Background on Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. Japan is an archipelago of 6,852 islands, the four largest being Honshu, Hokkaido, Kyushu and Shikoku. Together, these four islands hold about 97 percent of the country's land area. Japan has the world's tenth-largest population, with more than 126 million people. As of 2012, Japan is the third largest national economy in the world, in terms of nominal GDP, and the fourth largest national economy in the world, in terms of purchasing power parity. Japan is very well industrially developed, and is home to some of the largest and most technologically advanced producers of motor vehicles, electronics, machine tools, ships, chemical substances, textiles, and others. Japan is a multiple hazard location. They deal a lot with earthquakes, tsunamis and volcanic eruptions for a long time now due to their geographical location.
http://en.wikipedia.org/wiki/Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. Japan is an archipelago of 6,852 islands, the four largest being Honshu, Hokkaido, Kyushu and Shikoku. Together, these four islands hold about 97 percent of the country's land area. Japan has the world's tenth-largest population, with more than 126 million people. As of 2012, Japan is the third largest national economy in the world, in terms of nominal GDP, and the fourth largest national economy in the world, in terms of purchasing power parity. Japan is very well industrially developed, and is home to some of the largest and most technologically advanced producers of motor vehicles, electronics, machine tools, ships, chemical substances, textiles, and others. Japan is a multiple hazard location. They deal a lot with earthquakes, tsunamis and volcanic eruptions for a long time now due to their geographical location.
http://en.wikipedia.org/wiki/Japan
Cause of the earthquake
The Tohoku earthquake was caused by by movement of two of the Earth's tectonic plates against each other.The Pacific plate (underlying the Pacific Ocean) is colliding with the Okhotsk plate (under Japan) at around 9 cm every year. Because the Pacific plate is denser than the Okhotsk plate, it dives down into the Earth along what is called a "subduction zone". As the Pacific plate subducts beneath the Okhotsk Plate, friction between the two causes them to lock against each other. Eventually, enough stress builds up to overcome the friction, and the Pacific plate slides toward and beneath Japan, causing an earthquake. The break caused the sea floor to rise by several meters. When the pressure caused by subduction and built up for centuries is suddenly released an earthquake occurs.
http://www.livescience.com/27773-how-japan-s-2011-earthquake-happened-infographic.html
The Tohoku earthquake was caused by by movement of two of the Earth's tectonic plates against each other.The Pacific plate (underlying the Pacific Ocean) is colliding with the Okhotsk plate (under Japan) at around 9 cm every year. Because the Pacific plate is denser than the Okhotsk plate, it dives down into the Earth along what is called a "subduction zone". As the Pacific plate subducts beneath the Okhotsk Plate, friction between the two causes them to lock against each other. Eventually, enough stress builds up to overcome the friction, and the Pacific plate slides toward and beneath Japan, causing an earthquake. The break caused the sea floor to rise by several meters. When the pressure caused by subduction and built up for centuries is suddenly released an earthquake occurs.
http://www.livescience.com/27773-how-japan-s-2011-earthquake-happened-infographic.html