Ocean Currents

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____	1.	Earth has both freshwater and salt water. About how much of Earth’s water is freshwater?

A.	  3%	
B.	15%	
C.	67%	
D.	97%	

____	2.	The pie chart below shows the gases that make up the air we breathe. 

About how many times more nitrogen is there in the air than oxygen? 

A.	about 2 times more	
B.	about 4 times more	
C.	about 5 times more	
D.	about 6 times more	

____	3.	The Florida Everglades is a large, warm wetland with many plants, animals, and microscopic organisms. Which part of the Earth system includes the water in the Everglades?

A.	geosphere	
B.	cryosphere	
C.	atmosphere	
D.	hydrosphere	

____	4.	Jessica is at the beach watching ocean waves. Which of these parts of the Earth system interacts with the hydrosphere to produce waves at the beach? 

A.	biosphere	
B.	geosphere	
C.	cryosphere	
D.	atmosphere	

____	5.	When trees die, they often fall on the ground and decompose. Which part of the Earth system includes dead and decomposed trees?

A.	biosphere	
B.	geosphere	
C.	atmosphere	
D.	hydrosphere	

____	6.	The graph below shows the composition of air.

Which two gases represent the smallest parts of the composition of air?

A.	oxygen and nitrogen	
B.	water vapor and oxygen	
C.	carbon dioxide and oxygen	
D.	water vapor and carbon dioxide	

____	7.	If Earth were a school building with three stories and a shingle roof, how thick would the atmosphere be? 

A.	as thick as the third story	
B.	as thick as the shingle roof	
C.	as thick as all three stories	
D.	as thick as the second and third stories	

____	8.	The pictures below represent various Earth spheres. Which picture would be considered part of the atmosphere?

A.		
B.		
C.		
D.		

____	9.	The Florida panther is one of the most endangered mammals on Earth. Where is the air that Florida panthers breathe?

A.	biosphere	
B.	geosphere	
C.	atmosphere	
D.	hydrosphere	

____	10.	The picture below shows the interaction of different spheres within the Earth system.

Which parts are interacting?

A.	hydrosphere and geosphere 	
B.	atmosphere and biosphere	
C.	cryosphere, hydrosphere, and biosphere	
D.	geosphere, cryosphere, and atmosphere	

____	11.	The picture below shows interactions between Earth systems.

How many systems are interacting?

A.	1	
B.	2	
C.	3	
D.	4	

____	12.	The picture below shows two of Earth’s spheres.

Which letter represents the mantle?

A.	Q	
B.	R	
C.	S	
D.	T	

____	13.	The picture below shows three of Earth’s spheres.

What two spheres are represented by the water and heron?

A.	biosphere and geosphere	
B.	atmosphere and biosphere	
C.	hydrosphere and biosphere	
D.	atmosphere and hydrosphere	

____	14.	Where is most of Earth’s water found?

A.	rivers	
B.	oceans	
C.	glaciers	
D.	groundwater	

____	15.	What three factors most directly affect surface currents in the oceans?

A.	dissolved solids, dissolved gases, energy	
B.	upwelling, convection, and the sun’s energy	
C.	deep currents, convection currents, and surface winds	
D.	surface winds, the Coriolis effect, and continental deflection	

____	16.	The following figure shows upwelling in the ocean.

Which of the following statements correctly describes the relationship between layers A and B?

A.	The water in layer B is warmer than the water in layer A, which is why the water in layer B rises.	
B.	The number of organisms in layer A will increase because nutrients from layer B rise during upwelling.	
C.	Layer A is rich in nutrients, which sink to layer B, increasing the density of water in layer B and causing it to rise.	
D.	The water in layer A is denser than the water in layer B, so the water in layer A sinks, pushing up water in layer B.	

____	17.	What is the source of the energy for ocean surface currents?

A.	the sun	
B.	nutrients	
C.	upwelling	
D.	convection	

____	18.	Carly draws a map of surface currents in the Atlantic Ocean. On her map, she includes the major wind belts for the same area. Her map is similar to the one shown.

If Carly wants to add wind belts for the part of the Atlantic just south of the equator, how should she draw the arrows?

A.	The arrows should curve upward to the left.	
B.	The arrows should curve upward to the right.	
C.	The arrows should curve downward to the left.	
D.	The arrows should curve downward to the right.	

____	19.	Donnie makes flash cards for the vocabulary in the chapter on ocean currents. For Coriolis effect, he writes the following definition:

the curving of the path of a moving object from a straight path

What important information did Donnie forget in his definition?

A.	due to wind	
B.	due to Earth’s rotation	
C.	due to the sun’s energy	
D.	due to continental deflection	

____	20.	Carlos and Chrissie look at the following map of the West Coast of the United States. An arrow on the map shows a surface current in the Pacific Ocean.

What should Carlos and Chrissie predict will happen to the current as it gets closer to the coast?

A.	The current will stop.	
B.	The current will change direction.	
C.	The path of the current will curve left.	
D.	The current will go in the opposite direction.	

____	21.	The following map shows the movement of heat throughout the global ocean. 

Based on the map, which of the following statements best summarizes the movement of heat through the world’s oceans?

A.	Warm water moves from the Atlantic Ocean to the Pacific Ocean.	
B.	Cold water moves away from the equator and picks up heat near the poles.	
C.	Warm water is found near the equator, and cold water is found near the poles.	
D.	Heat energy is transported from areas near the equator to areas near the poles.	

____	22.	What two factors determine the density of water in deep currents?

A.	salinity and temperature	
B.	the Coriolis effect and wind	
C.	upwelling and dissolved solids	
D.	continental deflection and convection	

____	23.	What causes a convection current to form?

A.	surface winds	
B.	the Coriolis effect	
C.	differences in density	
D.	continental deflection	

____	24.	Various solids, especially salts, dissolve in ocean water. Salts form ions when they dissolve in water. Vasily’s teacher gives him the following table, which lists the six most common ions found in ocean water. 

Ion	Concentration (mg/kg)	
chloride	19,350	
sodium	10,760	
magnesium	1,290	
sulfate	2710	
calcium	411	
potassium	399	

Based on the information in the table, which of the following salts could Vasily conclude is most commonly dissolved in ocean water?

A.	sodium sulfate	
B.	sodium chloride	
C.	calcium chloride	
D.	magnesium sulfate	

____	25.	Upwelling is important to ocean life. Which two nutrients carried by upwelling benefit phytoplankton the most?

A.	nitrogen and phosphorus	
B.	carbon dioxide and oxygen	
C.	sodium chloride and nitrogen	
D.	sodium chloride and carbon dioxide	

____	26.	Which of the following best shows the transfer of energy that produces movement of ocean water? 

A.	the sun ® wind ® surface current	
B.	the sun ® deep current ® upwelling	
C.	the sun ® wind ® convection current	
D.	the sun ® surface current ® upwelling	

____	27.	The following figure shows ocean currents.

What causes the change in direction in the Peru, California, and Canary Currents?

A.	the sun	
B.	surface winds	
C.	the Coriolis effect	
D.	continental deflection	

____	28.	Which of the following movements of ocean water has the greatest direct effect on the growth of producers?

A.	upwelling	
B.	deep current	
C.	surface current	
D.	convection current	

____	29.	Which of the following best describes the movement of heat energy in the global ocean?

A.	Heat energy is transported to the equator from the continents.	
B.	Heat energy in deep currents is transported to the ocean’s surface.	
C.	Heat energy in warm surface currents is transported to areas near Earth’s poles.	
D.	Heat energy is transported from areas of lower temperature to areas of higher temperature.	

____	30.	The atmosphere is the boundary between Earth and outer space. What is the atmosphere?
A.	the layer of gases that surrounds Earth	
B.	the layer above Earth that contains ozone	
C.	the layer above Earth in which weather happens	
D.	the layer above Earth that is responsible for gravity	

____	31.	The names and molecular structures of four atmospheric gases are shown in the following figures. Each gas constitutes a different percentage of Earth’s atmosphere. Which gas is most abundant in Earth’s atmosphere?
A.		
B.		
C.		
D.		

____	32.	The gases that make up Earth’s atmosphere are commonly referred to as air. Air consists of major gases and trace gases. What are the two most abundant gases in the atmosphere?
A.	nitrogen and oxygen	
B.	water vapor and argon	
C.	oxygen and carbon dioxide	
D.	nitrogen and carbon dioxide	

____	33.	The layer of gases that surrounds Earth is called the atmosphere. The atmosphere is tied to Earth by gravitation, so that it cannot disperse into space. Refer to the following circle graph.

The graph shows the relative abundance of gases in Earth’s atmosphere. Which gas(es) correspond(s) to label C in the figure?

A.	oxygen	
B.	nitrogen	
C.	argon and carbon dioxide	
D.	oxygen and carbon dioxide	

____	34.	At different places on Earth, depending on elevation, air pressure varies. Which of the following reflects the pressure at any point on Earth?
A.	carbon dioxide levels in the air	
B.	moisture (water vapor) in the air	
C.	the weight of the atmosphere above that elevation	
D.	the strength of Earth’s magnetic field at that elevation	

____	35.	Much of the ultraviolet radiation from the Sun is absorbed in the upper atmosphere. Which molecule is responsible for this?
A.	ozone	
B.	nitrogen	
C.	hydrogen	
D.	carbon dioxide	

____	36.	The atmosphere is divided into four layers. Which layer constitutes most of the total mass of the atmosphere?
A.	the mesosphere	
B.	the stratosphere	
C.	the thermosphere	
D.	the troposphere	

____	37.	An ozone molecule is shown in the following figure. It is made up of three oxygen atoms chemically bonded.

Which layer of  the atmosphere would contain the most of this molecule?

A.	the mesosphere	
B.	the stratosphere	
C.	the thermosphere	
D.	the troposphere	

____	38.	The atmosphere is divided into four layers, the mesosphere, troposphere, thermosphere, and stratosphere. Each layer has unique physical properties. Which of the following is true of the stratosphere?
A.	Weather happens in the stratosphere.	
B.	There are no winds in the stratosphere.	
C.	The stratosphere is below the troposphere.	
D.	The stratosphere is warmer at the top than at the bottom.	

____	39.	Earth’s atmosphere traps energy from the sun (greenhouse effect). What important fact results from this?
A.	Earth has weather.	
B.	Earth has gravity and magnetism.	
C.	Earth’s atmosphere has four layers.	
D.	Water can exist as a liquid on Earth.	

____	40.	The names and molecular structures of four atmospheric gases are shown in the following figures. Each gas constitutes a different percentage of Earth’s atmosphere. Which molecule can trap the greatest amount of heat  (greenhouse effect)?
A.		
B.		
C.		
D.		

____	41.	Cloudy nights are often warmer than clear nights. Why is this so?
A.	The clouds generate wind.	
B.	The water vapor traps heat energy during the daylight hours.	
C.	The clouds store and release heat from the inner Earth.	
D.	The clouds release heat generated by the friction of air molecules.	

____	42.	The circulation of air is caused by uneven heat distribution. Which of the following is primarily responsible for warming Earth?
A.		
B.		
C.		
D.		

____	43.	Different types of winds form in certain locations at different times of the day. Which breezes form during the day when land heats up faster than water?
A.	sea breezes	
B.	land breezes	
C.	valley breezes	
D.	mountain breezes	

____	44.	Different types of winds form in certain locations at different times of the day. Which breezes form at night when land cools faster than water?
A.	sea breezes	
B.	land breezes	
C.	valley breezes	
D.	mountain breezes	

____	45.	The Coriolis effect causes all freely moving objects in the air to curve instead of travel in a straight line. The Coriolis effect happens in both the Northern and Southern Hemispheres. How do objects curve in the Southern Hemisphere as a result of the Coriolis effect?
A.	to the left	
B.	to the right	
C.	to the north	
D.	to the south	

____	46.	In the eighteenth century, the trade winds played an important role in England’s merchant fleet crossing the Atlantic Ocean. This is how the trade winds got their name. In the tropics, in which direction do the trade winds drive equatorial ocean currents?
A.	eastward	
B.	northward	
C.	southward	
D.	westward	

____	47.	Meggie measures the wind speed every day for 7 weeks. She constructs the following line graph of the average daily wind speed.

What causes differences in wind speed?

A.	the orbit of Earth around the sun	
B.	the orbit of the moon around Earth	
C.	temperature differences caused by the gravity of Earth and the sun	
D.	density differences caused by uneven heating of Earth’s surface by the sun	

____	48.	Meggie measures the wind speed every day for 7 weeks. She constructs the following line graph of the average daily wind speed.

How many of the 7 weeks experience average wind speeds greater than 7.9 km/h?

A.	4 weeks	
B.	5 weeks	
C.	6 weeks	
D.	7 weeks	

____	49.	The following figure shows a valley between two mountains. The arrows indicate direction of air movement.

Which type of breeze is illustrated in the figure?

A.	a sea breeze	
B.	a land breeze	
C.	a valley breeze	
D.	a mountain breeze	

____	50.	Air rising and sinking in Earth’s atmosphere forms a pattern of smaller convection cells.

These convection cells create both high- and low-pressure belts. Where in the preceding diagram are the high-pressure belts located?

A.	A, B, C, D	
B.	A, C, E, G	
C.	D, E, F, G	
D.	B, C, D, E, F	

____	51.	Air rising and sinking in Earth’s atmosphere forms a pattern of smaller convection cells. 

These convection cells create both high- and low-pressure belts. Where in the preceding diagram are the low-pressure belts located?

A.	A, D, G	
B.	B, D, F	
C.	C, D, E	
D.	D, E, F, G	

____	52.	Rock and water absorb and release heat differently, causing localized air pressure differences. One result of this is land breezes. Which statement is true of land breezes?
A.	They originate in the day and blow toward the land.	
B.	They originate in the day and blow toward the water.	
C.	They originate in the evening and blow toward the land.	
D.	They originate in the evening and blow toward the water.	

____	53.	Air currents are sensitive to changes in temperature and pressure. In general, how does air move?
A.	from areas of high temperature to areas of low pressure	
B.	from areas of low temperature to areas of high pressure	
C.	from areas of higher pressure to areas of lower pressure	
D.	from areas of lower pressure to areas of higher pressure	

____	54.	Air circulates in Earth’s atmosphere. Which of the following is the fundamental cause of air circulation in Earth’s atmosphere?
A.	gravity	
B.	ocean currents	
C.	the ozone layer	
D.	temperature differences	

____	55.	The Coriolis effect is the curving of the path of a moving object. Which of the following does the Coriolis effect directly influence?
A.	only wind speed	
B.	only wind direction	
C.	both wind speed and wind direction	
D.	neither wind speed nor wind direction	

____	56.	Some characteristic types of wind result where global pressure belts meet. Which of the following is a narrow zone at the equator where surface winds are weak and variable?
A.	the doldrums	
B.	jet streams	
C.	local winds	
D.	the horse latitudes	

____	57.	Review the following figure.

Where on the diagram are the doldrums located?

A.	A	
B.	B	
C.	C	
D.	D	

____	58.	Which of these parts of the Earth system are interacting when Florida’s orange trees grow?

A.	biosphere, hydrosphere, and atmosphere	
B.	geosphere, cryosphere, and atmosphere	
C.	biosphere, hydrosphere, and cryosphere	
D.	cryosphere, atmosphere, and hydrosphere	

____	59.	Currents move in definite directions through the ocean. Many factors influence the direction and movement of these ocean currents. The following map shows surface currents in the ocean.

What factor causes the difference in movement of currents north and south of the equator?

A.	the sun’s energy	
B.	the Coriolis effect	
C.	the density of water	
D.	continental deflection	

____	60.	Air is in constant motion. As air rises higher into the atmosphere, what happens to the air pressure as the elevation increases?
A.	It increases.	
B.	It decreases.	
C.	It stays the same.	
D.	It increases at first, and then it decreases.	

____	61.	The following diagram shows the four layers of the atmosphere.

In which layer does most weather happen?

A.	layer 1	
B.	layer 2	
C.	layer 3	
D.	layer 4	

____	62.	Ozone is a gas found mostly in the upper atmosphere. What is the main benefit of ozone?
A.	Ozone protects Earth from loose space debris.	
B.	Ozone is responsible for rain, which provides water for Earth.	
C.	Ozone traps gravity so that objects on Earth do not float away.	
D.	Ozone filters out ultraviolet radiation from the sun and shields Earth from some of this harmful energy.	

____	63.	Look at the following image of a greenhouse. A greenhouse is a building where plants are cultivated. It traps some of the incoming solar radiation and, therefore, becomes warmer than the surrounding environment.

Which gas acts similarly to this greenhouse in its effect on the atmosphere?

A.	argon	
B.	carbon dioxide	
C.	nitrogen	
D.	oxygen	

____	64.	There are several major global wind systems on Earth. Which term describes tropical winds that blow from east to west?
A.	easterlies	
B.	jet streams	
C.	trade winds	
D.	westerlies	

____	65.	Rock and water absorb and release heat differently, causing localized air pressure differences. One result of this is sea breezes. Which statement is true of sea breezes?
A.	They originate in the day and blow toward the land.	
B.	They originate in the day and blow toward the water.	
C.	They originate in the evening and blow toward the land.	
D.	They originate in the evening and blow toward the water.