What Makes Sand Dunes Shaped Asymmetrically?
What makes sand dunes shaped asymmetrically? And what is the main factor? Read on to learn more.
In this article, we will look at the factors that determine dune formation and learn what they are. And, as a bonus, you’ll learn why certain dunes are asymmetric. Here’s an illustration. Hopefully, you will get a better idea of how these dunes came to be.
What determines the shape of a sand dune?
The shape of sand dunes depends on the strength of wind and the direction of the wind. Wind moves individual grains up an inclined windward surface and down a steep leeward side.
This results in a small bump. Lighter grains are carried along with the wind and deposit on the other side of the dune. Sand dune shapes continue to change over time.
Dunes can be of three types. Simple dunes are isolated ridges of sand. These dunes tend to have a minimum number of slipfaces, while compound dunes are larger dune fields with smaller ones superimposed.
In some cases, two or more types of dune are combined to form one larger, irregularly-shaped mound. The shape of the dune field is dependent on the type of wind, but the most common form is a U or V-shaped dune.
Why do sand dunes have different shapes?
The shapes of sand dunes are determined by the winds and sand supply. Sand dunes are classified by names, but each type has basic characteristics.
To understand the shape of the sand dunes in your region, you can refer to the books by Pye, Tsoar, and Lancaster. Both books are full of information. To understand the differences in dunes, you should first know how to recognize them.
In a natural setting, the wind creates a layering effect in the sand. This layering process is known as slip face movement. The leading edge of the dune rises due to the wind, while the other side slides down. Eventually, the sand mound has a steep slope. The top surface of the dune is called the stoss face, and the bottom is called the slip face.
What is the most important factor for dune formation?
To understand the processes that lead to asymmetrical sand dunes, we need to know more about their morphology. We have previously studied the relationship between dune roughness and net bed load transport.
Here, we examine the morphological state of asymmetrical dunes, and we consider the effects of two important factors: tidal regime and dune roughness.
Wind is one of the key factors in determining dune movement and shape. The direction of wind is the most important factor in determining asymmetrical sand dunes, but this is difficult to quantify without field measurements.
According to Scuderi et al., the wind regimes are bimodal, which means that bedforms are aligned transverse to the wind direction.