Chapter 18

Which of the following distances represents one wavelength of the wave set drawn below?

A to C represents a wavelength.

Which of the following describes the movement of air in a hurricane in the Northern Hemisphere?

Air moves up from the surface in a counterclockwise direction.

Which two regions currently contain the world's last remaining ice sheets?

Antarctica and Greenland

What glacial feature is circled in Figure 1?

Arete

Which part of a glacier is responsible for abrasion and plucking?

Basal sliding zone

Which beach stabilization technique requires dumping many truckloads of sand on a beach to build it up?

Beach Nourishment

A ________ is a shoreline stabilization feature that protects shorelines from the pounding of waves by creating an area of quiet water behind it.

Breakwater

Which of the following will not occur as the result of longshore currents?

Fracturing and abrasion of rock

Under what conditions will the front of a glacier remain stationary?

Glacial fronts remain stationary when melting and snow accumulation are equal.

Which glacial erosion feature will likely contain a waterfall today?

Hanging valley

Where do hurricanes that hit the East Coast of the United States form? In which direction do they travel?

Hurricanes form in the Atlantic Ocean north of the equator and move in a northwest direction.

Which of the following statements about hurricanes is true?

Hurricanes lose energy when moving over land.

Explain why post A has moved farther than posts B and C.

Ice in the center of a glacier has the least friction with the surrounding bedrock and can flow faster.

Which of the following is not part of the Milankovitch Cycle?

Isostacy

________ form when waves that approach the beach at an angle and produce a net current direction that is parallel to the shore, resulting in beach drift.

Longshore currents

Which of the following depositional features is produced by longshore transport?

Spit

Which moraine marks the furthest extent of glacial ice?

Terminal moraine

A set of waves are moving from east to west. Assuming the boat is in deep water, which of the following would describe the motion of a boat during the passage of these waves?

The boat would move up and down in the water.

The snowline and zones of accumulation and wastage are labeled in the figure below. For each of the scenarios described, use the descriptions of a glacier to determine how the climate is changing.

The climate is warming The zone of wastage is growing The elevation of the snowline increases The climate is cooling The zone of accumulation is growing The climate is stable The snowline remains at the same position

How would you expect the front of a glacier to move if it undergoes a period of net accumulation, followed by net wastage, and finally a period of net accumulation?

The glacier's front would move forward, backward, and then forward again.

Which of the following is a characteristic of glacial till?

The particles are often scratched and polished.

How would a snow line on a glacier move as a glacial front is advancing?

The snow line would move downslope.

Look again at the Gigapan image, and note the main features in this landscape. Observe what type of glacier this is given the surrounding landscape. Compare the sizes and shapes of the various glacial zones, as well as the associated landscape features. Then, review the statements below and indicate which are correct for this particular glacier. Select all that apply.

This glacier appears to be retreating. It is easy to find till in this image.

What shape will glacial troughs generally display?

U

What is the best way to describe the shape of a glacial valley?

U-shaped

What is the wave base?

Water depth equal to 1/2 the distance between successive waves

How shallow must the ocean floor be for waves to start to "feel bottom" for a wave set with a wavelength of 20 feet?

Waves will "feel bottom" when the ocean floor is 10 feet below the surface.

Will plucking occur if a glacier is NOT advancing?

Yes, because glacial ice is still moving inside the glacier even if the glacier's front is not advancing.

What is an end moraine?

a ridge of debris deposited at the end of a glacier

Based on the diagram below, select which arrow best represents the direction of the longshore current.

arrow moving to the right. Parallel to the shore line

Which way would sediment move if NO beach drift existed?

at an angle to shore

Which type of glacial movement is circled in Figure 1?

basal sliding

Which way does ice flow in a glacier retreating uphill?

downhill

What glacial landform is visible in Figure 1?

drumlin

Which orbital effect describes how the shape of Earth's orbit around the Sun will change over time?

eccentricity

Which of the following scenarios will have the greatest chance of triggering an ice age?

eccentricity, obliquity, and precession overlapping to provide the least amount of solar radiation

Valley glaciers are capable of moving independently of the topography.

false

What glacial feature is circled in Figure 2?

horn

Which of the following is not an example of alpine glaciation?

ice sheet

Where do glaciers form?

in places where more snow falls in the winter than melts away in the summer

Which type of glacial movement will be responsible for the greatest amount of glacial flow?

internal flow

What is the major source of moisture needed to generate glaciers?

oceans

What term describes the bending of waves?

refraction

________ is an elevation point above which snow remains throughout the year.

snowline

What feature is responsible for creating eskers?

streams that flowed below, in, or on the glacier

Which landform marks the furthest extent of an advancing glacier?

terminal moraine

What is the snowline?

the elevation above which snow persists throughout the year

Which is the best definition of glacial snow line?

the line dividing zones of accumulation and melting of ice at the surface of a glacier

As a wave passes under a floating object, _____.

the object will move vertically a distance equal to that of the wave height

What is the zone of wastage?

the part of a glacier where snow melting exceeds snow accumulation

A large wave generated by an earthquake off the coast of Chile can travel across the Pacific Ocean to reach the shores of Alaska.

true

Any hard stabilization method of protecting beaches from erosion is ultimately a form of temporary protection.

true

Coastal areas undergo some of the most rapid and dynamic change due to their constant contact with the water.

true

Due to the crashing of waves and the backwash of water from shore, beaches can be thought of as areas where material is in transit.

true

The only continental ice sheets left on Earth today are in Greenland and Antarctica.

true

What effect will an increased angle of tilt have on the Earth's climate?

warmer summers and colder winters

What is the longshore current?

water forced by waves to move along the shore

If the wavelength of a set of waves is 20 feet long, how deep is the wave base?

10 feet below the surface

What percentage of the Earth is currently covered by glacial ice?

10%

When was the last glacial maximum in North America?

18,000 years ago

When was the last time North America had major ice sheets?

18,000 years ago

How many years does one complete cycle of precession take?

26,000 years

If the distance from one wave crest to the next is 10 ft., what will the depth to the wave base be?

5 ft.

What is the critical latitude for incoming solar radiation, which could affect the formation of ice sheets?

65° N

In the long term, what do beach drift and longshore current do?

Move sediment parallel to the shoreline

Which of the following describes the general pattern of movement of sand on a shoreline?

Net sand movement is parallel to the shore.

__________ are defined as a chain of glacial lakes where each lake flows into the next.

Pater noster lakes

How does an end moraine form?

Pieces of rock are transported to the front of a glacier as ice within the glacier moves.

________ is a strong current formed by backwash concentrated into small channels and flows rapidly away from the beach.

Rip Currents

Which of the following is a coastal feature that is not as likely to be found along a passive continental margin?

Sea Cave

Which of the following statements describe what happens to sediment when a longshore current meets a jetty?

Sediment is eroded on the down-current side of the jetty because water is starved of sediment in this location. Sediment is deposited on the up-current side of the jetty because water moves slower in this location.

During which month are hurricanes most likely to occur on the east coast of the United States?

September