Osaka Prefecture (大阪府) — Earthquake Risk & History
Kinki region · Based on HERP official data
Osaka faces a dual threat: the Uemachi Fault Zone's M7.5 direct earthquake and the Nankai Trough megaquake (70–80%). The 2018 Osaka North earthquake (M6.1) demonstrated how even a moderate event can paralyze Japan's second-largest city.
Fault Lines & Seismic Characteristics
Active Faults & Trenches
- Uemachi Fault Zone
- Ikoma Fault Zone
- Nankai Trough (indirect)
Seismic Characteristics
The Uemachi Fault Zone runs north–south through central Osaka — Osaka Castle sits directly on this fault. A Nankai Trough earthquake would send tsunami into Osaka Bay and flood the city's extensive underground network of subway stations and underground shopping malls. The 2018 Osaka North earthquake (M6.1) originated on a different fault from Uemachi.
Earthquake History
- M6.1
2018
Osaka North earthquake — Intensity 6- and 6+; 6 dead; Tokaido Shinkansen and Hankyu halted; factories shut down
- M8.4
1854
Ansei Nankai earthquake — tsunami entered Osaka Bay; damage to vessels and coastal infrastructure
- M7.5
1596
Keicho Fushimi earthquake — Osaka Castle stone walls collapsed; widespread damage across Kyoto and Osaka
※ Showing M6+ or historically significant events. Source: JMA database and historical earthquake records.
Future Probability — HERP Official Assessment
30-Year Probability (Official Figure)
Earthquake Research Committee 2023 assessment. An M7.5 Uemachi Fault event is projected to cause Intensity 7 downtown and up to 42,000 deaths (Osaka Prefecture Disaster Prevention Council 2022).
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
- ✅ Osaka 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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Projected damage from a Uemachi Fault earthquake
An M7.5 Uemachi Fault earthquake could cause Intensity 7 in central Osaka, projecting up to 42,000 deaths and 560,000 buildings destroyed or burned (worst-case). A simultaneous Nankai Trough event would amplify damage further.
Source: 오사카부 방재회의 (2022) -
Osaka lowland tsunami and flooding compound risk
Osaka's low-lying coastal areas (including below-sea-level zones) face combined risk from Nankai Trough tsunami and river flooding. Underground spaces — subways, underground malls — are particularly vulnerable to inundation.
Source: 국토교통성 근기지방정비국 (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.