Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

The segments of this large WNW-ESENoto Offshore fault zone are not well characterized, and slip rate is estimated around 0.3 mm/yr. The NP experienced another modern strong earthquake (M6.9) in 2007, caused by another N60°E striking reverse fault off the western coast (Monzen- oki segment, not shown in Figure 1). ENVIRONMENTAL EFFECTS A local bathymetric survey was conducted at the western tip of the fault off the northern coast, after the shock. Thanks to a pre- existing campaign, the authors could document a 2 (minimum) km-long and 3 m-high coseismic scarp corresponding to the primary surface rupture, several hundred meters off the coastline (Figure 1, Off label) (Japan Coast Guard, 2024). Onshore surface rupture evidence was identified first by aerial photos first by the Japanese teams. After checking in the field, we could recognize in the Wakayama valley (Wak label) a series of north and south- verging scarps with evidence of contraction (Figure 2). We interpret this set of deformation features as secondary rupture evidence, possibly corresponding to flexural slip along the limbs of the Neogene Okada anticline. Fig. 1: Location of the major sites visited during the one-week field survey. Localities in yellow, major sites of interest in red. The so-called Noto Peninsula Offshore fault zone is only indicative and gathers a series of segments described in the AIST database.