Deserts Lecture Notes

Flashcards about Deserts

Latitudinal Bands

Controlled by atmospheric circulation, causing deserts due to consistently dry, descending air.

Rainshadow Effect

Creates deserts on the leeward side of mountain ranges due to the blocking of moist air.

Eolian Transport

Refers to sediment transport by wind, common in desert environments.

Fluvial Transport

Refers to sediment transport by water; while less common, it still shapes desert landscapes.

Suspension Transport

A mode of wind transport where fine particles are carried over very long distances in the air.

Saltation

The process where most sand travels by bouncing or skipping along the ground.

Creep

Surface movement of larger particles in the direction of wind.

Deflation

An erosional process in deserts involving the lowering of the surface through the removal of fine particles by wind.

Desert Pavement

A surface concentration of larger pebbles left behind after deflation removes fine particles.

Abrasion

An erosional process in deserts where surfaces are worn down by the impact of wind-blown sand particles.

Yardangs

Erosional features shaped by wind erosion.

Base Level

An imaginary surface below which deposition dominates and above which erosion dominates.

Dunes

Depositional landforms created by the accumulation of sand.

Slipface

The steep, downwind side of a sand dune where sand cascades down.

Angle of Repose

The steepest angle at which a material can be piled without slumping.

Crossbeds

Sedimentary structures formed by the migration of dunes and preserved in the rock record.

Sand Ripples

Small ridges on the sand surface, often inversely graded and controlled by saltation length.

Barchan Dunes

Crescent-shaped dunes with horns pointing downwind, typically found where sand supply is limited and wind direction is uniform.

Desertification

Land degradation in dry areas due to climatic variations and human activities.