The Work Of Wind And Deserts Ch 15

Front 1

desert

Back 1

area that recieves <25cm of rain a year
-high evaporation
-low vegetation

Front 2

wind patterns

Back 2

hot air rises at equator, cold air sinks at poles

Front 3

wind patterns

Back 3

hot air rises at equator, cold air sinks at poles

Front 4

coroilis effect

Back 4

veers wind off course and creates 3 wind belts:
trade winds, westerlies, and polar easterlies

Front 5

locations of deserts

Back 5

-30, 90 latitude N&S because air is sinking and low, and pressure is high
-60 latitude because air is rising and the pressure is low - storms
-along the equator doldrums

Front 6

wind patterns

Back 6

-30, 90 latitude N&S because air is sinking and low, and pressure is high
-60 latitude because air is rising and the pressure is low - storms
-along the equator doldrums

Front 7

locations of deserts

Back 7

-at belts with high pressure - near 30 lat. N and S (sahara, arabian ect)
-rainshadow deserts

Front 8

rainshadow deserts

Back 8

on leeward side of mtns
- patagonian, great basin

Front 9

desert temp

Back 9

hot! daytime average around 32-38 degrees celsius 90-100 f or hotter.
often cold a night

Front 10

desert vegetation

Back 10

sparse plant cover
amazing diversity with plants that adapt by forming hard waxy leaves with wide shallow root systems

Front 11

desert weathering

Back 11

mechanical dominates because the daily temp fluctuates, frost wedging
-desert varnish

Front 12

desert varnish

Back 12

coating of manganese oxide on rock surfaces
-ancient people used this to make petroglyphs

Front 13

desert soil

Back 13

thin and patchy - cryptobiotic crust

Front 14

cryptobiotic crust

Back 14

in the great basin - bound together by cyanobcteria mosses and lichens.
-provides a stable environment for plant growth and prevents erosion.
-easily destroyed

Front 15

desert streams/groundwater

Back 15

mostly losing streams (intermittent), deep water table.

Front 16

desert wind

Back 16

can also be an effective erosional agent
it transports sediment that is unconsolidated and, silt, and dust sized particles

Front 17

abrasion

Back 17

sandblasting effect within a meter of surface
-modified existing features (form bizarre shapes)

Front 18

ventifacts

Back 18

stones polished and faceted by wind

Front 19

deflation

Back 19

removal of lose sediment by wind
can form desert pavement

Front 20

desert pavement

Back 20

mosaic of close fitting rocks from deflation

Front 21

dunes

Back 21

mounds or ridges of wind deposited sand
- sand moves up windward side by saltation
- sand collapses down leeward (angle of repose)
- cause it to migrate
- results in asymmetric profile

Front 22

loess

Back 22

deposits of wind blown silt and clay derived from deserts, p ice age glacial outwash stream in floodplains in semi arid regions.

makes midwest and E WA fertile!!

Front 23

playa

Back 23

dry lake bad found in deserts
-mudcracks and salt deposits (forms when the lakes dry up)

Front 24

alluvial fans

Back 24

cone shaped mass of sand and gravel
-where stream flows from mtns to lowlands
-common in desert esp in basin and range

Front 25

mesas

Back 25

width is greater than height

Front 26

buttes

Back 26

width equals heights

Front 27

pinnacles

Back 27

height is greater than width