GE 112 Quiz 5

the grinding and shaping of rock surfaces by the sand blasting action of particles captured in the air is termed

abrasion

which of the following is not considered a cause of desertification

afforestation

cone-shaped deposits of sediment often found at mouth of canyons in arid and semiarid climates are called

alluvial fans

ephemeral channels that form in drylands climates in response to infrequent precipitation events are known as

arroyos

the oral sea, once one of the four largest lakes in the world, has steadily decreased since the 1960s on account of

diversion of incoming rivers for irrigation

an extensive area of sand and sand dunes is known as an

erg desert, or sand sea

the term eolian refers to

erosion, transportations, and deposition by the wind

for purposes of discussing eolian processes, the wind acts like a

fluid

the loess deposits in Europe and north America are thought to be derived mainly from

glacial and periglacial sources

dust storms, such as one from Arizona in 2013, are caused b downbursts associated with thunderstorms. such storms are termed

haboobs

the basin and range province in the western United States is an example of a ________ landscape

horst and graben

the ability of the wind to move materials

is small compared to other transporting agents, such as water and ice

which side of a dune typically has a slope angle equal to that of the angle of repose for sand

leeward

relative to dune movement and form, a dunes slipcase forms on which side

leeward side

windblown dust that accumulates into homogenous deposits is known as

loess

________ dunes form parallel to the prevailing wind, often extending for hundreds of kilometers in length

longitudinal

alluvial fans are formed as flowing water ________ as it leaves a constricted channel

loses velocity

________ are flat-topped landforms with steep slopes resulting from differential weathering

mesas

the coarsest materials, such as gravel, of an alluvial fan are found

near the mouth of the canyon

arid and semiarid climates cover about ________ of earths surface

one-third

in vegetation dune landscapes, ________ dunes form with their tips pointing upwind

parabolic

a large region identifiable by several topographic or geological traits is known as a

physiographic province

a _______ is a dry bed of an ephemeral lake a dryland region

playa

which of the following is not a general shape upon which scientists classify dunes

rectilinear

the smallest features shaped by individual saluting grains are

ripples

al alcove in sandstone, such as that in the cliff house at mese verde, is indicative of which weathering process

salt-crystal growth

the transport of small sand particles (0.07-0.20 mm) along the ground in a bouncing and skipping action is known as

saltation

which of the following terms is not a correct reference to a desert pavement

sand seas

factors that influence dry climates include all the following except

seasonal influence of the ITCZ

________ dunes are the largest in size and have multiple slip faces produced by winds from varying directions

star

the sliding and rolling along the ground of particles large 0.5 mm is known as

surface creep

desert pavement refers to

surfaces of concentrated pebbles and gravels

large depressions formed as a result of

tectonic forces combined with deflation

which of the following is correct regarding loess deposits

they are formed of fine-grained clays, silts and fine

the term used to describe rocks that are pitted, fluted, or polished from eolian erosion is

ventifacts

the leading cause of decline in Lake uremia is

water withdrawal

the sediment accumulation hypothesis of desert pavement formation states

wind delivers fine particles that settle and wash downward as cycles of swelling and shrinking cause gravels to migrate upward

the deflation hypothesis of desert pavement formation states

wind removes fine particles leaving large pebbles, gravels, and rocks, which become consolidated

elongated, streamlined ridges aligned parallel to the most effective wind direction are called

yardangs

active dunes cover approximately ________ of earths deserts

10%

saltation accounts for about ________ of sediment transport by wind

80%

drylands rugged terrain of sloped dissected by rills and gullies are known as

badlands

a ________ forms when individual alluvial fans coalesce

bajada

________ dunes form with their tips pointing downwind, usually in areas with limited sand supply and little to no vegetation

barchan

a depression created by deflation is known as a

blowout

which of the following areas is at highest (very high) risk of desertification

central canada

the vast loess deposits in china are thought to be derived mainly from

deeply entrenched river channels

the removal and lifting of individual loose particles by the wind is termed

deflation

dune migration on the Navajo nation in the us southwest is an example of

desertification

the general term for the land degradation in arid and semiarid regions characterized by expansions of deserts is

desertification