Sandbars

 

Sandbars are the long masses or low ridge of submerged or partially exposed sand built up in the water along a shore or beach. Sandbar also known as the offshore bars. Sandbar form due to action of waves and currents. Sandbar begin forming underwater and they are usually formed by sand or coarse sediment deposition offshore from a beach. Large waves can build sandbars far from shore during heavy storms and it build up until they rise above the water’s surface. Sometimes sandbars are formed in between two nearby beaches forming a connection between the two. Due to backwash and the rip currents of the water body, more and more sand deposition can occur. Normally, top part of the sandbar lies below the water level, and still-water level or the half-wave height is the water level under which the sandbars are normally submerged.

Bay-mouth bars are the one form of sandbars and they are formed extending partially or entirely across the mouth of a bay. Bay-head bars occur at the heads of bays and they form short distance from the shoreline. Barrier bars formed from the exposed sandbars that can have formed during the high-tide season, and those barrier bars are separated from the beaches by shallow lagoons cutting off the beach from the open sea. Barrier bars occurs around the coastal plains off the shore but except the regions which have rocky landforms.

Sand, gravel and other sediments can gather underwater in large amount when waves are large, and it leads to block channels and prevent ships and boats from passing. And also continuous wave actions and storms can build a sandbar until it becomes a barrier island, and this barrier island provide protection for the channel and the mainland shore behind.

 

Famous sandbars (Barrier islands)

·       Miami Beach, Florida, USA

·       Bolivar Island, Texas, USA

There are 4 types of sandbars present in various estuaries. They are compound, U-shaped, linear and sidebar.

The water behind the sandbars can form tidal pools, lagoons, salt marshes and other wetlands, and variety of marine life can grow in these areas. And these areas are home for a variety of fish and shellfish.

Sandbars are either completely or partially submerged landforms of sand and silt sediments but most often they are submerged inside the water. When they are visible and above the water, there are more chance to get it submerged inside the water again. Because of that, sometimes sandbars can be dangerous. But sandbars are very important because they provide stability to the beach as they reduce the energy of the waves by breaking them and they prevent the severe erosion.

Sandbars create beautiful locations. Due to their nature they attract a lot of tourists, and eatery & beverages business have boomed in sandbars areas.  And also, those sandbar beaches are prime locations for shootings and beautiful locations in the movies. 

Article by - Tashani Chandrasiri 

References:

https://www.vedantu.com

http://worldlandforms.com

https://researchgate.net