 Including the new extension out into the Genkai Sea, the Kego fault is now thought to be long.Following reports that the city has only prepared for earthquakes up to a magnitude of 6.5, several strong aftershocks renewed fears that the quakes might cause the portion of the Kego fault that lies under the city to become active again, leading to an earthquake as big as, or bigger than, the March 20 quake.Fukuoka has 7 wards ("ku").