What is an Earthquake?
Earthquakes are terrifying tremors that are caused by tectonic plates and can destroy entire towns. Everyday many earthquakes happen, but most of them aren’t strong enough to be felt. Earthquakes happen when two tectonic plates converge, diverge or transform. Creating violent seismic waves that shake whatever is above the epicentre in the earth. There are many large earthquakes in history which have taken many lives and destroyed entire cities, like the 2004 Indonesian earthquake. Some earthquakes have also triggered many other disasters like Tsunamis, Avalanches, Volcanic Eruptions and Landslides. Earthquakes are measured by the Richter scale. This scale ranges from 0.0 (micro) to 10.0 (extreme). This scale was developed by Charles Richter and is used worldwide to measure every felt earthquake. The scale can go higher but no earthquake higher than 9.5 has ever been recorded.
What type of earthquake was it?
The Japan earthquake was a Megathrust earthquake. A Megathrust earthquake happens when one tectonic plate is subducted by another one. Once the plate crashes back into place, it releases a huge lot of energy. Megathrust earthquakes are known for being the most powerful, according to Wikipedia, since 1900, there have been 6 earthquakes that exceeded 9.0 that were each megathrust earthquakes. No other earthquake type has been known to have as much power. In the case of the Japan one, it was the Pacific Plate subducting beneath the Okhotsk Plate.
The Japan earthquake was a Megathrust earthquake. A Megathrust earthquake happens when one tectonic plate is subducted by another one. Once the plate crashes back into place, it releases a huge lot of energy. Megathrust earthquakes are known for being the most powerful, according to Wikipedia, since 1900, there have been 6 earthquakes that exceeded 9.0 that were each megathrust earthquakes. No other earthquake type has been known to have as much power. In the case of the Japan one, it was the Pacific Plate subducting beneath the Okhotsk Plate.
What are the different types of earthquakes?
There are 7 different types of earthquakes – each producing that scary shake. The first of the 7 is the Blind Thrust earthquake. The Blind Thrust earthquake is an earthquake that happens on a never-before noticed fault line, this earthquake isn’t very strong but sometimes they are the most destructive. Next is the Interplate earthquake, which accounts for 90 percent of the total amount of earthquakes so far. These occur when two plates interact with each other and create a sort of ‘stress.’ They stay locked until the sufficient ‘stress’ is produced, once they slip, it results in seismic waves of which travel along the earth’s surface. Another is the Intraplate earthquake, which happens in the interior of any tectonic plate. Intraplate earthquakes are very rare and large versions of these can inflict huge damage. Next is the Slow Earthquake, which is an earthquake with long energy release over a period of hours to months, instead of a seconds to minutes like a typical earthquake. Also they are quiet compared to a normal earthquake, but are still capable of causing large tsunamis and damage. An underwater earthquake is an earthquake which occurs at the bottom of a body of water, mostly in/under an ocean and are the leading cause of Tsunamis. Last but not least is the Earthquake Swarm, where many earthquakes happen in a short period of time. These earthquakes are typically preceding volcanic eruptions.
Did anything happen after the earthquake?
After the earthquake, 2 main disasters happened. The first one was the Tsunami. The earthquake had caused a 6 to 8 metre push up on a 180km wide seabed, around 60km offshore of the east coast of Tokohu, a city in Japan. It resulted in a huge tsunami, which brought heaps of destruction along the Pacific coastline of Japan’s northern islands. More than thousands of lives were lost to this event, entire towns completely devastated. It reached the entire Pacific coast of many countries like North and South America – Alaska to Chile. There were lots of warnings issued and evacuations carried out in heaps of countries bordering the Pacific. The Tsunami hit a lot of the places but the destruction was minor. There were waves around 40.4 metres high affecting the eastern coast of Japan. Another event that was caused after the earthquake was the Fukashima Nuclear Plant Meltdown. This event was rated 7 on the INES or International Nuclear Event Scale, 1 is the lowest, 7 is the highest. The only disaster in close comparison was the Chernobyl Incident. Basically, the reactors overheated due to the failure of the cooling system, which was flooded because of the Tsunami. Traces of Radiation were found all around the areas of Fukashima and beyond. It has since increased the chances of anybody born in the area around Fukashima to have a more likely chance of contracting cancer. In August 2013, it was found that the plant was leaking radioactive material into the sea.
How many deaths/injuries/missing were found? Also what was the damage to infrastructure?
When it comes to natural disasters, Mother Nature shows no mercy. The earthquake and tsunami took 15,883 lives, caused 6,145 injuries in individuals and 2,656 people missing. As well as 129,225 buildings completely collapsed, 254,204 structures ‘half-collapsed’ and 691,766 buildings with partial damage.
Was Japan prepared for a disaster like this?
Japan was prepared for the earthquake with earthquake monitor and tsunami warning system. The
monitor is the most sophisticated and most expensive one in the world. It has been upgraded quite a
few times and have been there ever since the earthquake in 1952. Tsunami warning systems are
located in 180 seismic stations all over Japan. Japan also had a TV signal that immediately tells
you when the system senses a big wave approaching the shore, the system also has sirens if your
outside. Japan has countless concrete breakwaters and floodgates to protect the ports and coastal areas around Japan. All the protection costs about 20 million to build.
monitor is the most sophisticated and most expensive one in the world. It has been upgraded quite a
few times and have been there ever since the earthquake in 1952. Tsunami warning systems are
located in 180 seismic stations all over Japan. Japan also had a TV signal that immediately tells
you when the system senses a big wave approaching the shore, the system also has sirens if your
outside. Japan has countless concrete breakwaters and floodgates to protect the ports and coastal areas around Japan. All the protection costs about 20 million to build.
What lessons have been learnt from the earthquake and tsunami?
This earthquake was obviously unexpected in size and extreme power, it helped scientists learn more about the faults in Japan, and also the world. It proved to them that 400-500 years of data isn’t enough. When the first wave hit, a warning message was sent to 124 television centres and 52 million phones but only in some parts of Japan that were hit by the initial wave. Seismologists didn’t think that further warning was needed, but they were wrong. Residents on the coastal areas of Japan weren’t notified of the impending tsunami, because either they already evacuated after the earthquake or their televisions/radios were damaged from the earthquake. Even though the tsunami only hit 40-60 minutes after the earthquake, many people were unaware of it happening. Because of Japan’s preparations for disasters like earthquakes, the shaking wasn’t the cause for most of the deaths – it was the tsunamis. On the bright side, it gave scientists a well recorded large earthquake to study and help make better earthquake models, which in turn will help scientists forecast future disasters and understand our planet further.