Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology 43 Plate Tectonics

The Layered EarthComplete this worksheet after you finish reading the section “Inside the Earth.”

Use the following terms to label the diagram below. Then, use the terms to fill inthe blanks in the sentences that follow. Terms may be used more than once.

crust outer core mantleinner core mesosphere asthenospheretectonic plate

WHAT AM I?

I am part of the lithosphere, but I move around on top of the asthenosphere. I am

a(n) .

WHERE ARE WE?

We journeyed to the center of the Earth, and when we got there we discoveredthat the core has two parts! One part is liquid and is called the

. The other part is dense and solid and is called the

.

Name Class Date

ReinforcementSkills Worksheet

Lithosphere

1.

2.

3.

4.

5.

6.

7.

18. Answers will vary. At a subductionzone, the lithosphere is denser than itis at a mid-ocean ridge. Convectioncauses oceanic lithosphere to moveaway from the mid ocean ridge.Oceanic lithosphere is also higher at amid-ocean ridge, so oceanic litho-sphere moves down toward the sub-duction zone because of gravity.

19. Answers will vary. The amount ofcrust formed is roughly equal to theamount of crust destroyed globally. Ifthis were not true, the Earth wouldeither be expanding or shrinking.

20. At the time they formed, the foldedmountains must have been on theedge of a tectonic plate. New materialwas later added to the tectonic plate,causing the folded mountains to belocated closer to the center of the continent.

21. 50 km 22. 150km�250km�2,550km�2,950km23. between 50 km and 150 km 24. 150 km � 250 km � 2,550 km � 2,200

km � 5,150 km

Reinforcement

THE LAYERED EARTH1. Crust2. Mantle3. Outer core4. Inner core5. Crust6. Asthenosphere7. Mesosphere

A MOVING JIGSAW PUZZLE1. divergent2. transform3. convergent

Critical Thinking1. Answers will vary. Sample answer:

Athena may have a liquid centersurrounded by a solid, flexible outerlayer.

2. Answers will vary. Sample answer:Athena’s top layer must be made of amaterial less rigid and more flexiblethan the rock of Earth’s crust.Otherwise, it would probably crackdue to the stress.

3. The color of the sky and the smell ofthe air probably do not indicateanything about the planet’s innerstructure.

4. Answers will vary. Sample answer: If there are events like earthquakes onthe planet, they could useseismographs to measure the speedand angles of any seismic wavesproduced. They also might try to drillinto the planet’s surface in order tosee the layers.

5. Answers will vary. Sample answer: They should discuss their findingswith other scientists in the field first.They should then make sure that noother hypotheses can be supported bytheir data.

Section QuizzesSECTION: INSIDE THE EARTH1. C 5. C2. A 6. E3. D 7. A4. B 8. F

SECTION: RESTLESS CONTINENTS1. D 5. A2. A 6. D3. B 7. C4. B 8. E

SECTION: THE THEORY OF PLATETECTONICS1. A 5. E2. C 6. C3. D 7. B4. A 8. F

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Science and Technology 100 Plate Tectonics

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