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
