Question

Name two chief types of sand dunes.

Answer 1

1. Barchan Dunes: These dunes are crescent-shaped with the tips pointing in the direction of the wind. Barchans are typically formed in areas with limited sand supply and a consistent wind direction. They move over time, and their size can change based on the strength of the wind. These dunes are common in deserts such as the Sahara and Central Asia, where the wind blows consistently in one direction.

2. Longitudinal Dunes (Seifs): Longitudinal dunes, also known as seifs, are long, narrow ridges of sand that form parallel to the prevailing wind direction. These dunes occur in deserts with a more abundant sand supply and a variable wind direction, which causes the dunes to align in parallel lines. They are often larger and longer than Barchans and can be found in deserts like the Libyan Desert and Saudi Arabia.