(4)The Tensho Earthquake (January 18, 1586 M 7.8)
This earthquake is thought to have occurred in a shallow land location, and to have had an very large size. The earthquake is estimated to have caused seismic ground motion corresponding to a seismic intensity of 6 in JMA scale throughout Gifu Prefecture, western Toyama Prefecture, eastern Shiga Prefecture, and Nagoya (Fig.6-24). There were large slope failure at Hokiwaki in the Hida-Shirakawa Valley. The Kaerigumo Castle was crushed, burying the feudal lord and many of his retainers inside. A total of more than 300 houses were reported that to have been crushed throughout Shirakawa Valley. The Ettchu-Kifune Castle southwest of Takaoka was also crushed, burying the feudal lord and many of his retainers inside. Damage also occurred in Ogaki, Nagashima in Owari, Omi-Nagahama, and Kyoto. Frequent aftershocks of this earthquake continued until January of the next year, and were felt for roughly one year even in Kyoto. There are records of what seems to be liquefaction at the coast in Owari and Ise. Records also indicate that a tsunami may have struck at Ise Bay. Most scientists believe the source region of this earthquake extends from near the Shokawa fault zone, which includes the Miboro fault, to the vicinity of the Adera fault zone [Refer to 6-3 (7)]. There is also the view that an active fault near the interior of Ise Bay including the Yoro-Kuwana-Yokkaichi fault zone moved at the same time. Though research on this earthquake continues, many points remain unclear.