ocean sea waves

• sea waves are undulation of seawater characterized by well developed crests ands and troughs. Sea waves are defined as “Waves are moving energy travelling along the interface between ocean and atmosphere, often transferring energy from a storm far out at sea over distances of several thousand kilometres”.
• Wave Crest: The highest part of a wave.
• Wave Trough: The lowest part of a wave.
• Wave Height: The vertical distance between the wave trough and the wave crest.
• Wave Length: The distance between two consecutive wave crests or between two consecutive wave troughs.
• Wave Frequency: The number of waves passing a fixed point in a specified period of time.
• Wave Period: The time it takes for two successive crests (one wavelength) to pass a specified point. The wave period is often referenced in seconds, e.g. one wave every 6 seconds.
• Fetch: The uninterrupted area or distance over which the wind blows (in the same direction). The greater the fetch, the greater the wave height.
• Waves in deep water are called as oscillatory waves. In oscillatory waves water particle move in circular orbit and they return very nearly to their original position after the passage of the waves
• Waves of shallow water as called as translatory waves. In translatory waves water particle move forward approximately at the same velocity as the wave form.
• Constructive waves: Long frequency waves approaching shore and beach are constructive in character because they lose volume and energy rapidly while moving up the beach because water percolate in shingles and other beach materials and thus the backwash is weakened. Thus low frequency waves help in building of beaches.
• Destructive waves: on the other hand low frequency waves with low with short wave length and high wave frequency occurring on a more sloping shore are destructive in character because instead of spilling they plunge and generate a powerful backwash which combs down the beach material (removes the beach material and transport them towards the sea).
• Wave refraction results in the formation of littoral or longshore currents which move parallel to the sea coast.
• Wind-driven waves, or surface waves, are created by the friction between wind and surface water.
• Sea Waves may be generated due to large number of factors such as: Atmospheric Circulation and Winds, Movement of fluids of two contrasting densities, Techtronic activities on the sea floor such as faulting, Undersea volcanic eruption, Occurrence of undersea earthquakes
• Corrasion: Waves armed with rock debris of all sizes & shapes charge against the base of the cliffs, & wear them back by corrasion. On-coming currents & tides complete the work by sweeping the eroded material into the sea
• Attrition: The constantly moving waves that transport beach materials such as boulders, pebbles, shingle & fine sand, also hurl these materials against each other until they are broken down into very small pieces.
• Hydraulic action: In their forward surge, waves splashing against the coast may enter joints & crevices in the rocks. The air imprisoned inside is immediately compressed but when the waves retreat, the compress air expands with explosive violence.
• Solution: On limestone coasts, the solvent action of the sea water on calcium carbonate sets up chemical changes in the rocks & disintegration takes place
• Sea cliff: A sea cliff is a steep coastal slope created by the erosive power of waves at its base. In other words, cliffs are vertical or near-vertical walls of rock along a coast.
• Sea Cave: Sea cave is a natural cavity or chamber which develops along the coast due to gradual erosion of rock. Sea caves are more frequently formed in lime stone and chalk rocks as they are enrobed more by solution process. Sea caves are, however, not permanent features as they are destroyed in due course of time.
• Arch: When two caves approach one another from either side of a headland and unite, they form an arch, e.g. the Neddie Eye near Wick, Scotland.
• Sea stacks are nothing but the isolated standing rocks in the sea which were once a part of the cliff. These stacks look will like small islands in the sea.
• Stumps: Small underwater stacks are known as stumps.
• Coves: The elliptical hollows formed in the coastal area alternated by hard and weak rocks are called coves and mini-bays.
• Beach: This is the temporary veneer of rock debris on or along a wave-cut platform. It is by the sea waves that the deposition of rock flour is carried out. Beach, this is accumulation of sand, shingles and pebbles at the coast. It is caused by deposition process of the wave when the swash is stronger than backwash.
• Bar is an elongated deposit of sand, shingle or mud, occurring in the sea, more or less parallel to the shore line and sometimes linked to it. They act as a barrier between the mainland and the sea.
• Barrier bars: ridges of sand up to a km wide and 100 m high that lie parallel to about 13% of the world's coasts
• SPIT: A Spit is a long, narrow ridge of deposited materials that extends from the mainland into the sea.
• Tombolo: Tombolo, this is the spit that connects mainland to the island.
• Lagoon: Sometimes due to deposition of waves and currents, both ends of the bar join to enclose a part of sea water between the coast and the bar. This enclosed part of the sea forms a lake of saline water