Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
|
Insolation |
amount of solar energy received for a given area is LESS at the poles and GREATEST at the equator |
|
|
Convection Cells |
-what happens when different densities exist within a gas/fluid -colder, denser fluid descends and settles below warmer, less dense fluid
|
|
|
Hadley cells |
variation in insolation (amount of solar energy received) creates convection cells (differences in density) on a global scale |
|
|
Rising (warm) air in the equator... |
condenses to form clouds and rain |
|
|
Descending (cold) air in the mid-latitude causes... |
clear skies and desert climates |
|
|
Global climactic zones reflect... |
the Hadley circulation |
|
|
Climactic zones migrate... |
north and south with the seasons |
|
|
Wind in desert areas: |
important agent of sediment transport |
|
|
Wind in deserts transports... |
Dust |
|
|
Sand in deserts is transported by... |
saltatation |
|
|
Windblown sand |
-mainly quartz -well-sorted |
|
|
Deflation |
wind removes sand and dust from desert, leaves behind desert pavement |
|
|
Erosion by sand |
wind blown sand IS an agent of erosion |
|
|
Motion of a sand dune: |
-wind ERODES sand from windward side of dune -sand is DEPOSITED on other side of dune (lee side) |
|
|
Cross-bedding in sand dunes: |
horizontal units, composed of incline layers |
|
|
Barchan dunes |
-individual crescent dunes with points downwind -form when sand supply is limited and winds are unidirectional -common in rocky deserts |
|
|
Transverse dunes |
-crests lie perpendicular to wind direction -form when sand is abundant and wind is unidirectional common in coastal environments |
|
|
Longitudinal dunes |
-crests are parallel to wind direction -form when winds move in direction with the seasons |
|
|
Most important agent of erosion in deserts: |
water |
|
|
Alluvial fans |
-in deserts -channels with vertical sides and flat bottoms |
|
|
Desert streams |
-usually seasonal -prone to flash flooding |
|
|
Pediments |
-desert erosion produces steep mountain fronts that retreat -leaves a flat eroded surface surface known as pediment |
|
|
Internal drainage in deserts |
-internal drainage is common -water ends up in playa lakes |
|
|
Playa lakes |
-temporary, shallow lakes with natural mineral (evaporite) deposits -ex/ Sahara |
