By Tasha Stones
A series of great sea waves generated by sudden underwater disturbances that displace a large volume of water mass from its equilibrium position is referred to as a tsunami. Tsunamis typically occur in oceans and seas but can occur in large lakes as well. Tsunami is not just one wave but the so-called "a wave train" - a series of waves that can be as long as 60 miles which may even sounds like a freight train.
Tsunamis are most often triggered by massive changes to the sea floor. Earthquakes, volcanic eruptions, landslides, explosions, underwater nuclear tests and, more rarely, impacts of cosmic bodies, such as meteorites or asteroids, i.e. any disturbance above or below the sea floor, have the potential to generate a tsunami. This usually happens when the sea floor abruptly deforms. The water above the deformed area is displaced from its equilibrium position and may cause the sea to rise vertically as high as 100 feet (30 meters). Tectonic earthquakes are a typical kind of underwater disturbance that displaces the overlying water mass which, under the influence of gravity, tends to regain its balance. This unexpected movement of the water creates a series of powerful waves. Subduction earthquakes are vertical movements of the earth's crust at plate boundaries and the slipping of oceanic plates under continental plates may also trigger a tsunami. Large earthquakes are often followed by submarine landslides that can disturb the overlaying water, too. Tsunamis may also be generated by submarine volcanic eruptions as well as by collapses of volcanic edifices. Underwater nuclear testing can trigger tsunamis but underground testing can trigger them as well. Unlike these, supermarine landslides and cosmic body impacts disturb the water from above. However, the tsunamis generated this way dissipate quickly and rarely affect coastlines distant from the source area.
Tsunamis generated in the deep ocean can sometimes be unnoticed on the surface. They can cross an entire ocean in a single day at speeds up to 500 mph (800 kmph) without losing much energy. Once a tsunami reaches the shore, its power is devastating. The Indian Ocean tsunami in 2004 is said to have a devastating power of 23,000 atomic bombs. However, the first wave may not be the most dangerous. The waves can be several minutes to an hour apart and the danger from a tsunami can last for several hours after the arrival of the first wave.
Tsunamis are most often triggered by massive changes to the sea floor. Earthquakes, volcanic eruptions, landslides, explosions, underwater nuclear tests and, more rarely, impacts of cosmic bodies, such as meteorites or asteroids, i.e. any disturbance above or below the sea floor, have the potential to generate a tsunami. This usually happens when the sea floor abruptly deforms. The water above the deformed area is displaced from its equilibrium position and may cause the sea to rise vertically as high as 100 feet (30 meters). Tectonic earthquakes are a typical kind of underwater disturbance that displaces the overlying water mass which, under the influence of gravity, tends to regain its balance. This unexpected movement of the water creates a series of powerful waves. Subduction earthquakes are vertical movements of the earth's crust at plate boundaries and the slipping of oceanic plates under continental plates may also trigger a tsunami. Large earthquakes are often followed by submarine landslides that can disturb the overlaying water, too. Tsunamis may also be generated by submarine volcanic eruptions as well as by collapses of volcanic edifices. Underwater nuclear testing can trigger tsunamis but underground testing can trigger them as well. Unlike these, supermarine landslides and cosmic body impacts disturb the water from above. However, the tsunamis generated this way dissipate quickly and rarely affect coastlines distant from the source area.
Tsunamis generated in the deep ocean can sometimes be unnoticed on the surface. They can cross an entire ocean in a single day at speeds up to 500 mph (800 kmph) without losing much energy. Once a tsunami reaches the shore, its power is devastating. The Indian Ocean tsunami in 2004 is said to have a devastating power of 23,000 atomic bombs. However, the first wave may not be the most dangerous. The waves can be several minutes to an hour apart and the danger from a tsunami can last for several hours after the arrival of the first wave.
