Table of Contents
What is Sand Dune? Types of Sand Dunes:
Formation of Sand Dunes. Sand Dune – About Types
A sand dune is a hill of sand, typically found in deserts and other arid regions. The formation of sand dunes is affected by wind. The wind can pick up sand from the surface of the ground and carry it away. When this happens, the sand is deposited in a new location, forming a sand dune.
There are three main types of sand dunes: barchan, transverse, and seif. Barchan dunes are crescent-shaped dunes that are typically found in deserts. Transverse dunes are ridges of sand that are found perpendicular to the wind direction. Seif dunes are long, straight dunes that are typically found in deserts.
The shape of a sand dune is also affected by the type of sand that is being deposited. If the sand is fine and has a high water content, the dune will be more curved. If the sand is coarse and has a low water content, the dune will be more straight.
Star Dunes
Star dunes are a type of sand dune that are found in the Sahara desert. They are named for their distinctive shape, which looks like a star when viewed from above. Star dunes are created when strong winds blow sand from one area to another, creating a ridge of sand that is pointed in several directions. These dunes can grow to be over 100 meters high, making them some of the tallest sand dunes in the world.
Parabolic Dunes
Parabolic dunes are a specific type of crescent-shaped dune. They are typically found in areas of desert where the sand is very loose and dry. The shape of a parabolic dune is created when the wind blows the sand into a ridge that curves gently down to the ground on both sides. The dune gets its name from the parabolic shape that is formed when you draw a line connecting the high point of the ridge to the low point on either side.
Barchan Dunes
Barchan dunes are crescent-shaped sand dunes that are found in areas of limited sand supply. They form when the wind blows consistently from one direction, and the sand supply is limited to a point where the dunes can not merge. Barchan dunes have two horns or points that face the wind, and the back of the dune is curved.
Growth and Formation of Dunes
Winds blowing over a sand surface create ripples and waves. These waves move the sand to the lee side (downwind side) of the ripple or wave. This process of sand movement is called deflation. The sand that is moved is then available to be moved by the next wave. This process continues as long as the wind continues to blow.
The sand that is moved to the lee side of the ripple or wave is called the dune. The dune starts as a small ripple or wave. The dune grows as the sand is moved to the lee side. Dune grows faster if the sand is loose. The dune also grows faster if the wind is blowing harder.
The dune continues to grow until it is the same height as the ripple or wave. Dune then starts to erode. The sand that is at the top of the dune is the first to erode. The sand that is at the bottom of the dune is the last to erode.
Sand Dune – About Types.
