Sanriku Offshore (三陸沖) — Earthquake Risk & History
Tohoku region · Based on HERP official data
The 2011 Great East Japan Earthquake (M9.0) originated here. The Japan Trench produces repeated M7–9 plate-boundary earthquakes — this is one of the world's most seismically active offshore zones. Major tsunamis have struck repeatedly: 1896, 1933, 1960 (Chile), and 2011.
Fault Lines & Seismic Characteristics
Active Faults & Trenches
- Japan Trench
The 2011 Great East Japan Earthquake (M9.0) originated here. The Japan Trench produces repeated M7–9 plate-boundary earthquakes — this is one of the world's most seismically active offshore zones. Major tsunamis have struck repeatedly: 1896, 1933, 1960 (Chile), and 2011.
Earthquake History
- M9.0
2011
Great East Japan Earthquake — Sanriku offshore source zone; 22,000+ dead or missing
📖 Wikipedia - M8.2
1896
Meiji Sanriku earthquake — tsunami killed ~22,000
Future Probability — HERP Official Assessment
Long-term probability for this area is available on the HERP official website.
🔗 HERP Official Website →Traveler Safety Information
Finding Evacuation Shelters
- ✅ Search "避難所" (hinanjo) on Google Maps to find the nearest shelter from your current location
- ✅ Install NHK World or Safety tips (Japan Tourism Agency app) — both send English earthquake alerts
Basic Action Rules
- ✅ At check-in, locate emergency exits and escape routes
- ✅ On strong shaking: protect your head, open a door to secure an exit, do not use elevators
- ✅ Near coasts or rivers: move to high ground immediately — do not wait for a tsunami warning
- ✅ Emergency numbers: Police 110 · Ambulance/Fire 119
- ✅ Contact your embassy in Tokyo for emergency consular assistance
Research & Official Sources AI summary
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Sanriku offshore earthquake recurrence and tsunami risk
M7–9 earthquakes recur repeatedly along the Japan Trench off Sanriku. Aftershock activity has continued since 2011, and M7–8 events remain likely over the coming decades. Sanriku's ria coastline amplifies tsunami run-up significantly.
Source: 도호쿠 대학 지진연구소 (2023)
Related Guides
Seismic characteristics and research summaries on this page are AI-generated from publicly available data by JMA, Cabinet Office, and HERP. Historical earthquake data (year, magnitude, damage) is based on official records, but key figures should always be cross-checked with the latest official sources. This page does not predict future earthquakes.