What causes ocean tides?
99164
The moon causes the tides.  When it is overhead and when it is underneath.  The Sun also causes tides, but it is a smaller effect.  When the Sun and Moon line up, the tides are stronger, and when they are on opposite sides of the earth the tides tend to cancel out and are smaller.\n\nTides also depend a lot on the shape of the ocean floor near the shore (is it shalow or deep, etc.)
518817
lunar activity couses the tides with the gravitational pull
14381
Oceanic tides are caused by the gravitational attraction of the moon which raises up the ocean water beneath the moon causing a high tide.  On the opposite side of the earth there is another high tide bulge caused in part by the spin of the earth.  On the coast we observe two high and two low tides each day.  As the earth spins the tidal bulge approaches a coast.  The shape of the coast affects the height of the tide.  At the Bay of Fundy in eastern Canada, the tide can equal about 45 feet at times because the tide is pulled into a converging channel that amplifies the tide.  On other coasts, for example Caribbean islands, there is very little tide.  Because the gravitational force of the sun also produces a lesser tide than the moon, the sun and moon work together or against each other in a complex way to vary the height of tides as the earth rotates about the sun in a less than perfect circle and the moon rotates about the earth and the earth spins on its axis.  The angle of the earth's axis relative to the sun changes with the seasons also affecting heights of tides below the sun. \n\nTherefore at selected coastal stations, the tides are measured over long periods ot time in special hollow tubes  with measuring scales (that are not affected by waves) and statistics are collected to predict future tides relative to the positions of the sun and moon.  These data can be extrapolated or interpolated to prepare tide tables for nearby coastal areas that do not have their own measuring tubes.
1159551
The moons gravitational pull does cause the tides, the sun to a lesser extent also exerts a pull.  When the sun and the moon are on the same side of the earth the tidal pull is the greatest, when on the opposite they are the least.
178742
Good question!\n\nIn fact, causing the tide on Earth actually results in the Earth-Moon system losing a little energy during every orbit.  \n\nThis results in the moon moving a little further from the earth to maintain the angular momentum of the system.
965180
Tsunamis are caused by an underwater earthquake, a volcanic eruption, an sub-marine rockslide, or, more rarely, by an asteroid or meteoroid crashing into in the water from space. Most tsunamis are caused by underwater earthquakes, but not all underwater earthquakes cause tsunamis - an earthquake has to be over about magnitude 6.75 on the Richter scale for it to cause a tsunami. About 90 percent of all tsunamis occur in the Pacific Ocean.
104328
Obviously English is not your first language, but you make yourself perfectly understood - ignore people like Zinger.\n\nThe Earth's tides are caused by a combination of the moon's gravity and the gravitational effects of our own orbit around the sun, so I would imagine that we will have tides for as long as the moon and sun are around.
59019
Tides are periodic rises and falls of large bodies of water. Tides are caused by the gravitational interaction between the Earth and the Moon. The gravitational attraction of the moon causes the oceans to bulge out in the direction of the moon. Another bulge occurs on the opposite side, since the Earth is also being pulled toward the moon (and away from the water on the far side). Since the earth is rotating while this is happening, two tides occur each day. \n\nIsaac Newton (1642 -1727) was the first person to explain tides scientifically. His explanation of the tides (and many other phenomena) was published in 1686, in the second volume of the Principia.
147245
Actually only about 2/3 of the tides are from the moon's gravity, and about 1/3 are from the sun's gravity. \n\nThe reason there are about 2 high tides per day, is that the gravity field produced by the sun and the moon is not constant. The farther away from the moon you are, the less the gravity is. So water close to the moon gets pulled away from the earth (the force on the earth is less since the earth is farther away) and it gets pulled up in a pile we call a high tide. On the other side of the earth, the earth is pulled away from the water (since the earth is closer to the moon than the water on that side of the earth), leaving a pile of water on the far side of the earth, which is the other high tide. \n\nIn between these two piles of water, there are places where the water is not getting piled up. We say those places are experiencing a low tide. \n\nIt gets much more complicated than this of course. There are tides in the ground and in the atmosphere, in lakes and in rivers etc. There are places where there is one high tide a day or 3 or more or even no high tides per day (because of the response of the local area to the tidal forcing; governed by the bottom topography, coastline shape, etc). \n\nThere are high tides that are extra high because the sun and the moon line up (spring tides) and high tides that are not so high because the sun and the moon are at right angles, not working together (neap tides). There are ultra high tides when the moon is especially close (proxigean spring tides). There are effects of the other planets like Jupiter   and Mars in the tides. And so on.
564925
Moon AFFECTS the earth on whole, the effect of it is the tilt in earth's axis. And the tide is because the water is not exactly fixed with the surface of earth and it gets attracted towards moon. We could have also seen a 'land tide' but bcoz it is solid it is more firmly fixed to earth.
1163669
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
265966
Waves are normally created by wind!\n\nAdditionally, just like the earth, even the moon has gravity... Its the moon's gravity that pulls the sea water towards it, and "creates" waves!
108928
The concepts of ebb and flow has a lot of contexts. Strictly speaking, the incoming tide is called a flow and the outgoing is called the ebb.\n\nTides on earth are caused by gravitional attraction with primarily the moon and to a lesser degree the sun. Water attracted to the moon is raised above the mean tidal level much like a bulge and the earth spins underneath this bulge. High tide corresponds to the highest point of the this tidal bulge and low tide is roughly 12 hours opposite.
17074
The moons gravity is what causes ocean waves. It affects big bodies of water such as oceans or seas but as for water in a toilet I highly doubt because if you think about it, the moon's gravity doesn't effect pond water. The only thing that would affect toilet water is water pressure, and on the global scale the Corriolis Effect. But that only effects the direction of the water when flushed. So the most probable cause is the water pressure of your city.
603269
The tide is governed by the motions of the Moon orbiting Earth, and Earth orbiting the Sun, Each of which has a gravitational influence on the Earth. When the Moon and Sun are in line, (ie) new Moon, the tides are higher than usual.Then, when you take into account the geographical situations along coast lines, like gulfs, inlets, etc. the tidal effects can be more pronounced.
221565
TIDAL ENERGY \n\nTides are caused by the gravitational attraction of the moon and the sun acting upon the oceans of the rotating earth. The relative motions of these bodies cause the surface of the oceans to be raised and lowered periodically, according to a number of interacting cycles. These include: \n\na half day cycle, due to the rotation of the earth within the gravitational field of the moon \n\na 14 day cycle, resulting from the gravitational field of the moon combining with that of the sun to give alternating spring (maximum) and neap (minimum) tides \n\na half year cycle, due to the inclination of the moon's orbit to that of the earth, giving rise to maxima in the spring tides in March and September \n\nother cycles, such as those over 19 years and 1 600 years, arising from further complex gravitational interactions. \n\nThe amount of energy obtainable from a tidal energy scheme therefore varies with location and time. Output changes as the tide ebbs and floods each day; it can also vary by a factor of about four over a spring-neap cycle. Tidal energy is, however, highly predictable in both amount and timing.
1014431
Tides are more complex than people think.   Tides are like the "modes" of a standing wave which is driven by two main forcing mechanisms - the moon's relative orbit (twelve and a bit hours) and the earth's spin relative to the sun (twenty four hours).  Those are the "fundamental" frequencies but there are  harmonics on top of those.  The lunar tides are referred to as M0, M1, etc.   M0 is the biggie that we're all aware of.   M1 and so on take a bit more effort to detect but they're all there if you look hard enough.   Then you take all that mathematical soup and force it to interact with uneven bathymetry (sea bed shape) and it all gets very weird.   But utterly predictable.