Japanese authorities are urging people in a wide section of the country to take precautions against a possible mega-earthquake.
They have issued a special advisory for the first time. This comes after a powerful quake rocked Kyushu on Thursday.
The advisory is part of a precautionary measure being taken against a possible mega earthquake. The measure is known as the Nankai Trough Earthquake Extra Information protocol.
The Japan Meteorological Agency says there is a relatively high possibility that a giant earthquake will strike the area where the Nankai Trough is located. If a large-scale earthquake occurs in the future, strong tremors and large tsunami are expected. While the possibility is now higher than usual, the agency notes this does not mean that something will definitely occur during a certain period of time.
A magnitude 7.1 quake struck southwestern Japan on Thursday, and more tremors hit the area through Friday. Experts note that seismic activity remains high.
The Meteorological Agency is urging municipalities in the region that extends from the areas around Tokyo to those in southern Okinawa Prefecture to check their earthquake preparedness.
Officials are advising people to secure pieces of furniture, so that they will not fall. The authorities are also advising people to make note of evacuate sites and ways to confirm that family members are safe. They say households with infants, seniors or people with disabilities should consider evacuating voluntarily.
Experts believe that the Nankai Trough quake could occur along the plate boundary between Suruga Bay in Shizuoka Prefecture and the Hyuganada Sea off Kyushu. They believe there is a 70 to 80 percent chance that it will strike within the next three decades and have a magnitude in the range of 8 to 9.
According to a recent government estimate, in the worst-case scenario, it could claim more than 230,000 lives and destroy about 2 million buildings.