Overview
- JMA will start operational use of N‑net coastal tsunami observations at noon local time on November 20, 2025.
- The number of offshore tsunami observation points published in warnings will rise from 250 to 268 with the coastal inputs.
- NIED installed seafloor seismometers and pressure gauges along previously under‑monitored areas from off Kochi to Hyuga‑nada/Miyazaki.
- Combined use of N‑net’s offshore system, already in service since November 21, 2024, and the coastal system is expected to enable detection up to about 20 minutes earlier.
- JR Hokkaido has adopted a policy allowing people to cross closed level crossings during tsunami evacuations, citing blockages seen during this summer’s Kamchatka‑area warning, and plans to brief Pacific‑coast municipalities on November 17.