More than 23 lakh houses have been destroyed and lakhs of people have lost their lives. The possibility of an earthquake in Japan?

For the first time, geologists in Japan have predicted a 'great earthquake' after the recent 7.1 -magnitude earthquake on the coast of the Pacific Ocean. A massive earthquake in the geographical area known as Nankai Tro, or Nankai geological gap, is feared to cause massive loss of life and economic losses worth millions. What is a Minor Earthquake and What are the Risks?

What is the warning about?
A strong earthquake hit the southern coast of Japan four days ago. There were two earthquakes within a few minutes. The earthquake measured 7.1 on the Richter scale. After this earthquake, Japanese geologists have predicted an even bigger earthquake. This earthquake is known as the Nankai Trough Earthquake. However, Japan's Nankai Tro Earthquake Advisory Committee said that the possibility of a major earthquake after a 7 magnitude tremor is very low. This can happen only once in a hundred cases. Earthquakes with a magnitude of more than 8 are called megaquakes. Japan has predicted that the next Nankai-Tro earthquake could be as strong as 9.1 -magnitude. Naoshi Hirata, a professor at the University of Tokyo who chairs the advisory committee, said residents in areas hit by such disasters should be on alert for a week and then begin the evacuation process.
What exactly is Nankai Tro?
Nankai Tro is a geologic rift located in the south of the Nankai region of the island of Honshu, Japan. The rupture is the source of the devastating earthquake, which extends about 900 kilometers to the coast. In this area, the Philippine Sea Plate or the landmass is moving under the Eurasian Plate. Earthquakes can occur every 100 to 150 years. The Japanese government had previously predicted a 70 to 80 percent chance of an 8 to 9 magnitude earthquake in the next 30 years. According to the US Geological Survey, the intensity of an earthquake is related to the length of the fault on which it occurs. The largest earthquake ever recorded was a 9.5 -magnitude temblor on May 22, 1960, on a fault about a thousand miles long in Chile.

What damage can be caused by an earthquake?
Earthquakes occur once every 100 to 150 years. The earthquake is expected to be bigger than Japan's March 2011 earthquake. The quake could affect areas from central Shizuoka to southwestern Mizzaki, about 150 kilometers from Japan's capital, Tokyo. Tsunami waves of up to 30 metres (98 feet) can hit within minutes of an earthquake. The intensity of the tsunami depends on the intensity of the earthquake and the tidal conditions. Landslides and fires are feared in some areas. It is estimated that 23 lakh houses have been destroyed and lakhs of people have lost their lives. Geologists said many people would be forced to evacuate to avoid further damage. Economic losses from the earthquake could be as high as 220 trillion yen (about 1,25,926 billion rupees), or more than one-third of Japan's annual gross domestic product. It could also hit industries producing four-wheelers and other major Japanese products. Earthquakes can also have long-term effects on infrastructure and supply chains.

When was the last major earthquake?
According to Japanese historical records, the Nankai-Toro earthquake has occurred several times since 684. Due to this, tsunami waves often hit the coastal villages. The most recent Nankai Tro earthquake occurred in 1946. The quake measured 8.0 on the Richter scale. The 6.9 -metre tsunami killed 1,330 people. Two years ago, in 1944, there was an 8.1 -magnitude earthquake. The 10-meter tsunami killed 1,251 people. In the 19th century, two major earthquakes killed thousands of people. Japan has been hit by earthquakes at least once in a century.