A trench survey disclosed that the present fault was activated
at least for the last 2,000 years and specifically between 1,425
and 1,665. It is the Kanbun Earthquake (1,662) that is known as
a historical earthquake which did damage to the neighborhood of
the present fault. By this earthquake were activated the Mikata
Fault in the vicinity of the Mikata Five Lakes (Mikata-goko),
the northern part of the Hanaore Fault on the west bank of the
lakes, and part of the Biwa Lake West-Bank Fault System. The present
fault was highly probably activated together with these faults.
The vertical slips accumulated for the last 20,000 years (about
2 m) and produced by the latest activity (about 50 cm) enable
to estimate the reccurrence interval at 5,000 to 6,500 years.
Nosaka Fault exposed on a trench wall.
Sketch of the western wall of Trench B
Figures in the sketch show14C age (year BP) revised
by a value of δ13C, respectively.
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Map Findings of Active Fault
Survey Projects
