ch13 flashcards

Question 1

desert

Answer 1

A region with very low precipitation, resulting in sparse vegetation and a landscape shaped primarily by wind and occasional flash floods

Question 2

rainshadow

Answer 2

A dry region on the leeward side of a mountain range, created as moist air rises, cools, and loses moisture on the windward side, leaving little rainfall beyond the mountains

Question 3

subtropical deserts

Answer 3

Deserts located around 20°–30° north and south latitudes, formed under high-pressure zones where air is descending, warm, and dry

Question 4

internal drainage

Answer 4

A hydrologic condition in desert basins where streams do not reach the ocean; water instead collects in playas or is lost through evaporation

Question 5

basin and range

Answer 5

A landscape of alternating basins (low-lying areas) and ranges (uplifted mountains), common in deserts, often with internal drainage

Question 6

alluvial fan

Answer 6

A fan-shaped deposit of sediment formed where a stream flows out of a mountain range and onto a flatter plain, losing velocity and dropping its load

Question 7

bajada

Answer 7

A broad, continuous apron of alluvial material formed from the merging of multiple alluvial fans along a mountain front

Question 8

playa

Answer 8

A flat, dried-up lake bed found in desert basins, often covered with fine-grained sediments and evaporite minerals

Question 9

Inselberg

Answer 9

An isolated, steep-sided residual hill or mountain rising abruptly from a flat desert plain, formed by prolonged erosion of surrounding material

Question 10

pediment

Answer 10

A gently sloping rock surface at the base of a desert mountain range, formed by erosion and often partially covered by alluvium

Question 11

plateaus

Answer 11

Broad, elevated flat areas of land, typically capped by resistant rock layers, formed by uplift and differential erosion in desert landscapes

Question 12

mesa

Answer 12

A flat-topped hill with steep sides, smaller than a plateau but larger than a butte, created by erosion isolating a portion of a plateau

Question 13

butte

Answer 13

A narrow, isolated hill with a flat top and steep sides, smaller than a mesa, formed by further erosion of a mesa or plateau

Question 14

spire

Answer 14

A tall, slender pinnacle of rock left standing after more resistant rock remains while surrounding material erodes away

Question 15

wind erosion

Answer 15

The removal, transportation, and abrasion of surface materials by the wind, prominent in deserts due to lack of vegetation and moisture

Question 16

abrasion (wind)

Answer 16

The grinding and wearing down of surfaces by particles carried by the wind, resulting in polished, smoothed, or pitted rock surfaces

Question 17

deflation

Answer 17

The process by which wind removes loose, fine-grained particles from the surface, lowering the land and leaving coarser materials behind

Question 18

blowout

Answer 18

A shallow depression formed by wind erosion removing loose sediment, common in sand-rich areas with sparse vegetation

Question 19

ventifact

Answer 19

A rock that has been shaped, polished, or pitted by wind-driven sand, often with flat or faceted surfaces

Question 20

loess

Answer 20

A fine, windblown silt deposit, composed mostly of quartz, that can form thick, fertile soils once stabilized

Question 21

sand dune

Answer 21

A hill or ridge of sand deposited by wind, taking on various shapes depending on wind direction, sediment supply, and vegetation

Question 22

barchan dune

Answer 22

A crescent-shaped sand dune with horns pointing downwind, formed where sand supply is limited and wind blows consistently from one direction

Question 23

transverse dune

Answer 23

Long ridges of sand oriented perpendicular to the prevailing wind direction, formed where sand supply is abundant

Question 24

longitudinal dune

Answer 24

Long, narrow dunes that form parallel to the prevailing wind direction, often where wind varies slightly and sand supply is moderate

Question 25

star (irregular) dune

Answer 25

A sand dune with multiple arms radiating from a central peak, formed where winds blow from several directions, creating a complex shape

Question 26

coastal (parabolic) dune

Answer 26

A U-shaped dune formed along coastlines, with arms stabilized by vegetation and the open end of the “U” pointing upwind

Question 27

fault

Answer 27

A fracture in rock along which there is movement; in deserts, faults can influence the formation of basins, ranges, and drainage patterns

Question 28

flash flood

Answer 28

A sudden, short-lived torrent of water in a desert environment caused by intense rainfall over a short period, rapidly eroding and transporting sediment

Question 29

parabolic dune (coastal dune)

Answer 29

Another term for coastal dune, these form along shores where vegetation partially stabilizes some sand, directing the dune's arms into a U-shape

Question 30

playa lake

Answer 30

A temporary lake in a desert basin that appears after rainfall and evaporates quickly, often leaving behind minerals and salts

Question 31

slip face

Answer 31

The steep, downwind side of a sand dune where sand grains tumble down after being carried over the crest by the wind

Question 32

ventiface (alternative spelling: ventifact)

Answer 32

A rock surface abraded by wind-blown sand, showing evidence of wind erosion

Question 33

outwash

Answer 33

Sediment (typically sand and gravel) deposited by meltwater streams flowing from a glacier, forming features like outwash plains and valley trains