5. During the most recent ice age, what percentage of Earth’s surface was covered by glaciers? (1 point)
90%
30%
75%
10%
6. In the desert, ephemeral streams ____. (1 point)
run continuously, although the amount of flow varies
run only after it rains
are actually dried stream beds that no longer carry water
carry water underground
7. Dry, flat lake beds located in the center of basins in arid areas are called ____. (1 point)
playas
arroyos
alluvial fans
desert pavements
8. A cone of debris deposited by running water at the mouth of a canyon in an arid area is known as a
____. (1 point)
delta
arroyo
ephemeral stream
alluvial fan
9. What force causes most of the erosion in desert areas? (1 point)
wind
gravity
running water
ice
10. The rust-colored tint of some desert landscapes is the result of ____. (1 point)
chemical weathering
mechanical weathering
flash flooding
the intense heat of the sun
11. What is the main type of weathering in deserts? (1 point)
chemical weathering
mechanical weathering
weathering by organic acids
weathering by water
12. The weathered debris in deserts consists mainly of ____. (1 point)
a thick soil layer
organic material from decaying plants
unchanged rock and mineral fragments
chemically altered rock fragments
13. Abrasion changes the desert surface by ____. (1 point)
creating blowouts
depositing loess across the landscape
cutting and polishing exposed rock surfaces
creating pinnacles and narrow pedestals in the rock
14. When wind creates a sand dune, the sheltered side of the dune ____. (1 point)
has no incline
has the same incline as the windward side
is steeper than the windward side
has a more gently sloping angle than the windward side
15. If the steep face of a sand dune is on the southeast side of the dune, then the prevailing wind in this area is from the ____. (1 point)
northeast
northwest
southeast
southwest
16. Dunes whose tips point into the wind are called ____. (1 point)
barchan dunes
longitudinal dunes
transverse dunes
parabolic dunes
17. The shape of star dunes is mostly due to ____. (1 point)
the amount of vegetation
variable wind directions
variable wind speeds
the amount of sand
18. What type of sand dune would most likely form if the sand supply is limited, the wind direction is constant, and vegetation is sparse? (1 point)
barchan dunes
longitudinal dunes
star dunes
transverse dunes
19. (1 point)
The lifting and removal of loose material by wind is called .
20. (1 point)
Deposits of windblown silt are called .
90%
30%
75%
10%
6. In the desert, ephemeral streams ____. (1 point)
run continuously, although the amount of flow varies
run only after it rains
are actually dried stream beds that no longer carry water
carry water underground
7. Dry, flat lake beds located in the center of basins in arid areas are called ____. (1 point)
playas
arroyos
alluvial fans
desert pavements
8. A cone of debris deposited by running water at the mouth of a canyon in an arid area is known as a
____. (1 point)delta
arroyo
ephemeral stream
alluvial fan
9. What force causes most of the erosion in desert areas? (1 point)
wind
gravity
running water
ice
10. The rust-colored tint of some desert landscapes is the result of ____. (1 point)
chemical weathering
mechanical weathering
flash flooding
the intense heat of the sun
11. What is the main type of weathering in deserts? (1 point)
chemical weathering
mechanical weathering
weathering by organic acids
weathering by water
12. The weathered debris in deserts consists mainly of ____. (1 point)
a thick soil layer
organic material from decaying plants
unchanged rock and mineral fragments
chemically altered rock fragments
13. Abrasion changes the desert surface by ____. (1 point)
creating blowouts
depositing loess across the landscape
cutting and polishing exposed rock surfaces
creating pinnacles and narrow pedestals in the rock
14. When wind creates a sand dune, the sheltered side of the dune ____. (1 point)
has no incline
has the same incline as the windward side
is steeper than the windward side
has a more gently sloping angle than the windward side
15. If the steep face of a sand dune is on the southeast side of the dune, then the prevailing wind in this area is from the ____. (1 point)
northeast
northwest
southeast
southwest
16. Dunes whose tips point into the wind are called ____. (1 point)
barchan dunes
longitudinal dunes
transverse dunes
parabolic dunes
17. The shape of star dunes is mostly due to ____. (1 point)
the amount of vegetation
variable wind directions
variable wind speeds
the amount of sand
18. What type of sand dune would most likely form if the sand supply is limited, the wind direction is constant, and vegetation is sparse? (1 point)
barchan dunes
longitudinal dunes
star dunes
transverse dunes
19. (1 point)
The lifting and removal of loose material by wind is called .
20. (1 point)
Deposits of windblown silt are called .