Fig. 5

Schematic diagram showing that the seafloor lineament across the B–C boundary off the Kii Peninsula was produced by simultaneous (e.g., the 1707 Hoei earthquake) splay fault slips. Individual (e.g., the 1944 Tonankai or 1946 Nankai events) splay fault slips could help the growth of the seafloor lineament. Very low-frequency earthquakes and tremors around the splay fault are marked by red stars.