By: Jessica Lerner
On March 11, 2011, an 8.9 earthquake caused a 10-meter tsunami along the northeastern coast if Japan. More than 10,000 people are dead, and it generated a hydrogen explosion and a nuclear meltdown. However, how many of us actually know what a tsunami is?
According to the National Oceanic and Atmospheric Administration (NOAA), a tsunami is a “set of ocean waves [or a wave train] caused by any large, abrupt disturbance of the sea-surface.” The severity of the disturbance and the proximity of the tsunami to the coastline affects the destruction done to local communities.
Tsunamis can be caused by sudden displacements in the sea floor, volcanic activity, landslides, and most commonly earthquakes. Major tsunamis can be generated from earthquakes with a magnitude over 7.0.
Tsunamis more frequently take place in the Pacific Ocean, due to the denser oceanic plates sliding under the lighter continental plates. The fracturing of these plates allows for an upward movement, where the energy is transferred from the earth to the sea floor.
An earthquake is a sure-fire sign that a tsunami may be approaching. Also, a tsunami may be preceded by a change in the water level. In fact, some experts believe that a receding ocean may allow for five minutes heads notice. It is always a good idea to get to higher ground if a tsunami may be on its way.
The first wave of a tsunami is not always the most dangerous. Tsunami danger can last up to hours. It is advised to stay out of harm’s way until it is clear to return.
In 2004, an earthquake with a magnitude from 9.1 to 9.3 hit the Indian Ocean. This earthquake trigged a series of disastrous tsunamis, making it one of the top ten deadliest disasters recorded in world history. The first wave was 33-meters, which became the largest earthquake-generated tsunami. 230,210 people from Indonesia, Thailand, India, Malaysia, Sri Lanka, and the Maldives died. The tsunami even hit in eastern Africa.
What is unusual about this tsunami is there were scuba divers diving in Thailand whom were oblivious to the disaster happening. Faith Wachs was diving with her husband when they noticed a worsening in water visibility, and they felt as though they were being pulled down.
Upon surfacing, they were surprised to see trash and rubble in the ocean; they thought a boat had crashed. Only once the dive master’s wife texted him about the disaster did they understand what had happened.
In 2007, an earthquake with a magnitude of 8.1 caused a 5-meter tall tsunami. In the Solomon Islands, it traveled from 300 to 400-meters inland. The death toll was only fifty-two, but the damage done was severe. A few months later in Japan, a 6.8 earthquake caused a tsunami that was 20-centimeters in height.
In 2010, after an 8.8 earthquake in Chile, tsunami warnings were issued in fifty-three countries. The earthquake undoubtedly caused the tsunami, which caused damage in the south-central towns of Chile. San Diego, California and Japan managed to experience only slight damage.
Less than a month ago in New Zealand, a 6.3 earthquake hit. The earthquake caused about 30 million tones of ice to tumble off the Tasman Glacier into the Tasman Lake. This, in turn, caused a tsunami of 3.5-meters in heights.
Even though, tsunamis seem to plague the other side of the world, it is important to know the warning signs and be prepared if one is ever in this situation.
