Chapter 7

The geological feature "Great Salt Lake" in the state of Utah is an example of:

A paleo pluvial lake

A rule of thumb used by geoscientists is that a mesa has a top that is wider that its height, while a butte's top is narrower than its height. What causes the landform in this model to be termed a ''butte'' rather than a ''mesa''?

The landform in this model is free-standing, smaller than a mesa, and has a top that is narrower than it is high, so it is properly termed a ''butte.''

What does saltating mean?

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

Part B - Deserts of different latitudes

Subtropical desert Form due to persistent high atmospheric pressure. Location is due to global atmospheric patterns. Middle latitude desert Characterized primarily by minimal precipitation. Located far from major moisture sources like oceans. Uncommon desert features precipitation never occurs plants dont grow

How does the West Wind Drift contribute to the glaciation of Antarctica?

The West Wind Drift is a cold water current that circles Antarctica.

What will happen to the crust as a glacier grows?

The crust under the glacier will sink into the mantle.

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.

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 best describes the erosion skirts that encircle the buttes and mesas in arid landscapes?

The highly erodible shale and thin-bedded sandstone form gradual slopes that extend out from the base of the vertical cliffs formed from resistant, thick-bedded layers of sandstone or limestone.

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

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

Why does glacial subsidence NOT occur at the exact moment that a glacier forms?

The rate of subsidence is controlled by the rate at which mantle can flow.

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

The snow line would move downslope.

What shape is a glacial trough?

U-shaped

What would happen if the West Wind Drift stopped circling Antarctica?

Warmer water would flow down toward Antarctica, resulting in a warmer climate.

What is the name of the current that is blanked out in Figure 1?

West Wind Drift

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.

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.

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

a bajada

What is an end moraine?

a ridge of debris deposited at the end of a glacier

What is a playa commonly occupied by?

an ephemeral lake

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

an ephemeral stream

What is the largest type of glacier?

an ice sheet

How do glaciers move?

by the plastic flow of ice

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?

crevasses

Which way does ice flow in a glacier retreating uphill?

downslope

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

A high rate of Blank is often characteristic of a climate with high temperatures and low humidity.

evaporation

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?

horn

Where do glaciers form?

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

Part C - Rain shadows and deserts

left to right top wet, condensation, dry, desert bottom left to right windward, leeward

Most modern glaciers are __________.

retreating

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

rolling, sliding, bouncing, suspension

. Also known as steppe, climates are a type of dry climate that contain more water than arid climates.

semiarid

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

size

Thick Blank is not found in deserts because there are fewer plants than in more Blank climates.

soil humid

A desert has a drier climate than a Blank.

steppe

Which glacial feature indicates the maximum extent of a glacier?

terminal end 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

What is the zone of wastage?

the part of a glacier where snow melting exceeds snow accumulation

What is dust?

the particles carried in suspension by wind

What is isostasy?

the rising and sinking of Earth's crust relative to the mantle in response to the redistribution of mass on the surface

For how long will land rebound after a glacier melts?

thousands of years

Which glacier deposit are drumlins mainly composed of?

till

Part A

1. Interior drainagea discontinuous pattern of intermittent streams that do not flow to the oceantarget 1 of 8 2. Alluvial fana fan-shaped deposit formed when a stream's slope is abruptly reducedtarget 2 of 8 3. Bajadaan apron of sediment along a mountain front created by the coalescence of alluvial fanstarget 3 of 8 4. Playa lakecenter of basin where streams flow and briefly accumulate before evaporating or infiltrating bedrocktarget 4 of 8 5. Playaa dry, flat lake bedtarget 5 of 8 6. Salt flatencrusted salt layer left behind once water evaporatestarget 6 of 8 7. Inselberglarge bedrock knobs projecting above a sediment-filled basintarget 7 of 8 8. Basin and rangesmall mountain ranges separating circular downfolded structures

Antarctica has been continuously glaciated for the last __________ years.

30 million

What is the natural angle of repose for sand?

34 degrees

Why does the crust subside slightly on either side of a melting glacier?

Crust under the glacier rises as the ice melts. This allows mantle on either side of the glacier to move to areas under the glacier

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

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

Which of the following identifies the main erosion process responsible for the evolution of plateaus into buttes of the thicker sandstone, resulting in ''cliff retreat''?

Gravity-induced mass movements

Retreat of a glacier is indicative of:

Increasing wastage and/or decreasing accumulation

Why does the crust uplift slightly on either side of a growing glacier?

Mantle under the glacier is pushed aside by sinking crust. This mantle pushes up the crust on either side of the glacier.

How does an end moraine form?

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