SlideShare a Scribd company logo
DESERTS AND WIND
ACTION
DESERTS AND WIND ACTION
• Desert regions and wind erosion
• Desert and adjacent region
• desert
• region which has an arid climate
• steppe
• region adjacent to a desert with semiarid
climate
Desert (arid climate) and
steppe (semiarid climate) areas on Earth
DESERTS AND WIND ACTION
DESERTS AND WIND ACTION
• Wind erosion processes
• deflation is the removal of rock waste from
the land by the wind
• blowout or deflation hollow is a depression
excavated by the wind in materials as sand
and silt deposits easily eroded because of a
lack of the presence of adequate vegetation
which impedes deflation
Blowout or deflation hollow
DESERTS AND WIND ACTION
DESERTS AND WIND ACTION
Deflation Hollow---Blowout
abrasion is the “sandblasting”effect
on materials caused by the impact
with particles carried by the wind—
frosted windows in houses and
ventifacts form
DESERTS AND WIND ACTION
DESERTS AND WIND ACTION
• Wind erosion loads
• suspended load
• suspended wind blown particles
• consists primarily of silt or clay size
particles and if highly concentrated can
result in dust storms
• deposition of the suspended load can result
in large deposits of loess lacking layering
or stratification
DESERTS AND WIND ACTION
Dust Storms
DESERTS AND WIND ACTION
Loess Deposits
DESERTS AND WIND ACTION
• bed load
• particles bounced along the ground
• usually consists of sand size particles
• accumulation of the bed load forms desert
sand dunes which can migrate
easily(active dunes)
• Active sand dunes
• Nature of active (unstable) dunes
• dune profile
• consists of a more gentle windward slope
and steeper leeward slope or slipface
Dune profile
DESERTS AND WIND ACTION
DESERTS AND WIND ACTION
• shifting dunes
• shift downwind and can bury roads, airport
runways, homes, etc.
• Categories of active dunes
• based on shape of dune in plan view
• barchan
• crescent shaped with convex portion
facing the wind direction
• formed with a constant wind direction and
limited sand supply
Barchan dunes
DESERTS AND WIND ACTION
DESERTS AND WIND ACTION
• transverse
• elongated perpendicular to direction of
wind
• formed with a constant direction of wind
and large supply of sand
DESERTS AND WIND ACTION
• longitudinal or seif
• elongated in general direction of wind
• formed with slightly different wind
directions and limited sand supply
DESERTS AND WIND ACTION
• star or complex
• formed with variable wind direction
DESERTS AND WIND ACTION
• Desert landscape and evolution
• Alluvial fan
• fan shaped deposit formed at the foot of
mountains in the desert valley or basin
a bajada is an apron of sediment
resulting from a coalescence of
alluvial fans
DESERTS AND WIND ACTION
Playa lake and playa
a temporary shallow lake formed in the central
basin of a desert during a rare abundant
rainfall--a playa is the dry flat lake bed that
remains
DESERTS AND WIND ACTION
DESERTS AND WIND ACTION
• Inselberg
• an isolated erosional remnant present after
long term erosion of mountain areas which
are reduced to these bedrock knobs elevated
above the surrounding sediment filled basin
DESERTS AND WIND ACTION
• Pediment
• a carved gently sloping erosional surface on
the bedrock in a desert mountainous area
Stages of landscape in mountainous desert regions
DESERTS AND WIND ACTION
DESERTS AND WIND ACTION
• Inactive or stable dune---mostly non-desert
• Parabolic dune(foredune)
• formed along coastlines of oceans or large
lakes
• winds cause blowouts in sand resulting in a
crescent shape with the concave side facing
the prevailing wind direction
THAT’S ALL THE
CYBER GEOLOGY
COURSE FOLKS

More Related Content

Similar to deserts-wind.ppt

Geologylecture19 130505151645-phpapp02
Geologylecture19 130505151645-phpapp02Geologylecture19 130505151645-phpapp02
Geologylecture19 130505151645-phpapp02
Cleophas Rwemera
 
Geology lecture 19
Geology lecture 19Geology lecture 19
Geology lecture 19
Lauren Adams
 
A2 Physical Geography - Hot arid and Semi Arid Environment
 A2 Physical Geography - Hot arid and Semi Arid Environment A2 Physical Geography - Hot arid and Semi Arid Environment
A2 Physical Geography - Hot arid and Semi Arid Environment
nazeema khan
 
Periglacia processes and their landscapes and landforms
Periglacia processes and their landscapes and landformsPeriglacia processes and their landscapes and landforms
Periglacia processes and their landscapes and landforms
James Foster
 
Lesson 8 periglacial processes and their landscapes and landforms
Lesson 8   periglacial processes and their landscapes and landformsLesson 8   periglacial processes and their landscapes and landforms
Lesson 8 periglacial processes and their landscapes and landforms
James Foster
 
Wind.agent- Geomorhology Chapter
Wind.agent- Geomorhology ChapterWind.agent- Geomorhology Chapter
Wind.agent- Geomorhology Chapter
Kaium Chowdhury
 
SEDIMENT CHARACTERSTICES IN DESERTIC ENVIRONMNET.pptx
SEDIMENT  CHARACTERSTICES IN DESERTIC ENVIRONMNET.pptxSEDIMENT  CHARACTERSTICES IN DESERTIC ENVIRONMNET.pptx
SEDIMENT CHARACTERSTICES IN DESERTIC ENVIRONMNET.pptx
Tribhuvan University
 
aseminaronaeolianlandforms-170405120427 (1).pdf
aseminaronaeolianlandforms-170405120427 (1).pdfaseminaronaeolianlandforms-170405120427 (1).pdf
aseminaronaeolianlandforms-170405120427 (1).pdf
MuuminCabdulle
 
aeolian landforms
 aeolian landforms aeolian landforms
aeolian landforms
Pramoda Raj
 
Weathering agents
Weathering agentsWeathering agents
Weathering agents
Kaustubh Sane
 
Arid Aeolian Landform
Arid Aeolian LandformArid Aeolian Landform
Arid Aeolian Landform
aikyatha
 
Chapter si xx1
Chapter si xx1Chapter si xx1
Chapter si xx1
IDIUganda
 
Major landforms
Major landformsMajor landforms
Major landforms
ananyasharma833350
 
Wind deposition, loess and dunes
Wind deposition, loess and dunesWind deposition, loess and dunes
Wind deposition, loess and dunes
Kamran Shehzad
 
Landforms on the earth
Landforms on the earthLandforms on the earth
Landforms on the earth
Marissia226
 
Wind / Aeolian landforms
Wind / Aeolian landformsWind / Aeolian landforms
Wind / Aeolian landforms
Karthikeyan C
 
Depositional environment of sandstone and facie
Depositional environment of sandstone and facieDepositional environment of sandstone and facie
Depositional environment of sandstone and facie
MuhammadJawwad28
 
wind landforms.pptx
wind landforms.pptxwind landforms.pptx
wind landforms.pptx
Rajshahi university
 
leaves.ppt
leaves.pptleaves.ppt
leaves.ppt
SaadTaman
 
SOIL PROFILE SOIL EROSION SOIL CONSERVATION CONTROL ON FLOODS
SOIL  PROFILE  SOIL EROSION SOIL CONSERVATION  CONTROL ON FLOODS            SOIL  PROFILE  SOIL EROSION SOIL CONSERVATION  CONTROL ON FLOODS
SOIL PROFILE SOIL EROSION SOIL CONSERVATION CONTROL ON FLOODS
AMRITHA K.T.K
 

Similar to deserts-wind.ppt (20)

Geologylecture19 130505151645-phpapp02
Geologylecture19 130505151645-phpapp02Geologylecture19 130505151645-phpapp02
Geologylecture19 130505151645-phpapp02
 
Geology lecture 19
Geology lecture 19Geology lecture 19
Geology lecture 19
 
A2 Physical Geography - Hot arid and Semi Arid Environment
 A2 Physical Geography - Hot arid and Semi Arid Environment A2 Physical Geography - Hot arid and Semi Arid Environment
A2 Physical Geography - Hot arid and Semi Arid Environment
 
Periglacia processes and their landscapes and landforms
Periglacia processes and their landscapes and landformsPeriglacia processes and their landscapes and landforms
Periglacia processes and their landscapes and landforms
 
Lesson 8 periglacial processes and their landscapes and landforms
Lesson 8   periglacial processes and their landscapes and landformsLesson 8   periglacial processes and their landscapes and landforms
Lesson 8 periglacial processes and their landscapes and landforms
 
Wind.agent- Geomorhology Chapter
Wind.agent- Geomorhology ChapterWind.agent- Geomorhology Chapter
Wind.agent- Geomorhology Chapter
 
SEDIMENT CHARACTERSTICES IN DESERTIC ENVIRONMNET.pptx
SEDIMENT  CHARACTERSTICES IN DESERTIC ENVIRONMNET.pptxSEDIMENT  CHARACTERSTICES IN DESERTIC ENVIRONMNET.pptx
SEDIMENT CHARACTERSTICES IN DESERTIC ENVIRONMNET.pptx
 
aseminaronaeolianlandforms-170405120427 (1).pdf
aseminaronaeolianlandforms-170405120427 (1).pdfaseminaronaeolianlandforms-170405120427 (1).pdf
aseminaronaeolianlandforms-170405120427 (1).pdf
 
aeolian landforms
 aeolian landforms aeolian landforms
aeolian landforms
 
Weathering agents
Weathering agentsWeathering agents
Weathering agents
 
Arid Aeolian Landform
Arid Aeolian LandformArid Aeolian Landform
Arid Aeolian Landform
 
Chapter si xx1
Chapter si xx1Chapter si xx1
Chapter si xx1
 
Major landforms
Major landformsMajor landforms
Major landforms
 
Wind deposition, loess and dunes
Wind deposition, loess and dunesWind deposition, loess and dunes
Wind deposition, loess and dunes
 
Landforms on the earth
Landforms on the earthLandforms on the earth
Landforms on the earth
 
Wind / Aeolian landforms
Wind / Aeolian landformsWind / Aeolian landforms
Wind / Aeolian landforms
 
Depositional environment of sandstone and facie
Depositional environment of sandstone and facieDepositional environment of sandstone and facie
Depositional environment of sandstone and facie
 
wind landforms.pptx
wind landforms.pptxwind landforms.pptx
wind landforms.pptx
 
leaves.ppt
leaves.pptleaves.ppt
leaves.ppt
 
SOIL PROFILE SOIL EROSION SOIL CONSERVATION CONTROL ON FLOODS
SOIL  PROFILE  SOIL EROSION SOIL CONSERVATION  CONTROL ON FLOODS            SOIL  PROFILE  SOIL EROSION SOIL CONSERVATION  CONTROL ON FLOODS
SOIL PROFILE SOIL EROSION SOIL CONSERVATION CONTROL ON FLOODS
 

More from AdnanKhan153072

igneous rocks classification #6.pdf
igneous rocks classification #6.pdfigneous rocks classification #6.pdf
igneous rocks classification #6.pdf
AdnanKhan153072
 
Geomorphology Presentation 1.pptx
Geomorphology Presentation 1.pptxGeomorphology Presentation 1.pptx
Geomorphology Presentation 1.pptx
AdnanKhan153072
 
jhelum group.pdf final.pdf
jhelum group.pdf final.pdfjhelum group.pdf final.pdf
jhelum group.pdf final.pdf
AdnanKhan153072
 
7. Metamorphic Facies-1.pdf
7. Metamorphic Facies-1.pdf7. Metamorphic Facies-1.pdf
7. Metamorphic Facies-1.pdf
AdnanKhan153072
 
1. Introduction to Structural Geology.pdf
1. Introduction to Structural Geology.pdf1. Introduction to Structural Geology.pdf
1. Introduction to Structural Geology.pdf
AdnanKhan153072
 
1_ Introduction to Optical Mineralogy, Light & Theories-converted.pdf
1_ Introduction to Optical Mineralogy, Light & Theories-converted.pdf1_ Introduction to Optical Mineralogy, Light & Theories-converted.pdf
1_ Introduction to Optical Mineralogy, Light & Theories-converted.pdf
AdnanKhan153072
 

More from AdnanKhan153072 (6)

igneous rocks classification #6.pdf
igneous rocks classification #6.pdfigneous rocks classification #6.pdf
igneous rocks classification #6.pdf
 
Geomorphology Presentation 1.pptx
Geomorphology Presentation 1.pptxGeomorphology Presentation 1.pptx
Geomorphology Presentation 1.pptx
 
jhelum group.pdf final.pdf
jhelum group.pdf final.pdfjhelum group.pdf final.pdf
jhelum group.pdf final.pdf
 
7. Metamorphic Facies-1.pdf
7. Metamorphic Facies-1.pdf7. Metamorphic Facies-1.pdf
7. Metamorphic Facies-1.pdf
 
1. Introduction to Structural Geology.pdf
1. Introduction to Structural Geology.pdf1. Introduction to Structural Geology.pdf
1. Introduction to Structural Geology.pdf
 
1_ Introduction to Optical Mineralogy, Light & Theories-converted.pdf
1_ Introduction to Optical Mineralogy, Light & Theories-converted.pdf1_ Introduction to Optical Mineralogy, Light & Theories-converted.pdf
1_ Introduction to Optical Mineralogy, Light & Theories-converted.pdf
 

Recently uploaded

Call Girls Bangalore 9024918724 Independent Call Girl Service Bangalore
Call Girls Bangalore 9024918724 Independent Call Girl Service BangaloreCall Girls Bangalore 9024918724 Independent Call Girl Service Bangalore
Call Girls Bangalore 9024918724 Independent Call Girl Service Bangalore
namratasinha41
 
一比一原版美国南加州大学毕业证(南加大学位证)如何办理
一比一原版美国南加州大学毕业证(南加大学位证)如何办理一比一原版美国南加州大学毕业证(南加大学位证)如何办理
一比一原版美国南加州大学毕业证(南加大学位证)如何办理
43ekmxzp
 
Call Girls Kolkata 7339748667 Independent Call Girl Service Kolkata
Call Girls Kolkata 7339748667 Independent Call Girl Service KolkataCall Girls Kolkata 7339748667 Independent Call Girl Service Kolkata
Call Girls Kolkata 7339748667 Independent Call Girl Service Kolkata
namratasinha41
 
3. Calcium role in muscle contraction. Biochemistry
3. Calcium role in muscle contraction. Biochemistry3. Calcium role in muscle contraction. Biochemistry
3. Calcium role in muscle contraction. Biochemistry
immortalabhi007
 
Call Girls Chandigarh ✔️ 7339748667 ✔️ With No Advance Payment
Call Girls Chandigarh ✔️ 7339748667 ✔️ With No Advance PaymentCall Girls Chandigarh ✔️ 7339748667 ✔️ With No Advance Payment
Call Girls Chandigarh ✔️ 7339748667 ✔️ With No Advance Payment
prijesh mathew
 
Mass Production of Trichogramma sp..pptx
Mass Production of Trichogramma sp..pptxMass Production of Trichogramma sp..pptx
Mass Production of Trichogramma sp..pptx
SwastikBhattacharjya
 
Environmental Science Project Class 10th year 2022 ICSE
Environmental Science Project Class 10th year 2022 ICSEEnvironmental Science Project Class 10th year 2022 ICSE
Environmental Science Project Class 10th year 2022 ICSE
rushufaddu1311
 
一比一原版美国加利福尼亚大学欧文分校毕业证(ucirvine学位证)如何办理
一比一原版美国加利福尼亚大学欧文分校毕业证(ucirvine学位证)如何办理一比一原版美国加利福尼亚大学欧文分校毕业证(ucirvine学位证)如何办理
一比一原版美国加利福尼亚大学欧文分校毕业证(ucirvine学位证)如何办理
twqryq79
 
Call Girls Goa ☎️ +91-7426014248 😍 Goa Call Girl Beauty Girls Goa Escort
Call Girls Goa ☎️ +91-7426014248 😍 Goa Call Girl Beauty Girls Goa EscortCall Girls Goa ☎️ +91-7426014248 😍 Goa Call Girl Beauty Girls Goa Escort
Call Girls Goa ☎️ +91-7426014248 😍 Goa Call Girl Beauty Girls Goa Escort
zoyat9250
 
Organic Nutrient Resources and its biofortification
Organic Nutrient Resources and its biofortificationOrganic Nutrient Resources and its biofortification
Organic Nutrient Resources and its biofortification
VRMageshen
 
Exploring low emissions development opportunities in food systems
Exploring low emissions development opportunities in food systemsExploring low emissions development opportunities in food systems
Exploring low emissions development opportunities in food systems
CIFOR-ICRAF
 
INDONESIA Long-Term Strategy for Low Carbon and Climate Resilience 2050
INDONESIA Long-Term Strategy for Low Carbon and Climate Resilience 2050INDONESIA Long-Term Strategy for Low Carbon and Climate Resilience 2050
INDONESIA Long-Term Strategy for Low Carbon and Climate Resilience 2050
Azka Fauzan
 
SOIL AND ITS FORMATION bjbhjbhvhvhjvhj .pptx
SOIL AND ITS FORMATION bjbhjbhvhvhjvhj .pptxSOIL AND ITS FORMATION bjbhjbhvhvhjvhj .pptx
SOIL AND ITS FORMATION bjbhjbhvhvhjvhj .pptx
anmolbansal1969
 
一比一原版美国南加州大学毕业证如何办理
一比一原版美国南加州大学毕业证如何办理一比一原版美国南加州大学毕业证如何办理
一比一原版美国南加州大学毕业证如何办理
yfvet
 
一比一原版(durham学位证书)英国杜伦大学毕业证如何办理
一比一原版(durham学位证书)英国杜伦大学毕业证如何办理一比一原版(durham学位证书)英国杜伦大学毕业证如何办理
一比一原版(durham学位证书)英国杜伦大学毕业证如何办理
fgatp
 
一比一原版美国南加州大学毕业证(usc学位证)如何办理
一比一原版美国南加州大学毕业证(usc学位证)如何办理一比一原版美国南加州大学毕业证(usc学位证)如何办理
一比一原版美国南加州大学毕业证(usc学位证)如何办理
43ekmxzp
 
2024-06-22 Composting at Home 101 on Zoom
2024-06-22 Composting at Home 101  on Zoom2024-06-22 Composting at Home 101  on Zoom
2024-06-22 Composting at Home 101 on Zoom
Ellen Book
 
一比一原版(Glasgow毕业证)英国格拉斯哥大学毕业证如何办理
一比一原版(Glasgow毕业证)英国格拉斯哥大学毕业证如何办理一比一原版(Glasgow毕业证)英国格拉斯哥大学毕业证如何办理
一比一原版(Glasgow毕业证)英国格拉斯哥大学毕业证如何办理
aonx8o5f
 
一比一原版美国迈阿密大学毕业证如何办理
一比一原版美国迈阿密大学毕业证如何办理一比一原版美国迈阿密大学毕业证如何办理
一比一原版美国迈阿密大学毕业证如何办理
yfvet
 
Welcoming Wolves Back Home and the Effects of Manifest Destiny
Welcoming Wolves Back Home and the Effects of Manifest DestinyWelcoming Wolves Back Home and the Effects of Manifest Destiny
Welcoming Wolves Back Home and the Effects of Manifest Destiny
Megan Hughes
 

Recently uploaded (20)

Call Girls Bangalore 9024918724 Independent Call Girl Service Bangalore
Call Girls Bangalore 9024918724 Independent Call Girl Service BangaloreCall Girls Bangalore 9024918724 Independent Call Girl Service Bangalore
Call Girls Bangalore 9024918724 Independent Call Girl Service Bangalore
 
一比一原版美国南加州大学毕业证(南加大学位证)如何办理
一比一原版美国南加州大学毕业证(南加大学位证)如何办理一比一原版美国南加州大学毕业证(南加大学位证)如何办理
一比一原版美国南加州大学毕业证(南加大学位证)如何办理
 
Call Girls Kolkata 7339748667 Independent Call Girl Service Kolkata
Call Girls Kolkata 7339748667 Independent Call Girl Service KolkataCall Girls Kolkata 7339748667 Independent Call Girl Service Kolkata
Call Girls Kolkata 7339748667 Independent Call Girl Service Kolkata
 
3. Calcium role in muscle contraction. Biochemistry
3. Calcium role in muscle contraction. Biochemistry3. Calcium role in muscle contraction. Biochemistry
3. Calcium role in muscle contraction. Biochemistry
 
Call Girls Chandigarh ✔️ 7339748667 ✔️ With No Advance Payment
Call Girls Chandigarh ✔️ 7339748667 ✔️ With No Advance PaymentCall Girls Chandigarh ✔️ 7339748667 ✔️ With No Advance Payment
Call Girls Chandigarh ✔️ 7339748667 ✔️ With No Advance Payment
 
Mass Production of Trichogramma sp..pptx
Mass Production of Trichogramma sp..pptxMass Production of Trichogramma sp..pptx
Mass Production of Trichogramma sp..pptx
 
Environmental Science Project Class 10th year 2022 ICSE
Environmental Science Project Class 10th year 2022 ICSEEnvironmental Science Project Class 10th year 2022 ICSE
Environmental Science Project Class 10th year 2022 ICSE
 
一比一原版美国加利福尼亚大学欧文分校毕业证(ucirvine学位证)如何办理
一比一原版美国加利福尼亚大学欧文分校毕业证(ucirvine学位证)如何办理一比一原版美国加利福尼亚大学欧文分校毕业证(ucirvine学位证)如何办理
一比一原版美国加利福尼亚大学欧文分校毕业证(ucirvine学位证)如何办理
 
Call Girls Goa ☎️ +91-7426014248 😍 Goa Call Girl Beauty Girls Goa Escort
Call Girls Goa ☎️ +91-7426014248 😍 Goa Call Girl Beauty Girls Goa EscortCall Girls Goa ☎️ +91-7426014248 😍 Goa Call Girl Beauty Girls Goa Escort
Call Girls Goa ☎️ +91-7426014248 😍 Goa Call Girl Beauty Girls Goa Escort
 
Organic Nutrient Resources and its biofortification
Organic Nutrient Resources and its biofortificationOrganic Nutrient Resources and its biofortification
Organic Nutrient Resources and its biofortification
 
Exploring low emissions development opportunities in food systems
Exploring low emissions development opportunities in food systemsExploring low emissions development opportunities in food systems
Exploring low emissions development opportunities in food systems
 
INDONESIA Long-Term Strategy for Low Carbon and Climate Resilience 2050
INDONESIA Long-Term Strategy for Low Carbon and Climate Resilience 2050INDONESIA Long-Term Strategy for Low Carbon and Climate Resilience 2050
INDONESIA Long-Term Strategy for Low Carbon and Climate Resilience 2050
 
SOIL AND ITS FORMATION bjbhjbhvhvhjvhj .pptx
SOIL AND ITS FORMATION bjbhjbhvhvhjvhj .pptxSOIL AND ITS FORMATION bjbhjbhvhvhjvhj .pptx
SOIL AND ITS FORMATION bjbhjbhvhvhjvhj .pptx
 
一比一原版美国南加州大学毕业证如何办理
一比一原版美国南加州大学毕业证如何办理一比一原版美国南加州大学毕业证如何办理
一比一原版美国南加州大学毕业证如何办理
 
一比一原版(durham学位证书)英国杜伦大学毕业证如何办理
一比一原版(durham学位证书)英国杜伦大学毕业证如何办理一比一原版(durham学位证书)英国杜伦大学毕业证如何办理
一比一原版(durham学位证书)英国杜伦大学毕业证如何办理
 
一比一原版美国南加州大学毕业证(usc学位证)如何办理
一比一原版美国南加州大学毕业证(usc学位证)如何办理一比一原版美国南加州大学毕业证(usc学位证)如何办理
一比一原版美国南加州大学毕业证(usc学位证)如何办理
 
2024-06-22 Composting at Home 101 on Zoom
2024-06-22 Composting at Home 101  on Zoom2024-06-22 Composting at Home 101  on Zoom
2024-06-22 Composting at Home 101 on Zoom
 
一比一原版(Glasgow毕业证)英国格拉斯哥大学毕业证如何办理
一比一原版(Glasgow毕业证)英国格拉斯哥大学毕业证如何办理一比一原版(Glasgow毕业证)英国格拉斯哥大学毕业证如何办理
一比一原版(Glasgow毕业证)英国格拉斯哥大学毕业证如何办理
 
一比一原版美国迈阿密大学毕业证如何办理
一比一原版美国迈阿密大学毕业证如何办理一比一原版美国迈阿密大学毕业证如何办理
一比一原版美国迈阿密大学毕业证如何办理
 
Welcoming Wolves Back Home and the Effects of Manifest Destiny
Welcoming Wolves Back Home and the Effects of Manifest DestinyWelcoming Wolves Back Home and the Effects of Manifest Destiny
Welcoming Wolves Back Home and the Effects of Manifest Destiny
 

deserts-wind.ppt

  • 2. DESERTS AND WIND ACTION • Desert regions and wind erosion • Desert and adjacent region • desert • region which has an arid climate • steppe • region adjacent to a desert with semiarid climate
  • 3. Desert (arid climate) and steppe (semiarid climate) areas on Earth DESERTS AND WIND ACTION
  • 4. DESERTS AND WIND ACTION • Wind erosion processes • deflation is the removal of rock waste from the land by the wind • blowout or deflation hollow is a depression excavated by the wind in materials as sand and silt deposits easily eroded because of a lack of the presence of adequate vegetation which impedes deflation
  • 5. Blowout or deflation hollow DESERTS AND WIND ACTION
  • 6. DESERTS AND WIND ACTION Deflation Hollow---Blowout
  • 7. abrasion is the “sandblasting”effect on materials caused by the impact with particles carried by the wind— frosted windows in houses and ventifacts form DESERTS AND WIND ACTION
  • 8. DESERTS AND WIND ACTION • Wind erosion loads • suspended load • suspended wind blown particles • consists primarily of silt or clay size particles and if highly concentrated can result in dust storms • deposition of the suspended load can result in large deposits of loess lacking layering or stratification
  • 9. DESERTS AND WIND ACTION Dust Storms
  • 10. DESERTS AND WIND ACTION Loess Deposits
  • 11. DESERTS AND WIND ACTION • bed load • particles bounced along the ground • usually consists of sand size particles • accumulation of the bed load forms desert sand dunes which can migrate easily(active dunes) • Active sand dunes • Nature of active (unstable) dunes • dune profile • consists of a more gentle windward slope and steeper leeward slope or slipface
  • 13. DESERTS AND WIND ACTION • shifting dunes • shift downwind and can bury roads, airport runways, homes, etc. • Categories of active dunes • based on shape of dune in plan view • barchan • crescent shaped with convex portion facing the wind direction • formed with a constant wind direction and limited sand supply
  • 15. DESERTS AND WIND ACTION • transverse • elongated perpendicular to direction of wind • formed with a constant direction of wind and large supply of sand
  • 16. DESERTS AND WIND ACTION • longitudinal or seif • elongated in general direction of wind • formed with slightly different wind directions and limited sand supply
  • 17. DESERTS AND WIND ACTION • star or complex • formed with variable wind direction
  • 18. DESERTS AND WIND ACTION • Desert landscape and evolution • Alluvial fan • fan shaped deposit formed at the foot of mountains in the desert valley or basin
  • 19. a bajada is an apron of sediment resulting from a coalescence of alluvial fans DESERTS AND WIND ACTION
  • 20. Playa lake and playa a temporary shallow lake formed in the central basin of a desert during a rare abundant rainfall--a playa is the dry flat lake bed that remains DESERTS AND WIND ACTION
  • 21. DESERTS AND WIND ACTION • Inselberg • an isolated erosional remnant present after long term erosion of mountain areas which are reduced to these bedrock knobs elevated above the surrounding sediment filled basin
  • 22. DESERTS AND WIND ACTION • Pediment • a carved gently sloping erosional surface on the bedrock in a desert mountainous area
  • 23. Stages of landscape in mountainous desert regions DESERTS AND WIND ACTION
  • 24. DESERTS AND WIND ACTION • Inactive or stable dune---mostly non-desert • Parabolic dune(foredune) • formed along coastlines of oceans or large lakes • winds cause blowouts in sand resulting in a crescent shape with the concave side facing the prevailing wind direction
  • 25. THAT’S ALL THE CYBER GEOLOGY COURSE FOLKS