47 Interesting Tsunami Facts

by Sankalan Baidya
50 Interesting Tsunami Facts

One of the deadliest forces of nature is the Tsunami. Tsunamis have the ability to destroy almost everything that comes in their way. Unlike the volcanoes where fire, heat, magma and volcanic ash causes destruction, Tsunamis unleash the wrath of water. Yes, the same elements of nature that support life on Earth. Today, let us learn 47 interesting tsunami facts and understand how they work and what they are capable of.

Interesting Tsunami Facts: 1-10

1. Usually an earthquake is responsible for a Tsunami however, it can also be caused by rapid and erratic changes in atmospheric pressure and even by volcanic eruptions. Thus, a tsunami is not a standalone phenomenon. It is usually a byproduct of some other natural force.

2. While some people think that tsunami is a single big wave of water, it is not true. In fact, tsunami is composed of a series of waves, which is referred to as a ‘wave train‘. It is this wave train that causes repeated destruction, making tsunamis extremely dangerous.

3. Low-lying coastal areas are usually the worst-hit areas when a tsunami strikes. Damage is usually contained within 250 km or 160 miles from the point of origin of a tsunami. Destruction befalls within 30 minutes from the time when the tsunami originates. If an earthquake is felt in a coastal area, it should be taken as a sign of an incoming tsunami.

4. Apart from volcanoes, earthquakes, and changes in atmospheric pressure, tsunamis can also be caused by a meteor impact on oceans. Meteor impacts can lead to some of the deadliest tsunamis with waves as high as 100 feet. Sometimes massive landslides can cause tsunamis.

5. The Ring of Fire in the Pacific Ocean is the most active zone for tsunamis. Nearly 80% of all tsunamis all around the world are from that region.

6. Nearly 99% of tsunami fatalities take place within 160 miles from the point of tsunami origin.

7. Underwater earthquakes will not always cause tsunamis. There are two types of underwater earthquakes. First is when two tectonic plates either slide against each other or split apart and the second one is when a lighter tectonic plate is forced above a heavier tectonic plate. The zone where this second type of tectonic plates movement takes place is known as subduction zone. This second type of tectonic plates movement leads to tsunami.

8. When a heavier tectonic plate moves underneath a lighter plate, the entire water column right above the subduction zone is displaced and causes tsunami.

9. Tsunamis are very frequent in the deepest parts of the oceans. However, those deep ocean tsunami waves are usually 1-3 feet tall and usually go unnoticed. Sailors may not even realize that tsunami waves are traveling beneath them.

10. The idea that tsunamis are caused by underwater earthquakes was first proposed by Thucydides in his book, ‘History of the Peloponnesian War’. Thucydides was a Greek historian who lived ca. 460-395 BCE.

Interesting Tsunami Facts: 11-20

11. Tsunamis caused by meteorites have never been witnessed by anyone. However, many scientists believe that 3.5 billion years ago the tsunami that wiped out life from Earth was caused by a giant meteor.

12. Around 4800 years ago, a giant asteroid had hit the Indian Ocean and resulted in a tsunami. Scientists theorize that the resulting waves reached the height of 600 feet or 180 meters high.

13. Winds can generate waves that travel at a speed anywhere between 2 and 60 miles an hour. Tsunami waves on other hand are much faster. They can travel at a speed of 600 miles an hour, which is equivalent to the speed of a usual jet plane.

14. The commonest jargon associated with tsunamis are run-up and inundation. Run-up is vertically the highest point water is capable of reaching during a tsunami. Inundation on the other hand the farthest distance inland where water can reach during tsunamis.

15. In 1960 on May 22, a 9.5 magnitude earthquake shook the earth some 100 miles off the coast of Chile. The resulting tsunami was devastating with 80-foot waves hitting the coast in just 15 minutes after the earthquake. The waves reached Hawaii some 15 hours later. 22 hours later, the waves had traveled 10,000 miles from the point of the earthquake and hit Japan.

16. Yet another deadly tsunami took place in Indian Ocean in 2004 and left behind a death toll of 216,000 confirmed. Some sources quoted the death toll to be 283,000. It was a result of Sumatra-Andaman earthquake where the Burma tectonic plate subducted the Indian tectonic plate

17. The 2004 Indian Ocean Tsunami is dubbed as one of the deadliest tsunamis in recorded history. 14 countries were hit with Indonesia taking the hardest hit of all followed by Sri Lanka, India and Thailand.

18. Boxing Day tsunami, Christmas tsunami, Indonesian tsunami, South Asian tsunami are the four other names of the 2004 Indian Ocean tsunami.

19. Palm trees are the most tsunami-safe trees on Earth. With their long bare trunks, they are adapted to coastal life and mostly survive tsunamis intact.

20. There is something megatsunami. Megatsunamis are caused by massive landslides and the tsunami waves can grow extremely tall. The last mega-tsunami recorded was in 1958 in Alaska’s Lituya Bay with waves touch the record height of 1,700 feet or 534 meters. Weirdly enough, only two people died in that tsunami.

Interesting Tsunami Facts: 21-30

21. It is the [highlight]second tsunami wave that kills most[/highlight]. Once the first wave subsides, people often rush back to their homes or to the shores to save stranded animals and people. But, before they can carry others to safety, the second wave hits with greater power and engulfs the rescuers.

22. When a tsunami crashes on the coastal area, it is not a good idea to swim. It is always good to grab on to a floating object and allow the waves to carry you with the current.

23. Not always but sometimes about 30 minutes before a tsunami strikes, the ocean water appears to be draining away from the shore. This withdrawal of water from the shore is known as ‘drawback’. A drawback implies that tsunami will reach the shoreline.

24. Coming back to the Indian Ocean tsunami of 2004, most of the casualties were women and children. It is being said that the women were waiting at the shoreline for their husbands to come back from fishing and the children were just too weak to survive the currents.

25. On one hand the 2004 Indian Ocean tsunami brought down massive destruction and on the other hand, it also uncovered Mahabalipuram, a lost city. It was the capital city of a very powerful kingdom some 1500 years ago. Back then the city was involved in trade with Egypt, Roma, Arabia, Greece, and China.

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26. When tsunami waves crash on the shore, the speed of the waves is significantly reduced. The waves close to the shore usually travel at a speed of 22 miles an hour. Once the waves crash, the speed at which the water travels inland depends on several factors like beach slope and shore environment.

27. The low speed of the tsunami waves near the shallow shores is also the reason why the waves grow tall. The waves behind travel at a high speed but the slower waves on the front eventually restrict the speed of the waves behind and force them to pile up and grow taller.

28. Once the water from a tsunami travels as far inland as possible, it then backwashes into the ocean. The speed of the backwash may be as fast as the inbound flow of water or may be faster or slower.

29. The aftermath of a tsunami is even worse. The sea water that comes inland ends up poisoning groundwater and freshwater systems with large amount of salt deposits. The debris and the dead bodies floating around can quickly spread diseases and lead to an epidemic.

30. The Indian Ocean tsunami did not manage to kill many animals. It is reported that hours before the tsunami had hit, flamingos and elephants were seen moving up to higher grounds and that caged zoo animals as well as dogs refused to come out of their shelters.

Interesting Tsunami Facts: 31-40

31. The reason why tsunami waves are so powerful is that unlike the regular waves caused by wind on the water surface, tsunami is caused by entire water column being displaced. This gives far more power to tsunami compared to normal waves.

32. Also, looks-wise the tsunami waves are different. They don’t curl and break as normal waves. Tsunami moves in in form of a fast flood or in form of a bore and looks live a wall of water approaching the shore.

33. Tsunamis were once referred to as tidal waves but that was wrong because tsunamis have nothing to do with tides.

34. Over last 2000 years, nearly 500,000 people have died because of tsunamis in the Pacific region alone. Compared to this, the 2004 Indian Ocean tsunami alone killed nearly 280,000 people. No wonder, it was dubbed as the worst tsunami in recorded history.

35. Many geologists argue that ancient tsunamis have given birth to many legends as we know today. For instance, the great Biblical flood, destruction of Minoan Civilization on island of Crete and the Red Sea’s parting during the exodus of Israelites from Egypt.

36. Japan holds the record of hosting the most devastating tsunamis in world. Japan is also the most tsunami-prone country in this world.

37. Because of the frequent tsunamis, Japan has deployed world’s most advanced tsunami warning system that involves 500 water-level gauges and 1,500 seismometers. Money spent for maintaining the system is worth over 20 million US Dollars every year.

Interesting Tsunami Facts: 38-47

38. On March 25, 2011, Japan was hit by a massive tsunami caused by an earthquake which was the fifth most powerful earthquake since 1990. Last time an earthquake of that magnitude had struck the tectonic plate at the boundary of Japan was 1,200 years ago.

39. The 2011 Japan tsunami left behind 10,000 confirmed deaths and 17,440 missings. It was also dubbed as the world’s most expensive disaster in human history. The tsunami damaged the primary cooling systems as well as the generators of the Fukushima Daiichi nuclear complex of Japan.

40. There is something known as teletsunami or transoceanic tsunami. This is a tsunami that is capable of traveling thousands of miles across the ocean without losing much of its energy. As opposed to a transoceanic tsunami, a local tsunami is capable of reaching only to the nearest coast from point of its origin.

41. Europe has to date (at least in recorded history) experienced only two large tsunamis. One was in 1530 BCE that had struck Crete and the surrounding Mediterranean coasts and the other was in 1755 CE. In 1755 it was Lisbon in Portugal that was hit.

42. The 1755 Lisbon tsunami was a classic case of ‘drawback’ tsunami. After a major earthquake, the terrorized citizens rushed to the shorelines for safety. They saw that the water drained away from the shore and were pretty amazed but only minutes later, a devastating tsunami arrived and claimed the lives of 90,000 people.

43. In Japanese, tsunami means ‘harbor wave’. In Japanese language tsu means harbor and nami means wave.

44. The earthquake that cause the 2004 Indian Ocean tsunami released an energy equivalent to 23,000 atomic bombs.

45. In 1963 another megatsunami was recorded, which was also caused by a massive landslide from Monte Toc. The landslide went into Italy’s Vajont Dam resulting in a wave that overtopped the 860 ft high dam by 820 ft. The water that crossed the dam went on to destroy many towns and leaving trail of 2,000 dead bodies.

46. Scientists assume that Canary Islands will be the site for next megatsunami and that the megatsunami will travel across Atlantic and destroy many coastal cities of USA which include Miami, Boston and New York.

An illustration of the rhythmic “drawback” of surface water associated with a wave. It follows that a very large drawback may herald the arrival of a very large wave.

47. A wave typically has a negative peak (trough) and a positive peak (ridge). For propagating waves like tsunami either a trough or a ridge will first reach the shore. If trough reaches first, there will be a drawback, and water will appear to drain out. If the ridge reaches the shore first, there will be sudden flooding or a massive breaking wave.

Sources: 1, 2, 3

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1 comment

TANNERBRAUNGARDT GAVINMAY April 13, 2017 - 8:38 pm



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