Deck 10: Earthquakes and Earths Interior

Question 1

refers to the "bouncing" mode of sand transport in a windstorm or stream.

A) Ventifaction
B) Siltation
C) Deflation
D) Saltation

Answer 1

D

Question 2

What is the angle of repose for dry sand?

A) 67°
B) 10°
C) 6°
D) 34°

Answer 2

D

Question 3

Which one of the following will effectively limit further deflation in a desert area?

A) desert pavement
B) the water table
C) the repose level
D) sea level

Answer 3

A

Question 4

During a typical sandstorm, saltating sand grains reach a maximum height of about above the land surface.

A) 1 metre
B) 1 centimetre
C) 10 centimetres
D) 10 metres

Question 5

Assume that the slip face of a transverse dune slopes downhill toward the south. What is the direction of the prevailing wind?

A) east to west
B) south to north
C) north to south
D) west to east

Question 6

Assume that a longitudinal dune field has its dune crests oriented north- south, with a few dunes having hooked ends closed to the north, or branching, nearly parallel ridges opening to the south. What is the direction of the prevailing wind?

A) south to north
B) north to south
C) east to west
D) west to east

Question 7

Multiple, connected, crescent- shaped coastal dunes have tips pointing upwind, towards the beach.

A) barchan
B) transverse
C) longitudinal
D) parabolic

Question 8

Which one of the following concerning desert lands is false?

A) Wind erosion and deposition are important processes.
B) Running water has little effect on shaping the landscape.
C) Less than 30 percent is covered with dunes and drifting sand.
D) Most desert areas are characterized by descending wind patterns.

Question 9

Deposition of glacial silt from blowing winds near the ice front was responsible for .

A) blowout pavement
B) loess deposits
C) deflation ventifacts
D) star steppes

Question 10

Which of the following best describes the climatic factors that cause low latitude deserts like the Sahara in Africa?

A) Warm, humid air aloft is descending; surface winds blow away from the equator.
B) Warm, humid air is rising; surface winds are calm.
C) Cool, dry air at the surface is rising causing winds to blow away from the equator.
D) Cool, dry air aloft is descending; surface winds are blowing toward the equator.

Question 11

dunes have scalloped sand ridges at right angles to prevailing winds with crescent- shaped slip faces pointing downwind.

A) Barchanoid
B) Transverse
C) Parabolic
D) Star

Question 12

dunes are linear sand ridges at right angles to the prevailing wind direction in coastal areas, with a steady supply of sand.

A) Longitudinal
B) Parabolic
C) Barchan
D) Transverse

Question 13

All of the following are formed by abrasion except for a .

A) yardang
B) dune
C) ventifact
D) glacial striation

Question 14

Most dry lands lie between degrees north and south of the equator.

A) 40 and 50
B) 5 and 10
C) 20 and 30
D) 0 and 5

Question 15

What is the cause of the Patagonian desert?

A) rainshadow from onshore south Pacific westerlies and high elevations of the Andes
B) permanent high pressure and dry south polar easterlies
C) subtropical high from descending limb of the Tropic of Capricorn's Hadley cell
D) major river diversion of Rio de Plata for irrigation in northern Argentina

Question 16

Which of the following statements about wind transport is true?

A) Wind can transport boulders by saltation.
B) Wind cannot carry clay particles because they are too small.
C) Saltation knocks down cacti up to 5 metres high.
D) Dust from the Sahara Desert can be carried across the Atlantic Ocean.

Question 17

Assume that the central slip face of a parabolic dune slopes downhill toward the west. What is the direction of the prevailing wind?

A) east to west
B) west to east
C) north to south
D) south to north

Question 18

Which type of dune can be up to 90 metres tall and forms under variable wind directions?

A) transverse
B) barchan
C) star
D) parabolic

Question 19

Rainshadow deserts are common in the lee of major mountain ranges such as in .

A) the dry valleys of the Okanagan and farther south in eastern California and Nevada
B) north central Africa
C) Europe north of the Alps
D) vast, dry, steppe lands like the Great Plains and central America

Question 20

Which one of the following is the best measure of the wetness or dryness of a region?

A) percentage of precipitation that falls during the summer months
B) mean annual temperature
C) total annual precipitation
D) difference between annual precipitation and evaporation potential

Question 21

Which one of the following is determined by the angle of repose for dry sand?

A) a vertical cut bank in loess
B) inclination angle of a dune slip face
C) windward slope of a transverse dune
D) longitudinal dune gradient angle

Question 22

Stream channels in dry lands that only carry water in response to infrequent rainfall or snowmelt events are called .

A) rills
B) washboards
C) ephemeral
D) playas

Question 23

Which inland body of water in central Asia has shrunk by over 90% due to diversion of streams for irrigation?

A) Aral Sea
B) Black Sea
C) Red Sea
D) Baltic Sea

Question 24

Which Canadian dryland area receives the least precipitation (<50 mm/a) ?

A) central Yukon
B) Okanagan Valley, B.C.
C) SE Alberta and SW Saskatchewan
D) eastern Arctic especially Ellesmere Island, Nunavut

Question 25

Which one of the following statements is true?

A) Rainshadow deserts occur where air masses descend after first having risen to cross a mountain range.
B) Despite infrequent rainfalls, erosional and depositional features of running water are important in desert landscapes.
C) Desert landscapes are monotonous, relatively flat areas covered to various depths with sand.
D) Deserts and dry lands are concentrated in areas of ascending air masses and relatively low atmospheric pressures.

Question 26

How is desert pavement formed?

A) Blowing wind removes fine- size soil particles; coarser particles abrades to sand size.
B) Running water deposits gravel and sand over the finer- sized soil particles.
C) Intense chemical weathering removes the sand- and silt- sized particles, leaving coarse rock debris covering the land surface.
D) Deflation and sheet wash remove fine- sized materials leaving coarse, weathered, rock fragments concentrated at the surface.

Question 27

A is formed by abrasion of rocks by windblown sand.

A) desert pavement
B) ventifact
C) playa
D) pediment

Question 28

In a dry, fault- originated, basin and range area like the Okanagan Valley of BC and Washington, which environmental conditions are associated with steep mountain slopes and ephemeral streams?

A) Faulting ceased millions of years ago, resulting in moderate rainfall but very hot climate.
B) Faulting is probably still active, resulting in a steppe area with a rainy season.
C) Faulting is probably still active in the mountain rain shadow, producing a semi- arid climate.
D) Faulting ceased millions of years ago, resulting in an arid desert.

Question 29

dunes are linear sand ridges roughly parallel to the prevailing wind direction in areas of moderate sand supply.

A) Parabolic
B) Transverse
C) Longitudinal
D) Barchan

Question 30

A is a crescent- shaped dune whose tips point downwind.

A) parabolic
B) barchan
C) star
D) transverse

Question 31

How are sand grains transported by the wind?

A) by saltation as bed load in the first metre above the land surface
B) by deflation of abraded desert pavement
C) by being picked up in swirling dust devils and carried to distant blowouts
D) high in the moving air column as suspended load

Question 32

Assume that the central slip face of a barchan dune slopes downhill toward the east. What is the direction of the prevailing wind?

A) north to south
B) south to north
C) east to west
D) west to east

Question 33

A single, crescent- shaped dune is noted for slow rates of motion and tips pointing downwind.

A) longitudinal
B) parabolic
C) barchan
D) transverse

Question 34

Which type of dune resembles a transverse dune with scalloped edges pointing downwind?

A) barchanoid
B) hemorrhoid
C) parabolic
D) barchan

Question 35

A is closed depression in an arid region caused by .

A) sinkhole, wind abrasion
B) U- shaped valley, drying chinook winds
C) kettle hole, boiling desert springs
D) blowout, deflation

Question 36

Wind transported bed load along the desert floor is called _ .

A) bed shimmy
B) floor migration
C) desert crawl
D) surface creep

Question 37

Loess deposits in the central United States and Columbia Plateau .

A) accumulated from flooding of the Mississippi River
B) originated as silt sized particles in Pleistocene glacial outwash streams and freshly exposed till
C) blew in from the dry areas in the Great Plains and southwestern desert areas
D) were originally deposited as barchanoid dunes and later redeposited by glaciers

Question 38

are complexly shaped dunes in the Sahara or Arabian deserts, formed in response to different, seasonal, wind directions.

A) Star
B) Parabolic
C) Barchan
D) Transverse

Question 39

Which one of the following statements about sand dunes is correct?

A) The more gently sloping surface is the leeward slope of the dune.
B) In a sand dune, the more gently inclined strata lie parallel to the slip face.
C) Sand is blown up the slip face and rolls down the more gently sloping flank of the dune.
D) A dune migrates in the direction of inclination of the slip face.

Question 40

Which of the following drylands lies in the rainshadow caused by prevailing Pacific westerlies and the high peaks of the Coast Mountains and North Cascades?

A) Patagonian
B) Okanagan Valley
C) Sonoran
D) Atacama

Question 41

Which exerts the greatest amount of erosion and sculpting of landforms in deserts?

A) rainfall and running water
B) suspended silt load in perpetual dust storms of traversing winds
C) saltating bed load sand in great sandstorms of traversing winds
D) fast moving, descending, dense, cold dry air from the upper atmosphere

Question 42

have rainfall amounts and soil moisture contents between those of true deserts and humid lands.

A) Sabkhas
B) Steppes
C) Shelves
D) Tundras

Question 43

What is the term for a small depression formed by deflation of a desert floor?

Question 44

Which one of the following would probably not affect the size and depth of a blowout?

A) type and density of vegetation
B) a near surface water table
C) a rise in sea level
D) areas of desert pavement

Question 45

The tips of _ _ dunes point upwind and commonly result from persistent, onshore winds in certain coastal areas.

A) transverse
B) longitudinal
C) barchan
D) parabolic

Question 46

dunes are long, high, sand dunes parallel with the prevailing wind direction.

A) Longitudinal
B) Latitudinal
C) Subliminal
D) Transvestual

Question 47

What type of transport load does a stream carry that wind does not?

Question 48

All of the following statements concerning dry lands are true except for?

A) Precipitation totals are low; dew points are lower in the summer than winter.
B) Wind is the dominant agent of erosion and sediment transport.
C) Evaporation potential exceeds actual precipitation.
D) Storms are infrequent and rainfall amounts are highly variable.

Question 49

Where do the low- latitude deserts tend to occur?

Question 50

What is the cause of Canada's Arctic deserts like those on Cornwallis and Ellismere Islands?

A) permanent high pressure and dry north polar easterlies
B) subtropical high from the descending limb of the Tropic of Cancer's Hadley cell
C) a rainshadow from the Mackenzie Mountains in the Northwest Territories
D) overgrazing by musk oxen and melting of the Arctic ice cap

Question 51

Which one of the following statements concerning rock weathering is true?

A) Warm temperatures and low soil moisture contents both promote rapid rates of mechanical weathering.
B) Low temperatures and low soil moisture contents promote oxidation.
C) Low temperatures and high soil moisture contents accelerate chemical weathering but inhibit mechanical weathering.
D) Warm temperatures and high soil moisture contents accelerate chemical weathering.

Question 52

describes the complex, internal stratification or bedding in a sand dune.

Question 53

Which one of the following is a low-latitude desert characterized by high atmospheric pressures and descending air masses (not rain shadow deserts).

A) Atacama Desert in Chile, South America
B) desert valleys of the Great Basin, U.S.
C) Sahara Desert; northern Africa
D) Gobi Desert, China and Mongolia

Question 54

Desert and steppe lands cover about what percentage of Earth's land area?

A) 30%
B) 10%
C) 66%
D) 3%