arid landforms

60 %
40 %
Information about arid landforms

Published on January 8, 2009

Author: aSGuest9680


Arid Landforms : Arid Landforms Basic Concepts : Basic Concepts I. Most deserts exhibit highly angular landscapes. mechanical weathering dominates angular particles of weathered rock; bedrock outcrops little soil or vegetation to soften landscape II. Softer, more rounded landscapes appear where deposition is predominant. dunes III. Desert rainfall is infrequent, intense, and unreliable. intense flash flooding, intense erosion ephemeral streams Slide 5: Death Valley, July 15, 1999 Slide 6: Las Vegas Flash Flood Types of Deserts : Types of Deserts Erg - sea of sand largest are in Sahara and Arabian Deserts, sand covers about 20% of world’s deserts vegetation rare sand probably formed during more humid climate Slide 8: Death Valley, California Types of Deserts : Types of Deserts Reg - desert “pavement” of pebbles and stones all small materials and sand removed by wind may be very thin coating of stones Slide 10: A gibber plain in Australia Desert pavement Slide 11: Hamada - bedrock predominates Slide 12: Desert varnish - oxidation of iron and manganese, useful for dating desert surfaces DESERT FLUVIAL PROCESSES/LANDFORMS : DESERT FLUVIAL PROCESSES/LANDFORMS Fluvial Erosion - rare, intense flash floods. steep slopes; steep-walled canyons; washes, wadis, arroyos, canyons. fluvial systems decrease in discharge downstream Fluvial Transportation - large amounts of rock and sand moved short distances. Fluvial Deposition – where water slows on flat playas material is deposited and sorted by size. alluvial fans rock debris in piedmont region Slide 14: Arroyo Slide 15: Virga Slide 16: Joshua Tree N.P. Slide 17: Slot Canyon Slide 18: The Narrows, Zion N.P., Utah AEOLIAN (WIND) PROCESSES/LANDFORMS : AEOLIAN (WIND) PROCESSES/LANDFORMS Aeolian Erosion - much less effective than fluvial deflation - the movement of small particles abrasion - polishes and etches exposed surfaces Aeolian Transportation - moves nothing bigger than sand dust storms - can extend thousands of feet up sand storms - only very near the surface Aeolian Deposition - dunes form and shift where winds and terrain combine to slow the winds or block the movement of dunes. Slide 21: Dust Storm, Senegal Sand Storm AEOLIAN (WIND) PROCESSES/LANDFORMS : AEOLIAN (WIND) PROCESSES/LANDFORMS Types of Dunes : Types of Dunes BARCHAN TRANSVERSE DUNES SEIFS Types of Dunes : Types of Dunes Barchans - migrating crescent dune with horns pointing downwind; form where strong winds blow in a consistent direction. Move fast. Common in central Asia and Sahara. Can reach hundreds of feet in height. Slide 25: Transverse Dunes - parallel waves of crescent dunes perpendicular to wind direction; migrate downwind. Found in areas with large supply of sand. Slide 26: Seifs - multiple very long narrow, parallel dunes. May be caused in areas with at least two dominant wind directions. Can be tens of miles long. Common outside of U.S. Slide 27: Namib Desert Star Dunes BASIN AND RANGE TOPOGRAPHY : BASIN AND RANGE TOPOGRAPHY Slide 29: Piedmont - gently sloping land that extends out from base of mountains. Pediment - sloping bedrock at base that develops. Slide 30: Badwater, Death Valley, CA Slide 32: Playas Mesa and Scarp Topography : Mesa and Scarp Topography Slide 34: Differential Erosion Slide 38: Uluru (Ayer’s Rock), Australia Slide 39: Inselberg - “island mountains” rise abruptly out of desert landscapes Bornhardt - highly resistant rock landform; a type of inselberg. Kata Tjuta (The Olgas), Australia Slide 40: Bornhardt, Arches National Park, Utah Slide 41: Delicate Arch, Arches National Park, Utah

Add a comment

Related presentations

Related pages


MAJOR LANDFORMS IN (SEMI-)ARID REGIONS Arid and semi-arid regions are not a morphotectonic category as such. They are distinguished on the basis of the ...
Read more

The Arid Landforms and Cycle of Erosion

William M. Davis considered the arid cycle as a modification imposed upon the humid cycle. Davis’ ideal arid cycle exists in a desert, especially in ...
Read more

Arides Klima – Wikipedia

arid : Großer Salzsee ≈ 130 : semiarid : Weblinks Wetterlexikon - Arides Klima ...
Read more

Arid - Wikipedia, the free encyclopedia

A region is arid when it is characterized by a severe lack of available water, to the extent of hindering or preventing the growth and development of plant ...
Read more

Arid Region Landforms and Eolian Processes 18 - Education

Arid Region Landforms 18 and Eolian Processes In most deserts, running water operates only occasionally, so it may seem odd that water rather than wind is ...
Read more

Arid Landforms - Wind Eroded - Water Eroded – PMF IAS

Arid Landforms Water Eroded Arid Landforms – Rill, Gully, Ravine, Badland Topography, Bolsons, Playas, Pediments, Bajada etc.. Wind Eroded Arid Landforms ...
Read more

Arid Landforms - El Camino College

Title: Arid Landforms Author: Michael Reed Last modified by: Michael Reed Created Date: 10/23/2003 5:47:45 AM Document presentation format: On-screen Show
Read more