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
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