Chapter 4

2012 U.S drought conditions

- About half the states in the continental United States experienced drier-than-normal conditions. - If 2012 is a guide, then the center of the country is more prone to dry conditions than most of the coastal areas.

Which of the following statements characterize the activity of glaciers and their impact on the landscape?

- Glaciers are capable of oversteepening slopes. Glacial activity can change the position of sea level relative to present conditions. - Glaciers are capable of moving large amounts of sediment. - Glaciers can impact the hydrologic cycle. - (All of the responses are valid.)

What observations would contradict the hypothesis that desert pavement forms through deflation? Choose all that apply.

- There are few or no pebbles found in the sediment beneath the desert pavement. - Windblown silt can accumulate and infiltrate through the pebbles.

How do glaciers move? Choose all that apply.

- by the plastic flow of ice - by ice mass sliding along the ground

What happens during the retreat of a glacier? Choose all that apply.

- the ice within the glacier flows forward - the zone of wastage decreases

The climate is warming

- the zone of wastage is growing - the elevation of the snow line increases

What shape is a glacial trough?

U-shaped

What is dust?

the particles carried in suspension by wind

Most of the erosion that took place during the "Dust Bowl" years of the 1930s in the Great Plains of North America was the result of which of the following processes?

wind

Human inpacts on drought

1. Increased in the rate of evaporation due to climate change can lead to drought. 2. Although there was low precipitation during the 1930s Dust Bowl, it was the farming methods, rather than low precipitation, that caused the extreme drought. 3. Changes in the land, such as deforestation through "slash and burn" practices and wildfires following overgrazing, cause the ground to dry and lead to drought. 4. Decreased rate of precipitation due to climate change can lead to drought. 5. Changes in the land surface, such as more asphalt, can increase heat absorption, which can increase the rate of evaporation.

According to Kazakh tradition, after a successful fox hunt what part of of the animal does the golden eagle get to eat?

According to Kazakh tradition, the golden eagle gets to eat the fox's lungs.

What does a successful hunt with his golden eagle mean for 16-year-old Berik?

After a successful hunt with his golden eagle, 16-year-old Berik is considered to be a Kazakh hunter and a man of his people.

During the last glacial maximum, the position of sea level occurred at what elevation relative to its position today?

At the last glacial maximum, sea level was about 100 meters (~300 feet) lower than it is today

What does saltating mean?

Sand grains are lifted by the wind, leap a short distance, and then fall back to the ground.

Which of the following statements is the best explanation for the occurrence of the Great Basin Desert in the western United States?

The Great Basin Desert exists because it is a rain shadow desert.

The Great Basin located in the western United States is what type of desert?

The Great Basin located in the western United States is what type of desert?

In the video, the narrator compares the grinding of surface rocks by the Nigardsbreen Glacier to what?

The advancing and retreating motion of the Nigardsbreen Glacier has been grinding down surface rocks like an enormous piece of sandpaper.

What gives the lake adjacent to the Nigardsbreen Glacier its deep blue color?

The deep blue color is the result of minerals found in dust that has washed into the lake.

Why is it difficult to reconstruct the glacial episodes of the Pleistocene Ice Age from the glacial record on land?

The glacial record on land is punctuated by many erosional gaps

What causes streams that emerge from glaciers to be milk-colored?

The presence of finely ground sediment called rock flour in the meltwater.

The climate is stable

The snowline remains at the same position

When desert pavement is produced in a desert, why do the larger particles accumulate on the surface?

The wind can move particles of only a very specific size and it takes away these small particles, concentrating the larger ones.

The climate is cooling

The zone of accumulation is growing

In the desert environment, how are ventifacts created?

Ventifacts are produced on the surface of a rock by the continued impact of very small particles carried by the wind.

Which of the following statements about deserts is true?

Water is the most significant agent of erosion in deserts.

What causes a crevasse to form?

When ice flows around a bend or over an obstacle, it is stretched and torn, causing large cracks to form.

You are working in a field area that you think at one time contained valley glaciers. What evidence would you look for to determine this?

You would look for rounded, U-shaped valleys.

When alluvial fans enlarge and coalesce in the desert environment in the Basin and Range region, what feature do they form?

a bajada

Which of the following accurately describes the Basin and Range region of the western United States?

a region with alternating mountains and basins that have been produced by normal faulting

A(n) __________ is a cone-shaped deposit of sediment that is deposited when a stream exits the mouth of a canyon.

alluvial fan

What is a playa commonly occupied by?

an ephemeral lake

Which of the following is a feature of a desert environment?

an ephemeral stream

Compared with the amount of ice that existed during the last glacial maximum, how much exists today?

approximately 1/3 as much

Where is the focal point of a glacier's growth?

cirque

What is the name used for cracks in the upper portion of a glacier?

crevassses

What is the name for an isolated boulder of unexpected rock type that has been transported by a glacier and stranded after the ice melts?

erratic

What is the name used for random boulders left behind by a glacier?

erratics

What type of rocks would you expect to find in a playa lake depositional environment?

evaporites and claystone

What is the name used for steep-sided inlets of the sea created when a glacial valley was flooded as sea level rose?

fjord

Which one of the following is an evaporite mineral?

gypsum

What is the name used for pyramid-like peaks sculpted by valley glaciers?

horns

What is the largest type of glacier?

ice sheet

An isolated, heavily eroded hill or mountain that rises abruptly from a plain is a(n) __________.

inselberg

Most modern glaciers are __________.

retreating

How do pieces of rock move under the influence of wind?

rolling, sliding, bouncing, suspension

Other than the landforms you learned about in the video, what is another landform present in the Basin and Range Province?

sand dunes

What property of a piece of material will most directly determine how it is carried by wind?

size

Which glacial feature indicates the maximum extent of a glacier?

terminal end moraine

Which of the following deserts is not considered a low-latitude or subtropical desert?

the Patagonian Desert

Which of the following can wind transport across large areas?

the suspended load

Which glacier deposit are drumlins mainly composed of?

till

What is the natural angle of repose for sand?

34 degrees

Why do the Kazakhs of the Altai Mountains use golden eagles to assist with hunting?

Because golden eagles have superior eyesight, the Kazakhs use them for hunting animals in the remote and barren Altai Mountains.

Areas of a glacier section are shown in the block diagram below. Characterize the style and velocity of ice movement at the indicated areas of this glacier. When answering this question, you should consider how pressure influences the brittle or plastic nature of ice, and how friction with bedrock affects ice movement.

Brittle ice is towards the top, ice moves slower close to the sides and faster the further away Plastic ice is towards the bottom and same thing. slower on the sides, and faster in the center

Which of the following statements characterizes ephemeral streams?

Ephemeral streams flow only at certain times of the year.

In order to carve out valleys, glaciers have to be strong enough to drag rocks and boulders down the mountainside, but what else has to happen for glaciers to create glacial valleys?

Glaciers have to be soft enough to move, and it is this movement that drags the rocks and boulders responsible for carving Earth's surface.

Which of the following provides the best explanation for the abundance of desert areas in the low latitudes?

High-pressure systems in these regions prevent the formation of clouds that could carry water.

Although both caused by climate change, temperature and precipitation changes are separate effects of a changing climate. Note that the focus here is precipitation.

Impacts due to lower precipitation : - decreased crop yields - increased risk of forest fire Impacts due to higher precipitation: - increased avalanche damage - increased potential for landslides Impacts due to other effects of climate change : - better farming at higher latitudes - increased risk of heat stroke

Traditionally, Kazakh hunters pair up with their golden eagles for how many years before they are set free?

Kazakh hunters pair up with their golden eagles for approximately seven years.

How do glaciers carve out valleys?

Moving glaciers engulf large boulders and rocks, which act as tools that scrape and chip away at solid rock.