The Break Guide To Tsunamis

blawsome by blawsome on Feb. 26, 2014

tsunami wreckasge

The subject of disaster films, tsunamis were not a reality in the public consciousness until this past decade when the world witnessed two of the most devastating tsunamis in recent history.  First in 2004, the Indian Ocean tsunami killed more than 250,000 people in 15 countries and is considered to be the most destructive tsunami in modern times.  Then in 2011, off the coast of Tohoku, Japan, another gigantic tsunami killed close to 16,000 people.  Both tsunamis were caused by 9.0 earthquakes that happened under the nearby surrounding ocean.

See in this video footage from Thailand how the ocean is first calm until suddenly a gigantic wave sweeps on shore:

From the perspective of a small boat as a tsunami approaches:

WHAT CAUSES A TSUNAMI?

In Japanese, tsunami means "harbor wave" because sometimes Japanese fisherman would sail out to sea to go fishing and experience nothing unusual only to come home and find their village destroyed by a huge wave.  Tsunamis are possible wherever there are large bodies of water however, tsunamis are not tidal waves since they have nothing to do with the tides.  A tsunami is a series of huge waves that are generated as a result of some kind of violent underwater disturbance such as an earthquake, a volcano eruption, glacier breaks, landslides, underwater detonations or in rare instances, meteorite impacts.  Underwater earthquakes are the most frequent causes of tsunamis. 

Earthquakes happen when the tectonic plates underneath the earth's surface move and one plate slips under another.  When the jagged edges of the plates get caught and then subsequently release, these “megathrust,” earthquakes send out a huge jolt of energy that displaces ocean water, causing it to rise above sea level. Gravity forms the water into waves that travel in all directions from the epicenter of the disturbance.  The waves can travel in the open sea with incredible power and speeds up to 450 miles per hour, traveling faster than a commercial jet.  However, the waves are not particularly big and that is why it is difficult to detect an oncoming tsunami.  The waves slow down as it enters shallow water and gets close to shore but it also grows in height and gets bigger. Waves can grow as high as 100 feet and a large tsunami can have many waves that reach shore over a period of hours with subsequent waves growing larger than the last.  Once a wave crashes onto shore, it keeps traveling inland destroying whatever is in its path.

WHAT IS THE HISTORY OF TSUNAMIS?

Geologists say tsunamis have occurred from as far back as almost 4,000 years in China and others hypothesize that tsunamis are the source of ancient legends, such as the parting of the Red Sea during the exodus of the Israelites from Egypt.  Here is a chart illustrating the deadliest tsunamis in history.

Location

Date

Fatalities

1. Indian Ocean

2004

225,000

2. Crete-Santorini, Ancient Greece

1410 B.C.

100,000

3. Portugal-Morocco

1755

60,000

4. South Sea China

1782

40,000

5. Krakatau, Indonesia

1883

36,500

6. Tokaido-Nankaido, Japan

1707

30,000

7. Sanriku, Japan

1896

26,360

8. Northern Chile

1868

25,674

 

 

 

 

WHERE DO TSUNAMIS HAPPEN?

Tsunamis have been historically recorded in every ocean on earth but 80% of all tsunamis occur in the “Ring of Fire,” a 25,000-mile horseshoe-shaped string of volcanoes and sites of earthquake activity located around the edges of the Pacific Ocean.  There have only been two large tsunamis in Europe.  In 1530 B.C., a tsunami hit Crete and the surrounding Mediterranean coasts and in 1755, another one struck Lisbon, Portugal.

WHAT CAUSED THE 2004 INDIAN OCEAN QUAKE AND TSUNAMI?

On Sunday, December 26, 2004, a 9.0 megathrust undersea earthquake happened at 7:58AM local time lasting between 8.3 and 10 minutes.  The epicenter was off the west coast of Sumatra, Indonesia where the Indian Plate slipped under the Burma Plate, triggering a series of tsunamis along the coasts of most landmasses bordering the Indian Ocean with waves that traveled 375 miles in 75 minutes which is 300 miles per hour, devastating 15 countries.  Some waves reached a height as high as 100 feet. 

The earthquake caused a part of the seafloor as large as the size of California to move upwards by more than 30 feet which displaced a huge amount of water.  The hardest-hit country was Indonesia followed by Sri Lanka, India then Thailand.   Many who were killed were women and children since the women were reportedly waiting on the beaches for their husbands to return from fishing and the children were not strong enough to fight the overwhelming currents. It’s estimated one third of the dead were children and in some countries, four times as many women as men were killed. Additional victims included about 9,000 tourists from the U.S., Sweden, the United Kingdom and Australia who were vacationing at Southeast Asia beach resorts.

An showing the full strenght of the 2004 Indian Ocean tsunami:

One of the most famous survival stories that came out of the disaster is the story of Czech model Petra Nemcová who was vacationing at a resort in Thailand with her fiancé and photographer, Simon Atlee.  During the tsunami, Atlee drowned but Petra was able to hold onto the top of a palm tree for hours and survive despite a broken pelvis and serious internal injuries.  She was eventually rescued by Thai civilians and airlifted to a hospital.  Nemcová wrote about this experience in her book, “Love Always, Petra” and donates all the proceeds from the sales of the book to charity.  Nemcova also started The Happy Hearts Fund in 2005, a non-profit that advocates and provides for disadvantaged youth who were victims of the tsunami.

Petra in the hospital after being rescued:

petra nemcova in hospital

If there is anything positive to note about this horrific disaster is that the plight of the tsunami devastated countries and people prompted a worldwide humanitarian response of $14 billion dollars in aid.  The tsunami also uncovered the lost city Mahabalipuram in India which historically was the capital of a powerful kingdom that got “swelled by the sea” at the height of its glory.  The city is now a tourist destination.

HOW DID THE 2011 TSUNAMI IN JAPAN HAPPEN?

On March 11, 2011, a 9.0 undersea megathrust earthquake happened in the northwestern Pacific Ocean 81 miles off the coast of the Japanese city of Sendai.  The quake occurred at 2:46pm local time when The Pacific Plate slipped beneath a northern Honshu plate.  The quake lasted about six minutes with the epicenter at approximately 45 miles east of the Tohoku peninsula. The quake triggered a deadly 23 foot tsunami about 230 miles northeast of Tokyo in the Tohoku region causing massive devastation in the port cities of Iwate, Miyako and their surrounding towns.  The earthquake was the largest in Japan's history and left 15,839 people dead, 5,950 injured, and 3,642 missing.  However, Japan’s Earthquake Early Warning system sent out a warning to the general public 31 seconds after the earthquake occurred which is believed to have helped save many lives.  

Video footage shows giant waves deluging cities and rural areas, sweeping away everything in its path leaving behind death and destruction.  The quake also caused the cooling system in one of the reactors at the Fukushima Daiichi Nuclear Power Station in the nearby Fukushima prefecture to fail causing a nuclear crisis.  An explosion followed the first reactor failure and then partial meltdowns occurred in two other reactors.  A fire in another reactor caused radioactivity to be released into the air. Three other nuclear facilities also reported failure issues and more than 200,000 people had to be evacuated.  

Prime Minister Naoto Ka, named this disaster the "Great East Japan Earthquake," and at a March 13 news conference said, "I think that the earthquake, tsunami, and the situation at our nuclear reactors makes up the worst crisis in the 65 years since the war.” Estimated to be the world’s most expensive disaster in history, The World Bank calculated that costs of rebuilding the tsunami affected areas are at least $232 billion.  As with the 2004 Indian Ocean tsunami, worldwide relief efforts poured in even from some unexpected places.

CAN A TSUNAMI HIT THE U.S.?

Yes, and the states most at risk for tsunamis are the coastal ones that line the Pacific Ocean such as Alaska, Washington, Oregon, California and Hawaii with Hawaii being at the greatest risk due to its location.  The state averages about one tsunami a year and experiences a damaging one every seven year while the rest of the at-risk states experience a destructive tsunami about once every 18 years.  The most devastation by a tsunami to hit the western United States was on March 28, 1964 when an 8.4 earthquake hit Alaska.  Waves escalated as high as 21 feet, killing more than 120 people incurring damages costing $106 million.  Some experts say the US Pacific Northwest is long overdue for an earthquake with a magnitude of 8.0. or higher which can result in a tsunami.

 

The east coast can’t completely breathe a sigh of relief.  On Thursday June 13, 2013 around 3:30pm, there were reports of a 6 foot tsunami wave in the Barnegat Inlet in New Jersey.  Scientists think this tsunami was generated by an atmospheric disturbance like a rapid pressure change and call this type of tsunami a “meteotsunami.”  A tsunami caused by a landslide with extremely high waves is called a “mega-tsunami” and scientists are theorizing that the next mega-tsunami may occur in the Canary Islands in Spain. Due to the sheer force of this tsunami, there is a possibility of it crossing the Atlantic Ocean and hitting U.S. eastern coastal cities like New York, Boston, and Miami with 100 feet waves.  

WHAT ARE THE EFFECTS OF A TSUNAMI?

Besides the volume of lost human and animal lives, tsunamis can poison fresh water and groundwater systems as well as the soil by leaving large amounts of salt behind. Consequently, thousands of people can die of starvation and disease due to lack of clean water and food.  The devastation on buildings, roads, ships and infrastructure can cost billions of dollars in addition to years of rebuilding.  Nuclear reactors in the 2011 Japan tsunami melted down and sent radioactivity into the atmosphere.  These after effects are still unknown.

During the 2011 Japan Tsunami, a meltdown in one of the reactors at the Fukushima Daiichi Nuclear Power Station and resulting fire caused radioactivity to be released.

Cargo containers were strewn like matchsticks after the 2011 Japan Tsunami:

CAN TSUNAMIS BE PREDICTED?

Only the Pacific Ocean has an integrated multinational tsunami warning system and before the 2011 tsunami, Japan had the most advanced tsunami warning system in the world because of its long history with tsunamis. Their warning system consisted of more than 1,500 seismometers and more than 500 water-level gauges costing $20 million a year to run.

Although experts had recommended a tsunami warning system be installed, there wasn’t one for the Indian Ocean.  Because some animals may be able to sense impending natural disasters, hours before the 2004 Indian Ocean tsunami, people said they saw elephants and flamingos heading for higher ground while dogs and zoo animals refused to leave their shelters. After the tsunami there were very few dead animals.

Tsunami warning siren and sign:

HOW TO SURVIVE A TSUNAMI

One of the best ways to survive a tsunami is to be prepared for one.  During a tsunami, it’s best to escape on foot by climbing to a higher elevation, preferably at least 50 feet above sea level.  Using a car is not recommended since you can get stuck in traffic or run into other obstacles which will increase your chances of getting swept away.  After the first wave, do not return to your home unless authorized by government officials.  People often die going back home or to the beach to help the stranded because they think all is calm.  But since waves sometimes come in between long intervals, people wind up getting engulfed by another tsunami wave.  If you are caught in a tsunami, grab a floating object and let the current to carry you.  It’s better to not swim and fight the current which will either tire you out or engulf you.

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