Deserts Flashcards
1
Q
What is a desert?
A
Landscape/region that receives very little precipitation - less than 10in (250mm) / year
2
Q
Aeolian Process
A
How wind shaped the surface of Earth and other planets
3
Q
Traits of deserts
A
- 30% of Earth’s surface
- Large seasonal & daily temp. range due to low humidity
- Water traps infrared radiation, dry desert cannot block sunlight in the day, or trap heat at night
4
Q
Types of Sediment Transportation
A
- Suspension: Wind near earth surface can suspend and scatter particles <0.2mm
- Saltation: Movement of <1cm particles that skip/jump at 1/2 - 1/3 the speed of wind
- Creep: Larger particles are pushed along ground by Saltation particles
5
Q
Rainshadow effect
A
A rain shadow is a dry area on one side of a mountain or mountain range. The water vapor in the moist air condenses to form clouds and finally rain as it rises up with the mountains. This rain falls on the near side of the mountain, causing the air that continues on the far side of the mountain to be dry.
6
Q
Polar Desert
A
Sinking cold air that can’t hold much moisture
7
Q
Types of Deposition
A
- Sand Sheets: Flat sheets of sand surfaced by grains too big for saltation (40% of Aeolian surfaces)
- Ripples: Small crests w/ direction of the wind, length of jumps during saltation corresponds to downwind side
- Dunes: Ridge w/ gentle slopes on wind side & steep slopes on downwind side.
8
Q
Important to know
A
Most deserts are 10-30 degrees North & South - related to atmospheric cells.
