Planet Earth Exam 2 multiple choice

All of Earth's oceans are connected and water flows from one to another.

True

An echo sounder determines water depth by measuring the time it takes a sound signal to bounce off the seafloor and travel back to the instrument.

True

An ocean wave moves along the sea surface, but the water in the wave travels in circular paths.

True

As you move downward from the surface of the ocean, the movement of water becomes less affected by wind and more affected by the Coriolis effect.

True

Currently, Earth has only two ice sheets.

True

Glaciers form U-shaped valleys.

True

In recent years, increasing atmospheric carbon dioxide has caused seawater to become more acidic.

True

Much of the northern Great Plains is covered with ground moraines, loess, or outwash.

True

Oceans are commonly warmer than adjacent land in the winter and cooler in the summer.

True

Pressure from the weight of overlying ice favors melting at the base.

True

Sea levels has risen and fallen repeatedly in the geological past, and coastlines have emerged and submerged throughout Earth's history.

True

Seismic reflection profilers work by emitting a high-energy signal that penetrates and reflects from layers of sediment and rock below the seafloor.

True

Some coastlines are rising isostatically because the lithosphere was depressed by thick ice sheets during the Pleistocene glaciation that have since melted away.

True

The Atlantic Ocean opened as the supercontinent Pangea rifted apart about 250 million years ago.

True

The Mid-Oceanic Ridge system is Earth's largest mountain chain.

True

The Snowball Earth hypothesis suggests that during the late-Precambrian, ice completely covered all of the continents, and the world's oceans froze over.

True

The salinity of the oceans has been relatively constant throughout much of geological time because salt has been removed form seawater at roughly the same rate at which it has been added.

True

A glacier that forms in mountainous terrain and covers an area of less than 50,000 square kilometers is a(n) _____ glacier. a. alpine b. continental c. ice sheet d. erratic

a. alpine

What term describes the gradual movement of sediment (usually sand) along a beach parallel to the shoreline, when waves strike the beach obliquely but return to the sea directly? a. beach drift b. Ekman transport c. wave push d. downshore current

a. beach drift

Samples of sediment can be collected from the seafloor using _____. a. coring devices b. echo sounders c. seismic profilers d. remote sensing

a. coring devices

Oceanic crust is ____ than continental crust and therefore ____ isostatically. a. denser; sinks b. denser; rises c. lighter; sinks d. lighter; rises

a. denser; sinks

The Mid-Oceanic Ridge rises high above the surrounding sea floor because new lithosphere is forming at the ridge axis is ____ and of relatively ___ density. a. hot; low b. hot; high c. cool; high d. cool; low

a. hot; low

Magnetometers can be used to ____. a. study the past behavior of seafloor spreading along mid-ocean ridges b. measure the depth of water beneath a ship c. collect samples of sediment and rock from the seafloor d. detect earthquakes

a. study the past behavior of seafloor spreading along mid-ocean ridges

Most of the water that fills Earth's oceans came from ___. a. the outer regions of the Solar System b. the collision with a Mars-sized object that formed the Moon c. volcanoes d. a gigantic flood

a. the outer regions of the Solar System

The layer of ocean water in which temperature drops rapidly with depth is called the ____. a. thermocline b. halocline c. pycnocline d. tempicline

a. thermocline

Due to the Coriolis effect, currents in the Northern Hemisphere ____. a. are deflected to the left b. are deflected to the right c. flow in straight lines d. end up flowing to the south

b. are deflected to the right

Rift valleys can be found at ___ plate boundaries a. convergent b. divergent c. transform d. passive

b. divergent

An emergent coastline forms where sea level ___ or coastal land ___. a. falls; sinks b. falls; rises c. rises; sinks d. rises; rises

b. falls; rises

The two most common ions dissolved in seawater are ____. a. magnesium and carbonate b. sodium and chloride c. calcium and sulfate d. potassium and gold

b. sodium and chloride

During an interval of 24 hours and 53 minutes, most coastlines experience ___ high tide (s) and ___ low tide (s). a. one; one b. two; two c. three; two d. four; four

b. two; two

Glacier-carved valleys are typically ___. a. V-shaped b. very narrow c. U-shaped d. similar in appearance to valleys carved by steep mountain streams

c. U-shaped

Deep-sea currents are driven by ____. a. wind b. the Coriolis effect c. differences in water density d. the Gulf Stream

c. differences in water density

Ocean water density depends on ____. a. temperature only b. salinity only c. temperature and salinity d. water color

c. temperature and salinity

Cycles identified by Milutin Milankovic' are caused by ___. a. changes in Earth's tides b. increased sunspot activity c. variations in Earth's orbit and spin axis d. increased volcanic activity

c. variations in Earth's orbit and spin axis

The ice sheets of Greenland and Antarctica contain ____ percent of the world's ice. a. 25 b. 75 c. 50 d. 99

d. 99

During a glaciation _____. a. all of the continental land is covered by ice, but the oceans remain ice-free b. ice covers all of Earth's land and water c. the high latitudes are ice covered, but there are no glaciers exist near the equator d. alpine glaciers descend into lowlands, and continental glaciers spread over the high-latitude continents

d. alpine glaciers descend into lowlands, and continental glaciers spread over the high-latitude continents

When two oceanic plates converge, the sinking plate pulls the sea floor down to create ____. a. a black smoker b. a rift valley c. accreted terranes d. an oceanic trench

d. an oceanic trench

What is a large piece of space debris, such as an asteroid or comet, that crashes into a planet? a. nebula b. volatile c. geoid d. bolide

d. bolide

A relatively warm, ice-free, time between glaciations is called a(n) ____. a. precessional cycle b. pluvial period c. Milankovitch cycle d. interglacial period

d. interglacial period

A spring tide is a _____ tide that occurs when the Sun, Moon, and Earth are ____. a. small; 90° out of alignment b. large; 90° out of alignment c. small; aligned d. large; aligned

d. large; aligned

The waterfalls of Yosemite Valley cascade from hanging valleys.

true

Precession relates to the shape of Earth's orbit around the Sun.

False

Rates of glacial movement depend entirely on air temperature.

False

There is no volcanic activity along subduction zones.

False

Trenches along subduction zones form because the two places are spreading apart.

False

Alpine glaciers are found on every continent on Earth.

False

Although many of Earth's alpine glaciers have been rapidly shrinking in recent years, the Antarctic Ice Sheet has remained stable, losing no ice mass.

False

During the formation of the solar system, the solar wind pulled volatile compounds toward the inner planets.

False

Granite is more dense than basalt.

False

Oceanic crust is thicker than continental crust.

False