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Ocean surface waves are surface waves that occur at the surface of an ocean. They usually result from distant winds or geologic effects and may travel thousands of miles before striking land. They range in size from small ripples to huge tsunamis. There is surprisingly little actual forward motion of individual water particles in a wave, despite the large amount of forward energy it may carry. Image File history File links Download high resolution version (1024x768, 122 KB) Summary Picture of waves from http://pdphoto. ...
Image File history File links Download high resolution version (1024x768, 122 KB) Summary Picture of waves from http://pdphoto. ...
// In physics, a surface wave is, for a mechanical wave, guided along the interface between two differing mediums. ...
The worlds oceans as seen from the South Pacific Ocean Oceans (from Okeanos in Greek, the ancient Greeks noticing the strong current that flowed off Gibraltar and assuming it was a great river) cover almost three quarters (71%) of the surface of the Earth, and nearly half of the...
The tsunami that struck Malé in the Maldives on December 26, 2004. ...
How waves are formed and measured
The great majority of waves one sees on an ocean beach result from distant winds. Three factors influence the formation of "wind waves": - Windspeed
- Length of time the wind has blown over a given area
- Distance of open water that the wind has blown over; called fetch
All of these factors work together to determine the size and shape of ocean waves. The greater each of the variables, the larger the waves. Waves are measured by: Fetch is a term for the length of water over which a given wind has blown. ...
- Height (from trough to crest)
- Length (from crest to crest)
- Steepness, or slope (either the angle between crest and trough, or the "steepness ratio," of the wave's height to its length)
- Period (length of time between crests)
There are theoretical limitations, however, for each variable. The smaller the fetch, the smaller the largest wave can be for a given wind speed, regardless of how long the wind blows. Look up Slope in Wiktionary, the free dictionary The slope or the gradient is commonly used to describe the measurement of the steepness, incline or grade of a straight line. ...
Both in theory and in reality, waves are never created in one uniform height. They fall into a systemic pattern of varying size. For weather reporting and for scientific analysis of wave behavior, their size over a period of time is usually expressed as "significant wave height." This figure represents the average of the highest one-third of the waves in a given time period (usually twelve hours) or in a specific wave or storm system. Given the variability of wave size, it might be expected that individual waves are likely to be twice the reported significant wave height for a particular day or storm.
Types of waves Waves take time to develop; they do not spontaneously erupt from the ocean. It takes a certain speed of wind to blow over a certain distance for a considerable length of time to create lasting waves.
Three different types of waves develop over time:
Ripples appear on smooth water when the wind is light, but die if the wind stops. Seas are created when the wind has blown for a while at a given velocity. They tend to last much longer, even after the wind has died. Swells are waves that have moved away from their area of origin and are unrelated to the local wind conditions. They may be thought of as seas that persist long after the wind that produced them has stopped. Look up swell in Wiktionary, the free dictionary. ...
Some waves undergo a phenomenon called "breaking". A breaking wave is one whose base can no longer support its top, causing it to collapse. A very large breaking wave can impart a pressure of up to 50 to 100 kilopascals (4 to 9 short tons per square yard), enough force to crush the hull of a ship. A wave breaks when it runs into shallow water, or when two wave systems oppose and combine forces. When the slope, or steepness ratio, of a wave is too great, breaking is inevitable. A 1:24 slope may be a long, shallow swell found in deep waters. A 1:14 and higher slope is a wave that is too steep to remain coherent. Waves can also break if the wind grows strong enough to blow the crest off the base of the wave. The wind speed required for this to occur is unpredictable, as it varies as a function of the slope of the wave, as well as the force of gravity, and the density and surface tension of seawater. The pascal (symbol Pa) is the SI unit of pressure. ...
The short ton is a unit of mass equal to 907. ...
There are three main types of waves that are identified by surfers or surf lifesavers. Their varying characteristics make them more or less suitable for surfing, and present different dangers. See World Wide Web for surfing the web; see also Wind surfing Surfing at Kaneohe Bay, Hawaii. ...
This page is on surf lifesaving in Australia; for surf lifesaving in New Zealand, see Surf Life Saving New Zealand. ...
- Spilling, or rolling: these are the safest to surf on; they can be found in relatively sheltered areas.
- Plunging, or dumping: these break suddenly and can "dump" swimmers—pushing them to the bottom with great force. Strong winds can cause dumpers; they can also be found where there is a sudden rise in the sea floor.
- Surging: these may never actually break as they approach the water's edge, as the water below them is very deep. These waves can knock swimmers over and drag them back into deeper water.
Waves can also be classified as either constructive or destructive:  The backwash is weak on a constructive wave while the swash is strong - Constructive waves are usually associated with long fetch.They tend to be low in height (under 1 metre), have a long wavelenth (up to 100 metres) and have a low frequency (around six-eight per minute). As they approach the beach, the wave front steepens only slowly, giving a gently spill on the beach surface. Swash rapidly loses volume and energy as water percolates through the beach material. This tends to give a weak backwash that has insufficient force to pull sediment off the beach or to impede swash from the next wave. As a consequence, material is slowly, but constantly, moved up the beach, leading to the formation of ridges (or berms).
 The backwash is strong on a destructive wave while the Swash is weak - Destructive waves tend to occur when the fetch is shorter. They are tall, toppling waves with a steep form and a high frequency (10–14 per minute). As they approach the beach, they rapidly steepen, and when breaking they plunge down and scour the beach. This creates a powerful backwash, as there is little forward movement of water. It also inhibits the swash from the next wave. Very little material is moved up the beach, leaving the backwash to pull material away. Destructive waves are commonly associated with steeper beach profiles. The force of each wave may project some shingle well towards the rear of the beach where it forms a large ridge known as the storm beach.
This page is a candidate to be copied to Wiktionary. ...
Fetch is a term for the length of water over which a given wind has blown. ...
This page is a candidate to be copied to Wiktionary. ...
Science of waves
 Motion of a particle in a ocean wave. A=At deep water. B=At shallow water (ocean floor is now at B). The circular movement of a surface particle becomes elliptical with decreasing depth. 1= Progression of wave 2= Crest 3= Trough Ocean waves are mechanical waves that propagate along the interface between water and air; the restoring force is provided by gravity, and so they are often referred to as surface gravity waves. As the wind blows, pressure and friction forces perturb the equilibrium of the ocean surface.These forces transfer energy from the air to the water, forming waves. In the case of monochromatic linear plane waves in deep water, particles near the surface move in circular paths, making ocean surface waves a combination of longitudinal (back and forth) and transverse (up and down) wave motions. When waves propagate in shallow water, (where the depth is less than half the wavelength) the particle trajectories are compressed into ellipses. As the wave amplitude (height) increases, the particle paths no longer form closed orbits; rather, after the passage of each crest, particles are displaced a little forward from their previous positions, a phenomenon known as Stokes drift. A good illustration of the wave motion is given by *Prof. Robert Dalrymple Java applet Image File history File links Download high resolution version (2765x2612, 235 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Wave Ocean surface wave Talk:Ocean surface wave ...
Image File history File links Download high resolution version (2765x2612, 235 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Wave Ocean surface wave Talk:Ocean surface wave ...
A wave is a disturbance that propagates through space, often transferring energy. ...
Impact of a drop of water. ...
AIR is a three-letter abbreviation with multiple meanings, as described below: The Annals of Improbable Research, a monthly magazine devoted to scientific humour All India Radio - Indias Government Radio service AIR, a popular electronica band from France. ...
In fluid dynamics, gravity waves are those generated in a fluid medium or on an interface (e. ...
Wind is the roughly horizontal movement of air (as opposed to an air current) caused by uneven heating of the Earths surface. ...
Longitudinal waves, also referred to as compressional waves or pressure waves, are waves that have vibrations along or parallel to their direction of travel. ...
A light wave is an example of a transverse wave. ...
The ellipse and some of its mathematical properties. ...
As the depth into the ocean increases, the radius of the circular motion decreases. By a depth equal to half the wavelength λ, the orbital movement has decayed nearly to zero. The speed of the surface wave is also called celerity as it corresponds to the speed of the shape of the wave, note that this is not directly related to the speed of the water particles. The celerity is well approximated by The wavelength is the distance between repeating units of a wave pattern. ...
Speed (symbol: v) is the rate of motion, or equivalently the rate of change of position, expressed as distance d moved per unit of time t. ...
where - c = phase speed;
- λ = wavelength;
- d = water depth;
- g = acceleration due to gravity;
In deep water, where , so and the hyperbolic tangent approaches 1, c, in m/s, approximates , when λ is measured in meters. This expression tells us that waves of different wavelengths travel at different speeds. The fastest waves in a storm are the ones with the longest wavelength. As a result, when after a storm waves arrive on the coast, the first ones to arrive are the long wavelength swells. The acceleration due to gravity denoted g (also gee) is a non-SI unit of acceleration defined as exactly 9. ...
When several wave trains are present, which is always the case in the ocean, the waves form groups. In deep water the groups travel at a group velocity which is half of the phase velocity.[citation needed] Following a single wave in a group one can see the wave appearing at the back of the group, growing and finally disappearing at the front of the group. The group velocity of a wave is the velocity with which the variations in the shape of the waves amplitude (known as the modulation or envelope of the wave) propagate through space. ...
As the water depth d decreases towards the coast, this will have an effect on the speed of the crest and the trough of the wave; the crest moves faster than the trough. This causes surf, a breaking of the waves. Rugged coastline of the West Coast of New Zealand The coast is defined as the part of the land adjoining or near the ocean. ...
A crest is the section of a wave that rises above an undisturbed position. ...
Look up surf on Wiktionary, the free dictionary. ...
Individual "freak waves" (also "rogue waves", "monster waves" and "king waves") sometimes occur in the ocean, often as high as 30 metres. Such waves are distinct from tides, caused by the moon and sun's pull, tsunamis that are caused by underwater earthquakes or landslides, and waves generated by underwater explosions or the fall of meteorites. The Draupner wave, a single giant wave measured on New Years Day 1995, finally confirmed the existence of freak waves, which had previously been considered near-mythical Freak waves, also known as rogue waves or monster waves, are relatively large and spontaneous ocean surface waves which can sink even...
The metre, or meter (US), is a measure of length. ...
The tide is the cyclic rising and falling of Earths ocean surface caused by the tidal forces of the Moon and the Sun acting on the Earth. ...
Bulk composition of the Moons mantle and crust estimated, weight percent Oxygen 42. ...
The Sun is the star of our solar system. ...
The tsunami that struck Malé in the Maldives on December 26, 2004. ...
An earthquake is a phenomenon that results from and is powered by the sudden release of stored energy that radiates seismic waves. ...
Landslide of soil and regolith in Pakistan A landslide is a geological phenomenon which includes a wide range of ground movement, such as rock falls, deep failure of slopes and shallow debris flows. ...
An underwater explosion, also known as an UNDEX, is an explosion beneath the surface of water. ...
A meteorite is an extraterrestrial body that survives its impact with the Earths surface without being destroyed. ...
The movement of ocean waves can be captured by wave energy devices. The energy density (per unit area) of regular sinusoidal waves depends on the water density ρ, gravity acceleration g and the wave height h (which is equal to twice the amplitude, a): Wave power refers to the energy of ocean surface waves and the capture of that energy to do useful work - including electricity generation, desalination, and the pumping of water (into reservoirs). ...
Density (symbol: Ï - Greek: rho) is a measure of mass per volume. ...
Amplitude is a nonnegative scalar measure of a waves magnitude of oscillation, that is, magnitude of the maximum disturbance in the medium during one wave cycle. ...
The velocity of propagation of this energy is the group velocity. The group velocity of a wave is the velocity with which the variations in the shape of the waves amplitude (known as the modulation or envelope of the wave) propagate through space. ...
Gallery Breaking waves at Children's Pool, in La Jolla, CA. Image File history File links Download high resolution version (1024x768, 153 KB) Source:http://pdphoto. ...
One of the beaches at La Jolla Cove. ...
| A wave just before breaking at Manhattan Beach, CA. Image File history File linksMetadata Download high resolution version (1296x976, 444 KB) Summary A wave in Manhattan beach, Los Angeles County with surfer duck-diving underneath it, photographer Eino Mustonen. ...
The municipal pier in downtown Manhattan Beach. ...
| Waves breaking on rocks. Image File history File linksMetadata Download high resolution version (1600x1200, 773 KB) Summary Taken by User:Cantus in 2006. ...
| Plunging wave or dumper forming a tube. Image File history File links Breaking wave photographed in Brigantine, New Jersey Surf, Glassy, Atlantic Photograph by Ole Kils olekils@web. ...
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See also Artificial waves are man-made waves usually created on a specially designed surface or in a pool. ...
The Beaufort scale is an empirical measure for describing wind intensity based mainly on observed sea conditions. ...
The Draupner wave, a single giant wave measured on New Years Day 1995, finally confirmed the existence of freak waves, which had previously been considered near-mythical Freak waves, also known as rogue waves or monster waves, are relatively large and spontaneous ocean surface waves which can sink even...
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