Your SlideShare is downloading. ×
Desert landscapes dominated by wind
Upcoming SlideShare
Loading in...5

Thanks for flagging this SlideShare!

Oops! An error has occurred.

Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Desert landscapes dominated by wind


Published on

Published in: Education, Technology

1 Like
  • Be the first to comment

No Downloads
Total Views
On Slideshare
From Embeds
Number of Embeds
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

No notes for slide


  • 1. Desert LandscapesDominated by Wind
  • 2. “We don’t survive the desert, we live here” - Pima Indian
  • 3. Deserts: where & why Earth’s dry regions: 30% of all land 2 climate types of dry regions: ◦ desert (arid) ◦ steppe (semi-arid, surrounds deserts) Question:How much rain do deserts get every year? ◦ Sahara Desert receives as little as 2mm and as much as 100mm of precipitation per year
  • 4. Climate Graphs – Semi-arid and AridWhat do you notice about the minimum and maximum temperatures?What do you notice about the amount of precipitation?
  • 5. Deserts: where & why What causes deserts? Global distribution of ◦ air pressure ◦ wind Relationship between ◦ rainfall ◦ evaporation
  • 6. Deserts: where & why Low-latitude deserts ◦ Tropic of Cancer ◦ Tropic of Capricorn In contrast…. ◦ Equator:  hot air  rises to 15-20 km  low pressure belt
  • 7. Deserts: where & why
  • 8. Deserts: where & why
  • 9. Deserts: where & why
  • 10. Deserts: where & why
  • 11. Deserts: where & why Middle-latitude deserts (ie. 45°N) ◦ exist in rain shadows.
  • 12. Deserts: where & whyMiddle-latitude deserts
  • 13. The Great Basin Basin (valley) and Range (mountains) topography ◦ mountainous desert landscape ◦ Nevada, Arizona, California, Utah ◦ Death Valley, Mojave Desert, Great Salt Lake
  • 14. Great Salt Lake, Utah
  • 15. Evaporation > Precipitation Playa: ephemeral (not existing all year long) lake beds that consist of salt and mud flats Spotted Lake, just outside of Osoyoos, BC
  • 16. Wind erosion + deposition Wind erosion: Important in arid environments Example…Sand dune shape depends on: ◦ Flat or hilly? ◦ How much sand? ◦ Winds steady or intermittent? ◦ Wind direction constant? ◦ Vegetation present?
  • 17. Wind erosion Desert pavement
  • 18. Wind erosion Deflation: the process of wind removing silt and sand-sized particles
  • 19. Wind erosion + deposition Ergs: seas of dunes
  • 20. Wind erosion + deposition Sand dune formation
  • 21. Wind erosion Ventifacts: rocks abraded, pitted, polished by windblown sand
  • 22. Wind Deposition Loess from Aeolian (or Eolian) transportation: ◦ Deposit of wind- blown silt and clay in angular grains and weakly cemented by calcite ◦ Develop rich, fertile soils
  • 23. Water Erosion Wadi: a dried up river bed that only has water during rainy season Town of WadiTiwi, Oman
  • 24. Water Erosion  Hoodoos (or fairy chimneys): column of soft sedimentary rock often with resistant layer of “cap” rock on top  Water flows through badlands causing further erosion to theBryce Canyon National Park, Utah spires
  • 25. Water ErosionFairy chimneys that people still live inside in Cappadocia,Turkey
  • 26. Water Erosion  Antelope Slot Canyons, Page, AZ  Flash floods from localized thunderstorms carry sediments that abrade and polish the sandstone
  • 27. Water ErosionMesa: a flat-topped “table” formed bydifferential erosion of softer rockunderneath a layer of “cap” rock
  • 28. Water Erosion Butte: a smaller version of a mesa
  • 29. Water Erosion  Pedestal rock: softer rock erodes quicker than resistant “cap” rock
  • 30. Water DepositionAlluvial Fan: deposition of sediments as rivers or flashfloods leave mountain ranges and spread into thevalley
  • 31. Water Deposition Bajada: several adjacent alluvial fans that have merged together