Earthquake on December 26, 2004 in Southeast Asia, the largest in the last 40 years and the fifth largest since 1900, there were nine on the Richter scale. Earthquake and tsunami that followed caused the disaster that killed more than 220,000 people. Fault area of 1000 square kilometers which arise due to the movement of plates beneath the earth's surface and a giant energy generated by the huge chunks of land changing places, combined with the energy giant that occurred in the ocean to form a tsunami. The tsunami waves that hit Southeast Asian countries like Indonesia, Sri Lanka, India, Malaysia, Thailand, Bangladesh, Myanmar, Maldives and Seychelles, and even the coast of Africa like Somalia, which lies approximately 5000 kilometers so far.
The term "tsunami," which in Japanese means harbor wave, becoming part of the giant post-tsunami world language Meiji on June 15, 1896 that hit Japan and caused 21,000 people lost their lives.
To understand the tsunami, it is important to be able to distinguish it from the tidal movements and ordinary waves caused by wind. The wind that blew over the ocean surface currents that cause limited to the upper ocean layer by generating waves is relatively small. For example, the divers with air tubes can easily dive down and reach the layer of still water. Ocean waves may reach as high as 30 meters or more during the storm, but this does not cause water movement at depth. In addition, the speed of regular sea waves caused by wind is not more than 20 km / hr. In contrast, the tsunami waves can travel at speeds 750-800 km / hr. Tidal wave moving in the earth's surface twice in the span of a day and, like the tsunami, can cause currents to reach the bottom of the ocean depths. However, unlike the tidal wave, tsunami waves are not the cause of gravity and the moon.
Tsunamis are sea waves formed long berperiode due to energy propagating into the ocean due to earthquakes, volcanic eruptions and the collapse of the layers of the earth's crust caused by the natural disasters in the ocean or in the seabed, an event that involves the movement of the earth's crust as the plates shift on the seabed, or the impact of a meteor collision. When the bottom of the ocean floor moved at high speed, the entire burden on top of sea water affected. What happens at the bottom of the ocean floor can be seen the effect on sea levels, and overall burden of sea water, to depths of 5000-6000 meters, move together in waves. One series of hills and valleys of the wave until it can cover an area measuring 10,000 square kilometers.
No impact TSUNAMI IN SEA OFF
On the high seas in the form of tsunami is not a wall of water as most people imagined, but generally represents less than one berketinggian wave meter with a wavelength of about 1000 kilometers. Here can be understood that the sloped surface wave is very small (1 cm in height that stretched as far as 1 km). In ocean areas inside and out, a wave like this can happen without a perceived, though moving at a speed of 500 to 800 km / hr. This is because the effects disguised by unusual sea surface waves. To better understand how high the speed of tsunami waves, we can say that the waves are capable of matching the speed of the Boeing 747 jet aircraft. The tsunami that occurred on the high seas will not be felt even by ships.
TSUNAMI 100 000 TON AIR move to the mainland
Research shows that the tsunami was not comprised of a single wave, but rather consists of a series of waves with a single center in the middle, like a stone thrown into a swimming pool. The distance between two successive waves can reach 500-650 miles. This means that tsunamis can cross oceans in a matter of hours. Tsunami only release the energy when approaching the coast. The energy is divided evenly on the roll of a giant water becomes more dense along with the mengerutnya coil spring, the high and rising fast surface waves can be observed. Berketinggian waves less than 60 cm on the high seas to lose speed when approaching shallow waters, and the distance was reduced antargelombangnya. However, the wave of the tsunami led to overlap each other by forming a wall of water. These giant waves, which normally reaches a height of 15 meters but rarely exceed 30 meters, off the coast of great power when hit at high speed, causing severe damage and claimed many casualties.
Tsunamis move more than 100,000 tons of sea water to the mainland for every meter of the coastline, with a destructive force that is difficult to imagine. (The largest tsunami wave ever known, which hit Japan in July 1993, an increase of up to 30 meters above sea level.) Early warning sign is usually not a wall of water, but an abrupt rise and fall of sea water.
TSUNAMI-LARGE TSUNAMI IN HISTORY
Giant sea waves caused by the largest earthquake recorded in history are as follows
The oldest giant waves never be known due to earthquake in the sea, which was named "tsunami" by the Japanese and "hungtao" by the Chinese people, is occurring in the eastern Mediterranean on 21 July 365 AD and killed thousands of people in the town of Iskandariyah , Egypt.
Portugal's capital Lisbon, destroyed by a devastating earthquake on November 1, 1775. Atlantic ocean waves that reached an altitude 6 meters devastated beaches in Portugal, Spain and Morocco.
August 27, 1883: Indonesia's Krakatoa volcano eruption and tsunami waves that swept the coasts of Java and Sumatra, killing 36,000 people. The volcanic eruption was so powerful during the nights sky glowing red lava due to dust.
June 15, 1896: "Sanriku Tsunami" struck Japan. Berketinggian giant tsunami that swept the 23 meters of the crowd that gathered in the celebration of religion and swallowing 26 000 casualties.
December 17, 1896: Tsunami damage to the embankment of Santa Barbara in California, United States, and caused flooding on major roads.
January 31, 1906: Earthquake in the Pacific ocean to destroy some of the city of Tumaco in Colombia, including the entire house on the beach that lies between Micay Rioverde in Ecuador and Colombia; 1500 people died.
1 April 1946: The tsunami that destroyed the Scotch Cap lighthouse on the Aleutian Islands along with five guards, moving toward Hilo in Hawaii, killing 159 people.
May 22, 1960: berketinggian 11 meters Tsunami kills 1,000 in Chile and 61 in Hawaii. Giant waves across the Pacific ocean to the shore and shook the Philippines and the island of Okinawa in Japan.
March 28, 1964: Tsunami "Good Friday" in Alaska eliminate the three villages from the map with 107 residents were killed, and 15 people died in Oregon and California.
August 16, 1976: Tsunamis in the Pacific killed 5,000 people in the Moro Gulf, Philippines.
July 17, 1998: Sea waves caused by earthquakes which occurred in the northern part of Papua New Guinea, killing 2313 people, destroyed seven villages and caused thousands of people homeless.
December 26, 2004: An earthquake measuring 8.9 on the Richter scale and giant sea waves that struck six countries in Southeast Asia killed more than 156 000 people.
TSUNAMI DAMAGE CAUSES POWER HIGH
According to information provided by Dr. Walter C. Dudley, a professor of oceanography and co-founder of the Pacific Tsunami Museum, no matter how big the earthquake strength, the movement of ocean floor is a requirement of the tsunami. In other words, the greater the displacement of the earth crust in the bottom of the ocean floor, the greater the amount of water She moved, and this will increase the magnitude of the tsunami. Another thing that increases the power of tsunami damaged coastal structures is diterjangnya: In addition to factors such as the shape of the bay beach or peninsula, flat or steep, part of the beach which is always in the water may have a structure that can increase the magnitude of the killer waves.
In another statement, which clarifies that preventive measures taken can not be regarded as a perfect solution, Dudley said that the United States and Japan have established the most sophisticated monitoring devices in the Pacific Ocean, but all this device has an error rate of fifty percent!
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