13-1 Directed Reading

Name______Class______Date______

13-1 Directed Reading

1.What percentage of the Earth’s surface is covered with water?______

2.The global ocean is divided by the continents into ______main oceans.

How Did the oceans form?

______8.What happened to water vapor in the atmosphere when the early Earth cooled?

a.Water vapor dried up. b. Water vapor boiled.

c.Water vapor condensed. d. There was no gravity to pull water vapor to Earth.

9.How did condensed water vapor form the oceans?______

Characteristics of Ocean Water

______11.Which of the following statements about salt in the ocean is true?

a.It is sodium chloride. b. It is poisonous.

c.It is saltier than the salt we eat. d. It is less salty than the salt we eat.

______12.The measure of the amount of dissolved salts in a given amount of liquid is called

a.circulation. c. salinity.

b.sodium chloride. d. evaporation.

______13.Which waters tend to be saltier?

a.coastal waters in cool, humid environments b. river waters

c.coastal waters in hot, dry climates d. coastal waters near river outlets

______14.Which of the following happens when water evaporates?

a.Dissolved salts in the water also evaporate. b. Table salt is harvested.

c.Dissolved salts rise to the surface of the water. d. Dissolved salts in the water are left behind.

______15.Which of the following does NOT affect ocean salinity?

a.climate c. inflow of fresh water

b.sea animals d. water movement

16.How do minerals on land make oceans salty? ______

Match the correct definition with the correct term. Write the letter in the space provided.

______17.second, cooler layer of ocean water

______18.warm, top layer of ocean water

______19.bottom, coolest layer of ocean water

20. In the ______, temperature drops with greater depth faster than it does in the other two zones.

21.What two things affect surface-zone temperatures in most regions? ______

The ocean and the water cycle

______22.What three components make up Earth’s surface?

a.earth, wind, and fire b. mountains, rivers, and lakes

c.oceans, seas, and land d. water, land, and clouds (air)

______27.What is the most important function of the ocean?

a.It is home to thousands of animal species. b. It provides a safe place for recreational activities.

c.It absorbs and holds energy from sunlight. d. It has strong currents.

28.The ocean absorbs and releases thermal energy much more slowly than dry ______does.

29.Why are waters at the equator warmer than waters at higher latitudes? ______

30.How does the circulation of warm ocean water affect the climate of some coastal lands? ______

13-2 Directed Reading

Section: The Ocean Floor

Studying the ocean floor

_____1.What does sonar stand for?

a.sound and radar b. sound navigation and radio

c.sub-ocean navigation and ranging d.sound navigation and ranging

_____2.Sonar technology is based on the echo-ranging behavior of

a.sea lions. b. bats.

c.moths. d. seals.

7.How do scientists use sound to figure out the depth of the ocean? ______

Revealing the ocean floor

Match the correct description with the correct term. Write the letter in the space provided.

_____8.begins at the shoreline

_____9.slopes from the continental shelf to the ocean floor

_____10.forms the base of continental slope

_____11.is covered by mud

13. If the ocean were a giant swimming pool, the ______would be the shallow end.

14.Mountain chains formed by magma coming through rift zones are called______

15.Mountains on the ocean floor that can turn into volcanic islands are called______

16.When one oceanic plate is forced underneath another plate, a(n)______forms.

17.As mid-ocean ridges build up, a(n) ______forms between them in the rift zone.

1 14-1 Directed Reading

Section: Currents

1. Oceans contain streamlike movements of water known as ______.

2. What are three factors that influence currents?

surface currents

5.Horizontal movements of water that are caused by wind and occur on the ocean’s surface are called ______.

6.Compare the directions in which surface currents flow near the poles and near the equator. ______

7.Why do wind and surface currents appear to move in curved paths? ______

8.What is the apparent curved path of a moving object due to the Earth’s rotation called? ______

10.Where do cold-water and warm-water currents begin? ______

Deep currents

Match the correct description with the correct term. Write the letter in the space provided.

_____11.a streamlike movement of ocean water located far below the surface

_____12.the amount of matter in a given space, or volume

_____13.a measure of the amount of dissolved salts or solids in a liquid

_____14.a process which removes water but leaves solids behind

15.In polar regions, what happens to water molecules at the ocean’s surface? ______

16.Why does ocean water that is covered by ice increase in density? ______

17.Why does evaporation increase the density of ocean water? ______

18.Which is usually colder, a deep current or a surface current? ______

19.Which usually has greater salinity, a deep current or a surface current? ______

14-2 Directed Reading A

Section: Currents and Climate

Surface Currents and climate

_____1.Warmer climates in coastal areas that would otherwise be much cooler may be created by

a.cold-water currents. b. warm-water currents.

c.deep currents. d. breaking currents.

_____2.Where does the Gulf Stream get its warmth?

a.from the Tropics b. from the North Atlantic

c.from the British Isles d. from Newfoundland

_____3.The Gulf Stream carries warm water from the Tropics to

a.the South Atlantic Ocean. b. the South Pacific Ocean.

c.the North Atlantic Ocean. d. the North Pacific Ocean.

_____4.Currents that can keep coastal regions cooler than the inland climate year-round are

a.cold-water currents. b. warm-water currents.

c.deep currents. d. breaking currents.

_____5.The California Current carries cold water to Mexico from

a.the South Atlantic Ocean. b. the South Pacific Ocean.

c.the North Atlantic Ocean. d. the North Pacific Ocean.

_____6.Cold, nutrient-rich water from the deep ocean rises to the surface and replaces warm water in a process called

a.the Coriolis effect. b. upwelling.

c.El Niño. d. La Niña.

_____7.When upwelling takes place, cold water from the deep ocean

a.moves further out to sea. c. rises to the surface.

b.causes photosynthesis. d. gets replaced by warm water.

8.In what ocean do El Niño and La Niña form? ______

9.What is El Niño? ______

14-3 Directed Reading A
Section: Waves

anatomy of a wave

Match the correct description with the correct term. Write the letter in the space provided.

_____1.the highest part of a wave

_____2.the lowest part of a wave

_____3.the distance between two adjacent wave crests of water troughs

_____4.the vertical distance between the crest and trough of a wave

wave formation and movement

5.How do most waves form? ______

6.What happens to water when a wave of energy passes through it? ______

types of waves

Match the correct description with the correct term. Write the letter in the space provided.

_____11.waves that crest and then crash into the ocean floor

_____12.area where waves first begin to tumble downward, or break

_____13.the area between the breaker zone and the shore

_____14.a subsurface current that is near the shore and that pulls objects out to sea

_____15.a water current that travels near and parallel to the shoreline

_____17.long rolling waves that move steadily and at long distances across the ocean

_____18.a giant ocean wave that forms after a volcanic eruption, submarine earthquake, or landslide

_____19.a local rise in sea level near the shore, caused by strong winds from a hurricane or other storm

Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.

Holt Science and Technology1Exploring the Oceans