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Tsunami Facts

Abhay Burande Oct 16, 2020
The devastating tsunamis of 2004 and 2011 have made this calamity a truly feared one. Capable of killing thousands in the matter of a few seconds, tsunamis have struck fear into all, but more so to those living in coastal regions.

Did You Know?

In 2004, a 9.1 magnitude earthquake in the Indian Ocean generated a tsunami with waves reaching a height of 9 meters, hitting the coasts of 11 Indian Ocean countries, causing widespread devastation ranging from Thailand to Africa.
When a large body of water is rapidly displaced, a series of waves are created. This series of waves is collectively called a 'tsunami'.
This rapid displacement of water can take place due to various reasons such as volcanic eruptions, underwater landslides, earthquakes, underwater explosions, large meteorite impacts, mass movements above or under water, nuclear weapons, and testing in the seas.
Tsunamis are dangerous, devastating, and can cause great harm to life and property alike. With so many lives lost, not to mention the financial losses for nations, we should be thankful that tsunamis are so few and far in between. The following tsunami facts show us how much destruction these giant waves cause in their wake.

A Few Facts About Tsunamis

-Tsunami is a Japanese word. 'Tsu' translates to harbor, and 'nami' to wave.
The first description of a tsunami was recorded by the Greek historian, Thucydides, in his book 'History of the Peloponnesian Wars', way back in 400 B.C.
Tsunamis are, in most cases, preceded by underwater earthquakes. Earthquakes near large bodies of water can also be capable of generating tsunamis.
If the water along the shoreline recedes dramatically and exposes usually submerged areas, it should be inferred that it is the trough of the tsunami (also called drawback) and the crest will follow after a few seconds or minutes.
It is an astonishing fact that sometimes, tsunami waves are an hour apart and as long as 60 miles. The time between two tsunami waves is called a 'wave period'.
A tsunami is accompanied by a loud roar, similar to a train or an aircraft. It is said that tsunamis can travel across oceans with a speed of about 500 miles/hr. This means, they travel approximately as fast as a jet airplane.
Many countries like Japan build tsunami walls up to 12 meters high in populated coastal areas. Floodgates and channels are also built to redirect the water from the tsunami. Although these measures slow down and moderate a tsunami, they cannot totally prevent the destruction and loss of life.
It is often rumored that some large animals like elephants, and birds like flamingos, can hear the noise or feel a tsunami coming, and move in the opposite direction, i.e. towards land.
According to the US National Oceanic and Atmospheric Administration (NOAA), the Pacific Ocean happens to be the most active tsunami zone.
Alaska, Oregon, California, Hawaii, and Washington are the most tsunami prone areas in the United States.
Hawaii is said to experience at least one tsunami a year. Also, every seven years, it sees one damaging tsunami.
It is more advisable to run on foot and find an elevated point to keep yourself safe from the waves of a tsunami, rather than to drive a car and get stuck in traffic.
If caught in a tsunami, rather than trying to swim, it is advised to hold on to a floating object and let the waves carry you along.
Tsunami waves are different from normal waves as they show no signs of curling or breaking. They come along as flood water.
A 'megatsunami' is caused by large landslides. The displaced water mass moves under the effect of gravity. In 1958, a megatsunami occurred with waves reaching a height of 1700 feet in Alaska. Yet astonishingly, only two people died.
A megatsunami is also called 'iminami' or 'wave of purification'.

Damage Caused by Tsunamis

The earthquake of 2004 in Indonesia displaced a large segment of land under the ocean, leading to a massive tsunami in which 141,000 houses were destroyed.
According to WHO reports, the financial loss was estimated to be 9.9 billion US dollars. Along with natives, thousand of tourists were killed in the 2004 tsunami.
During the Tohoku earthquake in 2011, tsunami waves reached 131 feet and caused nuclear accidents. They also completely wiped out coastal towns. The tsunami caused losses of 235 billion dollars, and it will take Japan two years more to recover from the loss.
It was also the biggest tsunami in Japan and the fourth-largest tsunami in the world. The quake which preceded the 2011 tsunami lasted for six minutes. The resulting tsunami caused around 190,000 buildings to collapse.
In 2010, the Sumatran earthquake/tsunami killed around 500 people and displaced around 20,000 people.
The eruption of a volcano in western Japan caused a megatsunami in 1792, with waves reaching a height of 330 feet and killing more than 15,000 people.
The after effects of tsunamis can be very harmful as it adds a large amount of salt to the normal drinking water, proving to be hazardous to human health.
During the 1960 Valdivia earthquake, tsunami waves were recorded 10,000 miles away from the epicenter. This also happens to be the most powerful earthquake till date. On the moment magnitude scale, it was rated 9.5.

Three of the World's Deadliest Tsunamis

Also known as Boxing Day tsunami, this disastrous tsunami occurred on December 26, 2004, caused by a 9.1 earthquake in the Indian ocean.
The Indian Ocean Tsunami, 2004
Being the third-largest quake recorded on a seismograph, it triggered a tsunami with waves reaching a height of 50 meters. Indonesia was the hardest-hit country. The quake and the tsunami together claimed between 200,000 to 300,000 lives. It is said that this earthquake affected the entire planet in one way or another.
The second-most disastrous tsunami was reported in Messina in Sicily, southern Italy. On Dec 28, an earthquake with a magnitude of 7.1 occurred, which caused a tsunami with waves around 12 meters high.
The Messina Earthquake, 1908
The double catastrophe completely destroyed most of Messina and the nearby coastal areas. Around 40% of Messina perished to this calamity and the incident accounted for the total death of around 100,000 - 200,000 people.
The third-deadliest tsunami occurred following an earthquake in Portugal on November 1, 1755.
The Lisbon Earthquake, 1755
The magnitude of the earthquake was recorded to be around 8.5 to 9.0 on the Richter scale with an epicenter in the Atlantic ocean. After 40 minutes, the quake set off a tsunami, with waves rising 15 meters, claiming around 100,000 lives.
Technology has helped in developing international and regional tsunami warning systems.
The Tsunami Warning System
The underlying principle is based on the difference between the speeds of seismic waves and tsunami waves. Seismic waves travel much faster and provide ample time for scientists to predict a tsunami, making it easy to ring the alarm long before a tsunami can take place.
An early alarm helps to save many lives. Many ships and ocean vessels are also saved from these killer waves.
In spite of all human efforts to fight against this catastrophe, the best that can be done is to provide an early warning to people in the coastal areas. At times, even that may not be possible, showing us that we are no match for mother nature's fury.