 It was also called , (Shimabara means the central mountain of the Shimabara Peninsula) since many people were killed by this tsunami in Higo (Kumamoto Prefecture, situated away across the Ariake Sea).Towards the end of 1791, a series of earthquakes occurred on the western flank of Mount Unzen which gradually moved towards Fugen-dake (one of Mount Unzen's peaks).In February 1792, Fugen-dake started to erupt, triggering a lava flow which continued for two months.