Deserts

definition - less than 25 cm of rain each year; water is more important than wind, but wind is more important in deserts than in other areas; weathering is slower than in other environments - mountains more jagged and rugged

Distribution: 20-30 latitude, distance from ocean, rainshadow

Erosion
water: little vegetation makes erosion easy
wind: abrasion can play a major role and sculpt rocks; deflation - desert pavement

Transport
water: ephemeral streams periodically carry large sediment load due to lack of vegetation
wind: low competence but high capacity - often moves sediment through saltation

Deposition
water: ephemeral braided streams; alluvial fans; playa lakes, evaporites
wind: sand dunes - cross-bedding, dune migration; barchan dunes, transverse dunes, longitudinal dunes, parabolic dunes, star dunes

Describe 3 factors that control the distribution of deserts.

Explain how the process of deflation forms desert pavement.

How do dunes migrate? Why?