What process caused the accumulation of sand that produced the sand dunes?
Answers
Answer:
PLS MARK AS BRAINLIEST IF IT HEL[PS YOU .
Explanation:
How Are Sand Dunes Formed?
For a sand dune to form, the following conditions must be met:
1. Deposition of sand must take place quicker than the obstruction material is eroded to enable build up of sand.
2.There must be abundant supply of sand transported to the beach from longshore drift.
3.There must be a huge range between high and low tides so that when the tide subsides, a large area of land is exposed and can dry out to enable the wind to pick up the sediments.
5.Energy for movement, which is strong winds to transport sand particles. However, dunes can also form underwater in rivers.
6.An obstructer or obstacle, for example, a piece of wood or a rock to allow accumulation of sand. Areas with sparse vegetation tend to form many dunes.
7. Dry climate: Moisture usually causes grains of sand to bond together. Large grains present challenges during wind transportation. Additionally, moisture helps plant growth. Plant growth stabilizes loose sediment and stops its movement.
8.Sand dunes are formed due to the earth’s erosional and depositional forces. The sand that results in the formation of sand dunes is eroded from rocks by physical and chemical processes such as wind and water. The erosion leads to accumulation of sand. Strong winds pick up the sand and transport it (typically slightly above the ground) to another location.
The strong wind transports sand in any of the 3 ways:
Saltation
Here, the sand moves in a turbulent flow or bouncing fashion slightly above the ground. Approximately 95% of sand grains flown by the wind move this way.
Suspension
This is where sand grains are blown high up in the air and later settle. Approximately 1% of sand blown by the wind moves this way.
Creep
This is a process whereby sand grains collide with other grains (gravel or clay) prompting them to move. About 45% of sand movement utilizes this kind of movement.
The moment sand is moving; it won’t stop until it collides with an object (driftwood or rock). The weightiest grains would eventually settle against the object forming a small pump or ridge. Due to the fact that the obstacle slows down the speed of the wind, the lighter sand grains get deposited on the other side of the obstacle. Ultimately, the side facing the wind forms a crest, and the lightest of the grains drop down along the slip face. The rolling of sand continues over time, but the sand dune maintains its shape.