FUKUOKA - The Kego Fault Zone running through central Fukuoka could produce an earthquake with a maximum seismic intensity of 7, leaving 1,800 people dead, 800 disaster-related deaths and 319,000 evacuees, according to prefectural damage estimates, as experts warn that an unruptured section may remain under stress.
The magnitude 7-level earthquake that struck Kumamoto on July 28 and registered a maximum intensity of 7 may have been influenced by a section of the fault that did not rupture during the 2016 Kumamoto earthquakes. Specialists say a similar type of earthquake could occur in Fukuoka.
Mitsuteru Asai, a professor specializing in disaster prevention engineering at Kyushu University's Faculty of Engineering, said the latest earthquake was linked to an unruptured section of the Hinagu Fault, which was involved in the earthquakes 10 years ago.
"The Hinagu Fault was deeply involved in this Kumamoto earthquake," Asai said. "During the first Kumamoto earthquake 10 years ago, the foreshock occurred at the northern end of the Hinagu Fault. The fault has remained under stress since then, and the central and southern sections that had not yet ruptured continued to be in a state where they could break more easily. One of those sections ruptured this time."
The Kego Fault Zone, which runs through the center of Fukuoka, is believed to face a similar risk from an unruptured section.
The 2005 Fukuoka Prefecture Western Offshore Earthquake occurred in the northwestern part of the Kego Fault Zone, but the southeastern section did not move and remains unruptured.
The government's Headquarters for Earthquake Research Promotion classifies both the southeastern section of the Kego Fault Zone and the Hinagu Fault Zone as S-rank, its highest danger category.
"The Fukuoka Prefecture Western Offshore Earthquake can be considered an event involving part of the Kego Fault, and the fault lies along its extension," Asai said. "People should understand that the Kego Fault is now in a state where it has been subjected to stress. In terms of seismic intensity, upper 6 and, depending on the location, 7 are entirely possible. I hope people learn from this Kumamoto earthquake that they need to prepare in their daily lives."
Fukuoka Prefecture has estimated the damage that could occur if an earthquake originates in the southeastern section of the Kego Fault Zone.
The scenario assumes a magnitude 7.7 earthquake with a maximum seismic intensity of 7.
The prefecture estimates that 1,800 people would be killed, with a further 800 disaster-related deaths. About 12,000 people would be injured, 319,000 would be forced to evacuate, and 36,000 buildings would be completely destroyed or burned down.
The projections underscore the need for residents to recognize that a major earthquake could strike at any time and to treat the danger as a direct threat rather than a distant possibility.
Source: FBS
