Okinawa Prefecture (沖縄県) — Earthquake Risk & History
Okinawa region · Based on HERP official data
Okinawa faces the Ryukyu Trench. The April 2024 Taiwan earthquake (M7.4) triggered tsunami warnings for Ishigaki and advisories for the main island. The 1771 Yaeyama earthquake produced Japan's largest pre-modern tsunami (~12,000 dead). Typhoon risk from June to October compounds earthquake hazards.
Fault Lines & Seismic Characteristics
Active Faults & Trenches
- Ryukyu Trench
- Okinawa Trough
- Taiwan–Philippine Trench (distant)
Seismic Characteristics
The Ryukyu Trench runs east of Okinawa, where the Philippine Sea Plate subducts under the Eurasian Plate. The Okinawa Trough (East China Sea) is an active back-arc basin. The 1771 Yaeyama earthquake produced a massive tsunami that devastated the Yaeyama and Miyako Islands. Taiwan and Philippines earthquakes can also send tsunamis toward Okinawa.
Earthquake History
- M7.4
2024
Taiwan Hualien earthquake — tsunami warning issued for Ishigaki; advisory for Okinawa main island
- M7.2
2010
Okinawa Honto Kinkai earthquake — Intensity 4–5 observed in Okinawa
- M7.4
1771
Yaeyama earthquake — Japan's largest pre-modern tsunami; ~12,000 dead or missing (catastrophic damage to Yaeyama and Miyako Islands)
※ Showing Intensity 3+ or tsunami-generating historical events. The 1771 Yaeyama earthquake is based on historical documentary records. Source: JMA database and University of the Ryukyus historical research.
Future Probability — HERP Official Assessment
30-Year Probability (Official Figure)
Earthquake Research Committee assessment ongoing. The 1771 Yaeyama tsunami recurrence potential is under study. Taiwan and Philippines earthquakes also carry tsunami risk for Okinawa. Also check typhoon information (June–October) when visiting.
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
- ✅ Okinawa 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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Ryukyu Trench earthquake and Okinawa tsunami risk
The Ryukyu Trench has historically produced M7–8 earthquakes. Okinawa's low-lying topography and complex coastline amplify tsunami damage. The 2024 Taiwan earthquake confirmed this risk remains active.
Source: 내각부·오키나와현 (2024) -
Okinawa disaster risks by season
Okinawa carries typhoon risk from June to October and year-round tsunami risk from the Ryukyu Trench. Before visiting during typhoon season, check JMA typhoon information and flight status. Travel insurance with cancellation coverage is recommended.
Source: 오키나와현 관광청 (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.