Chiba Prefecture (千葉県) — Earthquake Risk & History
Kanto region · Based on HERP official data
Chiba faces multiple serious earthquake scenarios: a Tokyo Metropolitan Earthquake, a Boso offshore earthquake, and broader Tokai/Nankai-linked events. Tokyo Bay coastal reclaimed land carries extreme liquefaction risk. The 2011 earthquake demonstrated the scale of potential damage.
Fault Lines & Seismic Characteristics
Active Faults & Trenches
- E off Boso Peninsula Fault
- Kanto Fault System
- Tokyo Bay Fault
Seismic Characteristics
Chiba's Boso Peninsula sits at the intersection of the Pacific, North American, and Philippine Sea plates. Reclaimed coastal land in Tokyo Bay (Urayasu, Makuhari) carries extreme liquefaction risk. A slow-slip phenomenon off the Boso coast has been documented on a several-year cycle, which research suggests could contribute to earthquake triggering.
Earthquake History
- M9.0
2011
Great East Japan Earthquake — large-scale liquefaction in Urayasu City; widespread damage across northwestern Chiba
📖 Wikipedia - M6.7
1987
Earthquake off eastern Chiba — building damage in Tokyo and Chiba
※ Showing M6+ or Intensity 5+ events. Source: JMA database.
Future Probability — HERP Official Assessment
30-Year Probability (Official Figure)
Cabinet Office Tokyo Metropolitan Earthquake Working Group 2022 evaluation. Tokyo Bay reclaimed land liquefaction risk is a key additional concern.
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
- ✅ Chiba 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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Boso Peninsula slow-slip and earthquake risk
A slow-slip phenomenon has been documented off the Boso coast on a several-year cycle. Research indicates this slow stress transfer could contribute to triggering larger earthquakes.
Source: 국립연구개발법인 방재과학기술연구소 (2023) -
Liquefaction at Urayasu and Makuhari — visitor safety near Tokyo Disney Resort
During the 2011 earthquake, Urayasu City (adjacent to Tokyo Disney Resort) suffered widespread road and residential liquefaction. Ground improvement works followed, but the risk remains on reclaimed land. Tokyo Disneyland and DisneySea have solid seismic design, but be aware of liquefaction risks on surrounding roads and at nearby accommodation.
Source: 우라야스시 방재과·국토지리원 (2022) -
Earthquake preparedness on the southern Boso coast
The southern Boso coast (Shirahama, Nojimamisaki) faces the Pacific — tsunami awareness is essential. The sea off eastern Boso has repeatedly generated earthquakes. If staying near the coast, confirm tsunami evacuation routes in advance.
Source: 지바현 방재·방범과 (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.