Idosawa Fault

It has since been compartmentalized into separate striations near Tabito-cho west of Iwaki city.

The northernmost and largest of the faultlines, the North Fault, was identified in 2009 and extends roughly 24 km (15 mi) from the southeast to the northwest (N45˚W).

To its southwest, two parallel faultlines, the East and Shionihara faults, extend from the south-southeast to the north-northwest (N10˚W).

The westernmost of the two, the Shionihara Fault lies near Tabito-cho and borders the small village of Shionohira, after which it was named.

[2] The main structural trend is north-northwest–south-southeast, with sinking observed only to the south on the east side of the fault.