range and have short eruption cycles.

Answer 14

Cinder cone volcanoes

Question 15

Broad flat structures composed of layer upon layer of lava flows.

Answer 15

Shield volcanoes

Question 16

They are large and steep-sided, often thousands of meters high and tens of kilo meters across the base, and composed of layers of both lava and ash.

Answer 16

Composite volcanoes

Question 17

What is a volcano?

Answer 17

A feature that forms when magma reaches Earths surface and erupts as either lava or ash.

Question 18

Where do volcanic eruptions occur?

Answer 18

Where plates separate along a mid-ocean ridge or where plates collide along a subduction zone.

Question 19

What is the “ring of fire”?

Answer 19

Where most of Earth’s volcanoes are located around the Pacific Ocean.

Question 20

Why does volcanic activity along divergent boundaries go unnoticed?

Answer 20

It occurs under water along mid-ocean ridges

Question 21

What are hot spots?

Answer 21

Areas of volcanic activity where magma moves toward the surface in large, balloon like plumes

Question 22

What is the most common ingredient in magma?

Answer 22

Silica

Question 23

What is classified as pyroclastic material?

Answer 23

Any solid material that erupts from a volcano

Question 24

How are volcanoes classified?

Answer 24

According to their size, shape, and material that erupt.

Question 25

What are the three eruptive products from volcanoes?

Answer 25

1. Lava
2. Pyroclastic Material
3. Gases

Question 26

What is magma?

Answer 26

Molten,or liquid, rock stored inside earth.

Question 27

What are two specific location where volcanic activity occurs due to divergents?

Answer 27

1. East African Rift

2. Mid Atlantic Ridge

Question 28

Are hot spots stationary?

Answer 28

Yes

Question 29

If magma has a high viscosity will it contain more or less silica?

Answer 29

More

Question 30

What is pyroclastic material?

Answer 30

Any solid material that erupts from a volcano

Question 31

What is the smallest type of pyroclastic material?

Answer 31

Volcanic ash

Question 32

What is the largest type of pyroclastic material?

Answer 32

Volcanic blocks and bombs

Question 33

What are the types of gases that erupt from a volcano?

Answer 33

1. Water vapor
2. Carbon dioxide
3. Sulfur dioxide

Question 34

What are the three types of volcanoes?

Answer 34

1. Cinder-cone
2. Shield
3. Composite