Story perspectives

Variable Locking in Nankai Trough Clouds Megaquake Forecasts

7/23/2026

Summary

Story summary

University of Tokyo and the Japanese coastguard reported that the Nankai Trough’s locked zone changes over time, complicating mega-quake forecasts.
The 900 km Nankai Trough lies where the Philippine plate subducts beneath the Eurasian plate.
Researchers analyzed crustal-deformation data from 2013-2023, finding that some trench segments remain continuously locked while others behave more fluidly.
Variable locking adds uncertainty to predictions of future megaquakes and associated tsunamis along the fault line.

1 of 1

Story summary

University of Tokyo and the Japanese coastguard reported that the Nankai Trough’s locked zone changes over time, complicating mega-quake forecasts.
The 900 km Nankai Trough lies where the Philippine plate subducts beneath the Eurasian plate.
Researchers analyzed crustal-deformation data from 2013-2023, finding that some trench segments remain continuously locked while others behave more fluidly.
Variable locking adds uncertainty to predictions of future megaquakes and associated tsunamis along the fault line.