Japan issues a megaquake alert due to increased risk.
When an earthquake strikes southern Japan, rocks fall and cameras tremble.
For the first time, Japan has warned of an increased likelihood of a "major earthquake" occurring soon. On Thursday evening local time, an advice was released cautioning residents to remain vigilant but not to flee.
It also emphasized that although there was a higher chance than usual, the warning did not indicate that a significant earthquake was about to occur.
It happened just hours after an earthquake of magnitude 7.1 struck off the southern island of Kyushu; no significant damage was reported.
However, because of the epicentre's location at the border of the Nankai Trough, a region of seismic activity that spans down Japan's Pacific coast, scientists were placed on high alert.
The Hyuganada Sea in Kyushu to the south and Suruga Bay in central Japan form the plate border. Thousands of people have died in past earthquakes around the Nankai Trough. The latest of these megaquakes was documented in 1946.
They have been observed happening once every 90 to 200 years. The Kyodo News agency reports that experts estimate there is a 70% to 80% likelihood that a magnitude 8 or 9 earthquake will occur anywhere in the trough within the next 30 years.
The worst-case scenarios indicate that the earthquake and possible wave might kill over 200,000 people.
Shinya Tsukada, a representative from the Japanese Meteorological Agency, stressed during a news conference on Thursday that although "there is a slightly greater chance of an additional significant earthquake compared to normal times," they were not guaranteeing it will occur "in a certain period of time."
The lower of two alert categories available to officials, this present advise, will remain in effect for one week. According to Japan's NHK broadcaster, it advises locals to be on increased alert in the upcoming days and for those who are unable to evacuate right away to think about doing so voluntarily.
Additionally, officials have advised people to continue living their normal lives while exercising caution and making sure that their homes are adequately stocked with supplies in case an evacuation is necessary.
