Tsunamis, Are There Actually Waves?

After this wole Japan catastrophe my mind has been all over the place in thoughts and out of curiousity I was wondering if there are actual waves during a tsunami? - I mean all the videos I see are the ones where you see the sea overflowing with great force, but I don't see actual tall waves like "deep impact" type....I know it sounds stupid but thats how I thought tsunamis were like, am I confused?

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  • Anonymous
    9 years ago
    Favorite Answer

    The word tsunami is Japanese for harbor wave. Some tsunamis may reach heights of 100 feet (30 m) or more.

    It can be caused by an underwater earthquake, an underwater landslide, or even by an asteroid or other large body that might crash into the ocean. Sometimes a small underwater quake will trigger a landslide that causes a tsunami.

    Such waves are also called tidal waves because they inundate like high tides. But this isn't just any ordinary wave. It can travel at 500 mph deep under the sea. That doesn't mean that it destroys ships on its way to shore. In fact it passes right under them unnoticed. That's because its height might be only a foot or two. Or it might be noticed and not given any special attention because it seems harmless.

    But the situation changes dramatically when the wave comes closer to shore. As it enters shallow waters, it begins to decelerate and gains height as it becomes compressed. Waves up to 100 feet (30 m) or more in height are possible. Of course, one caused by an asteroid impact could be much higher depending on the asteroid's size. Fortunately such occurrences don't happen as frequently as those caused by earthquakes and underwater landslides.

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  • 9 years ago

    Yes, and no.....

    The displacement of the ocean floor creates a pressure wave that moves through the water from the point of the earthquake. In the open ocean, there is no wave, or perhaps only a very small one - possibly indistinguishable from the waves you would see anyway out in the ocean.

    When that pressure wave encounters a sloping sea floor - one that eventually leads to land in some way, whether to a beach, a cliff or something else, then the hydraulic force that is embodied within the water must go somewhere. Since it cannot go into the seafloor, the pressure wave manifests itself as a physical wave. The eventual height of the wave depends on a lot of things at the specific location where you would be observing it, and is hard to predict. The length of the run up to the beach, say, the depth of the ocean along the run, whether or not there is a bay that funnels all the water together and so on. The pressure force within the water thus transforms into a wave that can be much, much larger than any standard wave on a beach.

    The actual height of the wave is only part of the problem. The other is the enormous volume of water that is forced ashore. N number of gallons of water in a wave that is 20 feet high may be less destructive than 1000 x N gallons in a wave that is only 5 feet high. The more massive the amount of water, the more momentum and energy it has - thus hitting the shore/buildings/cars/people with much more force.

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  • 9 years ago

    The waves you see on any day at the sea side are caused by the wind. These waves are on the surface of the sea and their extent is felt little more than the depth of the wave. Ten metres below the wave, there is no sign of it.

    Tsunamis are different. An underwater earthquake of the right sort creates a wave through the entire depth of the water and this wave travels very fast indeed. On the surface in the deep ocean, the wave can hardly be recognised but as the sea bottom shoals towards the land so the wave starts to pile up the water just as Roger K and others have described.

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  • Anonymous
    9 years ago

    A tsunami isn't exactly a wave. It is literally the entire sea rising up because of an earth quake, like twenty, thirty, or more feet and rushing inland for several minutes causing total devastation. It is like an endless wave. There are little waves on top of the tsunami though.

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  • retha
    Lv 4
    4 years ago

    A tsunami is a protracted severe sea wave led to via an earthquake, submarine landslide, or different disturbances. A tidal wave is an exceptionally great ocean wave, quite one led to via an underwater earthquake or volcanic eruption. In a fashion the two are distinctive , yet tidal waves are recent in tsunamis. additionally tidal wave is easily a nontechnical term for a tsunami

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  • 9 years ago

    A tsunami is a massive wave. I don't see what else you can say, really...

    Source(s): Moi.
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  • 9 years ago

    its one huge wave that moves across land because of an earthquake that happened under the ocean

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