Hiroshima Prefecture (広島県) — Earthquake Risk & History
Chugoku region · Based on HERP official data
Hiroshima faces the Seto Inland Sea and receives indirect Nankai Trough risk. The island-studded coastline partially attenuates tsunami, but bay geometry can concentrate waves. Mountain areas carry significant landslide risk.
Fault Lines & Seismic Characteristics
Active Faults & Trenches
- Jozan Fault Zone
- Nagato–Iwakuni Fault
Seismic Characteristics
Hiroshima Prefecture faces the Seto Inland Sea and lies in the indirect influence zone of the Nankai Trough. The Seto Inland Sea's islands partially attenuate tsunami, but bay geometry can concentrate waves at specific points. The Chugoku Mountains carry significant landslide risk.
Earthquake History
- M7.2
1905
Geisuinada earthquake — damage around Hiroshima
※ Showing M6+ or historically significant events. Source: JMA database.
Future Probability — HERP Official Assessment
30-Year Probability (Official Figure)
Long-term evaluation by the Earthquake Research Committee. Hiroshima city faces low direct fault risk but would experience Intensity 5–6 shaking and potentially a weakened tsunami in a Nankai Trough event.
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
- ✅ Hiroshima Prefecture official disaster prevention page (Japanese) — includes shelter maps
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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Tsunami attenuation by Seto Inland Sea islands
The islands of the Seto Inland Sea partially attenuate tsunami from Nankai Trough events, but bay shapes can concentrate waves at specific coastal points, creating uneven damage.
Source: 히로시마대학 방재연구소 (2021) -
Earthquake safety for Hiroshima City and Miyajima visitors
Hiroshima city is built on a river delta — a weakened Nankai Trough tsunami could reach the coast via Hiroshima Bay. Miyajima (Itsukushima Shrine) is on an island — if a major earthquake strikes while you're there, ferry service may suspend, making same-day return difficult. Know the island's evacuation sites before you visit.
Source: 히로시마현 방재과·히로시마시 (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.