May 8, 1847 Earthquake: Zenkoji, Nagano, Japan

Reference #1068 lists earthquake on May 8, 1847, 37 N, 138 E, 12,000 deaths, 34,000 houses destroyed.

Reference #1002 lists earthquake on May 8, 1847, in Zenkoji, magnitude 7.4, 12,000 deaths.

Reference #1006 lists earthquake on May 8, 1847, 12,000 dead, 34,000 houses destroyed.

Reference #1055 lists earthquake on May 8, 1847, in Shinano, Japan, intensity III which corresponds to an earthquake which destroyed towns and devastated districts.

Reference #1051 lists earthquake on May 8, 1847, in matsumoto, Japan, 8,600 deaths.

Reference #1136 lists earthquake on May 8, 1847, 36 N, 138 E, at Zenkoji (Nagano), 12,000 deaths, 34,000 houses destroyed. 2.4 m vertical displacement on an 8 km long fault. A large number of landslides occurred.

Reference #1097 describes the earthquake on May 8, 1847:

This earthquake, at about 9.30 on the evening of May 8,

originated near Zenkozi and laid waste the northern part of Sisano and the western part of Etigo; throwing down as many as 30,000 houses besides an additional 13,000 which were partially leveled. It came in the midst of a religious service at the Zenkozi Temple so that thousands of devout worshippers were among the victims, besides some 8,500 others that met the same fate.

Fires promptly broke out in the towns of Zenkozi, Iiyama, Inariyama, Sinmati, etc., and practically completed the destruction. In Zenkozi out of a total of 2,236 dwellings only 142 were left unscathed by fire or earthquake.

The most characteristic phenomenon in connection with this earthquake, however, was the extraordinary large number of landslides that took place and the consequences which they brought about. It is said that the number altogether did not fall short of 43,000, hence small wonder that many villages were buried under falling debris. The largest of these occurred between Komatubara and Sinmati and completely blocked the course of the River Saikawa, with the result that in the course of a week or two there came into existence a temporary lake measuring 28km by 4km at its widest part. This new lake however was not destined to remain for long, for at the end of 19 days the blocking dam gave way and let loose the enormous quantity of water, giving rise to a terrible inundation which carried destruction before it, sweeping everything off both banks of the lower river course. Some 4,500 houses and 35 persons were thus swept away.

The topographical changes, with which we are most concerned in connection with our studies, duly appeared in the form of a conspicuous fault line. It was in the meizoseismal area with a trend SW-NE and extended for about 8 km. At a point near Nagano the NW side of the fault had arisen as much as 2.4 meters relatively to the opposite side.