Decadal Sand Bar Behavior Essay Example | Topics and Well Written Essays - 1000 words

Decadal Sand Bar Behavior - Essay Example Tough availability of the material is of equal importance in forming a sand bar; the size of the material of the Sand Bar depends on the size of the waves or the strength of the material. As a bar is merely a disposition of material by the water, in case of vessel grounding on these bars is worse off than grounding on stationary rocks. This is because of the more destruction caused by the shifting action of these materials. These bars can spread over a considerable range in size and length, from just a couple of meters in a small stream to large depositions stretching over hundreds of kilometres along a coastline, commonly known as barrier islands. Long shore currents or even fluvial currents in the shallow water coastal environments are responsible for the construction of submerged bars. These bars are strongly determined by the amount of unused sediment available along a shore. These sediments along the shore are called its "sand budget" and determine the number of bars that form along the coastline. The types of submerged bars and the orientations and shapes are controlled by the way the sediments are transported through the shore zone. Along the shoreline which is mostly dominated by waves, the shore current carry and deposit the sediments along the shore face in parallel bars to the shore. ... The phenomena of wave refraction and zone interaction are also responsible for creating shore currents that helps the disposition and transportation of sand particles in deep water. Tides also are a major medium of transportation of the sediments; submerged tidal bars which are perpendicular to the coastline are also formed due to these bidirectional tidal currents. There are tidal deltas which are kinds of submerged bars formed on either side of the island inlet due to the tides which transport sand into and out of coast through barrier island inlets. These submerged bars are also formed in places where the rivers enter the ocean. When fresh water from a curbed channel discharges into the ocean having salt water, the current becomes slow and deposit its sediment at the mouth of the river called the channel mouth bar. Many of these different kinds of submerged bars namely long shore bars, channel mouth bars and the tidal bars coexist in a same environment. This is due to the wave action and tidal currents which influence the shore to a great extent. Shore parallel and perpendicular processes create bars with intermediate curved or diagonally oriented structures. These submerged bars characteristically obstruct natural and man-made outlets into the ocean, and are hazards well know to the navigation. Offshore features of a beach include bars that that are formed at or off the shore of a sea or a river. There are times when large waves attack the beach shore-zone and some of the beach's sand is redistributed off the shore resulting in a sandbar or long shore bar. Due to these bars forms the waves start breaking and because these breaking waves set up currents towards the shore with a currents countering along the