This name is misleading, because tsunamis are not related to tides ; they merely rise slowly as a series of fast-moving waves in the ocean caused by powerful earthquakes or volcanic eruptions. The deadliest tsunami recorded in documented history was on 26 December , and is known as the Indian Ocean Tsunami.
It was caused by an earthquake. The earthquake was said to have a magnitude of 9. It was centered in the ocean near the coast of Sumatra , Indonesia.
Over , people, mainly on the shores of the Indian Ocean , died from this disaster. The giant wave moved very quickly. Thousands of people in Indonesia , Sri Lanka , Thailand , India , Somalia , and other nations, were killed or injured by it. It went a huge distance in inland, and is also the 4th largest tsunami in history. There is another type of tsunami known as a megatsunami, which is mainly due to external impact on the ocean, like an asteroid or meteor crash, a landslide, a rockslide etc.
While Japan may have the longest recorded history of tsunamis, the sheer destruction caused by the Indian Ocean earthquake and tsunami event mark it as the most devastating of its kind in modern times, killing around , people. The Sumatran region is also accustomed to tsunamis, with earthquakes of varying magnitudes regularly occurring off the coast of the island. Of historical and current importance are the Lisbon earthquake and tsunami which was caused by the Azores—Gibraltar Transform Fault , the Calabrian earthquakes, each causing several tens of thousands of deaths and the Messina earthquake and tsunami.
The tsunami claimed more than , lives in Sicily and Calabria and is among the most deadly natural disasters in modern Europe. The Storegga Slide in the Norwegian Sea and some examples of tsunamis affecting the British Isles refer to landslide and meteotsunamis predominantly and less to earthquake-induced waves. As early as BC the Greek historian Thucydides inquired in his book History of the Peloponnesian War about the causes of tsunami, and was the first to argue that ocean earthquakes must be the cause.
The waves are likely generated by associated landslides or motion of a sloping bathymetric feature. Tsunamis generated by strike-slip earthquakes normally affect regions near the source only. Tsunami soo-NAH-mee is a Japanese word meaning harbor wave. How fast do tsunamis travel? Tsunami velocity depends on the depth of water through which it travels. Velocity equals the square root of the product of the water depth times the acceleration of gravity.
Tsunamis travel approximately mph in 15, feet of water. In feet of water the velocity drops to about 40 mph. Did you know…A tsunami travels from the central Aleutian Islands to Hawaii in about 5 hours and to California in about 6 hours, or from the Portugal coast to North Carolina in about 8. How big is a tsunami? Tsunamis range in size from inches to over a hundred feet.
In deep water greater than feet , tsunamis are rarely over 3 feet and are not normally noticed by ships due to their long period or time between crests.
As tsunamis propagate into shallow water, the wave height can increase by over 10 times. Tsunami heights vary greatly along a coast. The waves can be amplified by shoreline and sea floor features. A large tsunami can flood low-lying coastal land over a mile from the coast. What does a tsunami look like when it reaches shore?
Normally, a tsunami appears as a rapidly advancing or receding tide. Because of this, their arrival can often be calculated. How big do you think a normal wave gets at a beach? Well it is normally about 3 foot 1 meter high. Now a tsunami wave can reach a height of feet But the highest recorded one was the Lituya Bay, Alaska Megatsunami with a recorded height of 1, feet meters. The Asian Tsunami in in the Indian Ocean is considered the deadliest Tsunami ever, which was caused by an earthquake with the energy of 23, atomic bombs!
This brought with it incredibly destructive waves hitting the coastlines of eleven countries from Thailand to Africa, killing , people and wiping out cities. The power of the water picks up aeroplanes, ships, houses and anything in its path and tosses them around like corks. People can see the ocean floor littered with flopping fish and other sea animals. Then a wave blasts onto the shore minutes later, then another and another for two hours or more. There may also be up to one hour between each wave.
Its network of detectors can track quakes that may cause a tsunami. These waves can race from one side of the Pacific Ocean to the other in less than a day, so people need to be warned in time to head for higher ground! While you wait for it to be checked and approved why not to add a pre-selected message and a cool badge.
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