Tsunami is a Japanese word... Some facts in wake of the earthquake

 

Edited from National Geographic and the Huffington Post: A tsunami is a series of great sea waves caused by an underwater earthquake, landslide, or volcanic eruption. Tsunami (pronounced soo-NAH-mee) is a Japanese word, and in fact tsunamis are fairly common in Japan. Many thousands of Japanese have been killed by them in recent centuries.

 

Losses to property and casualty due to the horrible recent devastation will likely be higher than to people as entire homes and buildings were washed by the tsunami and many business locations were flooded. A Credit Suisse report says the initial reports estimate a range from $10 billion to $50 billion.

 

A tsunami is not a single wave but a series of waves, also known as a wave train. The first wave in a tsunami is not necessarily the most destructive. Tsunamis are not tidal waves. Tsunami waves can be as long as 60 miles (100 kilometers) and as far as one hour apart. They are able to cross entire oceans without great loss of energy.

 

Tsunamis As Fast as Commercial Jets

Where the ocean is deep, tsunamis can travel unnoticed on the surface at speeds up to 500 miles an hour (800 kilometers an hour), crossing an ocean in a day or less. Scientists are able to calculate arrival time of a tsunami in different parts of the world based on knowledge of water depths, distances, and when the event that generated the tsunami occurred. 

A tsunami may be less than a foot (30 centimeters) tall on the surface of the open ocean, which is why they are not noticed by sailors. But the powerful shock wave of energy travels rapidly through the ocean, sometimes as fast as a commercial jet. Once a tsunami reaches shallow water near the coast, it is slowed down. The top of the wave moves faster than the bottom, causing the sea to rise dramatically.

Geological features such as reefs, bays, river entrances, and undersea formations may dissipate the energy of a tsunami. In some places a tsunami may cause the sea to rise vertically only a few inches or feet. In other places tsunamis have been known to surge vertically as high as 100 feet (30 meters). Most tsunamis cause the sea to rise no more than 10 feet (3 meters).

Flooding can extend inland by a thousand feet (300 meters) or more. The enormous energy of a tsunami can lift giant boulders, flip vehicles, and demolish houses.The most damaging tsunami on record before 2004 was the one that killed an estimated 40,000 people in 1782 following an earthquake in the South China Sea.

 

The Pacific is by far the most active tsunami zone, according to the U.S. National Oceanic and Atmospheric Administration (NOAA). But tsunamis have been generated in other bodies of water, including the Caribbean and Mediterranean Seas, and the Indian and Atlantic Oceans.

North Atlantic tsunamis include the tsunami associated with the 1775 Lisbon earthquake, which killed as many as 60,000 people in Portugal, Spain, and North Africa. This quake caused a tsunami as high as 23 feet (7 meters) in the Caribbean.

The Caribbean has been hit by 37 verified tsunamis since 1498. Some were generated locally and others were the result of events far away, such as the 1775 earthquake near Portugal. The combined death toll from these Caribbean tsunamis is about 9,500.

 

Warning Signs

An earthquake is a natural tsunami warning. If you feel a strong quake do not stay close to shore. If you hear of an earthquake be aware of the possibility of a tsunami and listen to the radio or television for additional information. Remember that an earthquake can trigger killer waves thousands of miles across the ocean many hours after the event generated a tsunami.

 

Witnesses have reported that an approaching tsunami is sometimes preceded by a noticeable fall or rise in the water level. If you see the ocean receding unusually rapidly, that's a good sign that a tsunami may be on its way. Go to high ground immediately.

 

Many people were killed by the Indian Ocean tsunami because they went down to the beach to view the retreating ocean exposing the seafloor. Experts believe that a receding ocean may give people as much as five minutes' warning to evacuate the area.

You could also see National Geographic fans' pictures of earthquake effects and predicting the next giant earthquake and how nations rally to aid others after earthquakes, tsunamis, and ot.... Let us know if you'd like to help or if you have ideas how CREOpoint could help.