Late Quaternary activity of the Miyashiro fault along the western margin of the Nobi Plain, central Japan

Abstract

The Miyashiro fault is a reverse fault extending in the direction of NW to SE for 7 km along the western margin of the Nobi Plain, central Japan. This fault appears to have played an important role in separating the Nangu Mountains from the Nobi Plain during the Late Quaternary. We studied tectonic geomorphic features along the Miyashiro fault where it crosses the Himori fan in Tarui Town.
The latest faulting event of the Miyashiro fault oc c urred after 1,730 y. B. P., with larger than 1.5 m vertical offset. The vertical slip rate of this fault is as high as 0.5-0.6 mm/yr during the past 15,000-20,000 years. If the average offset during a single earthquake is 1.5 m or larger, the average recurrence interval of earthquake might be 2,500-3,000 years or longer.