● Philippine Trench / Taiwan — Philippine Sea Plate subduction
Length: ~1,400 km, depth >10,000 m
Hazard: M7–8 interplate earthquakes, tsunami risk
● Nankai Trough / Ryukyu Arc — Eurasian/Philippine interface
M9 scenario: Full Nankai rupture est. 270,000+ fatalities
Taiwan: complex triple-junction — Luzon / Ryukyu / Philippine convergence