Survivor Family – Tsunami

By Coyalita Linville

Survivor Family – Tsunami – What Is a Tsunami? A tsunami is a massive wave or series of waves that can be anywhere from ten to a thousand feet high.

Tsunamis hit the coastline with deadly force, causing damage to property, the natural environment, and great loss of life.

Tsunamis don’t occur spontaneously. They’re triggered by earthquakes, landslides, underwater volcanic activities, meteor impacts and other causes.

Most tsunamis are caused by earthquakes and most large-scale earthquakes are followed by dangerous tsunamis, especially if they occur underwater.

Another word for tsunami is tidal wave, which is a misnomer because tsunamis are not related to the moon or its tides. They are also called seismic sea waves, another misnomer because non-seismic activity such as a landslide can also trigger a tsunami.

How Tsunamis Occur

A tsunami is caused by a massive displacement of water. If you fill a bowl with water and drop a rock into the bowl, you’ll get a simple demonstration of how a tsunami works. The water is displaced and flows over the edges of the bowl.

The same thing happens when there is an earthquake or other disturbance in the ocean, but instead of the water flowing over the edge of the bowl, it comes crashing to the shore.

Tsunamis are most commonly caused by earthquakes. During an underwater earthquake, a tectonic plate slides under an adjacent plate.

The ensuing earthquake causes an uplift of sea water, and the result is a tsunami. The displaced water moves toward the coast, getting bigger as it flows along.

In this scenario, tsunamis can go multiple directions at once. Usually, the largest wave or series of waves hits the nearest shore, while its other half reaches other shores hours later.

This is what happened in the massive Chilean tsunami of 1960. The main wave crashed on the shores of Chile and hours later, smaller but still dangerous waves crashed on the shores of Japan, New Zealand and elsewhere.

A tsunami travels at amazing speed. As it moves across the ocean, its speed and size build up energy which makes it more powerful when it hits the shore.

It’s not uncommon for a tsunami to be over 30 feet tall. Waves can be higher than tall buildings and they can smash entire coastal towns.

The World’s Deadliest Tsunamis

From the earliest times of recorded history, there have been large-scale tsunamis that wiped out entire cities and left hundreds of thousands of dead.

The earliest reported tsunami was a series of deadly waves that left an estimated 100,000 dead on the Greek islands of Crete and Santorini. In 1755, tsunamis swept across coastal Europe and killed around 100,000 people in as far away countries as Morocco, Portugal, Ireland, and the United Kingdom.

The biggest tsunami ever recorded was at Lituya Bay on the coast of Alaska in 1958. Now referred to as a ‘Mega tsunami,’ it was 1,740 feet at its crest. Only around 30 people died.

In 1960, the 9.5-magnitude Valdivia earthquake sent massive waves to the coasts of Chile, Hawaii, Japan, the Philippines, New Zealand and the Aleutian Islands of Alaska. The death count is unknown, but estimates go as high as 6,000 people.

The deadliest tsunami in recorded history was from an earthquake in the Indian Ocean in 2004 that left 350,000 dead or missing in Sumatra, India, Sri Lanka and Thailand.

In 2011, a 9.0 magnitude earthquake off the coast of Tohoku in Northern Japan sent a deadly wave to the mainland. In addition to sweeping away whole towns and killing an estimated 19,000 people, it also set off the second-biggest nuclear meltdown in history.

Japanese Prime Minister Naoto Kan called the triple disaster of the earthquake, tsunami and meltdown ‘the toughest and most difficult crisis for Japan since World War II.’