Ibaraki Prefecture (茨城県) — Earthquake Risk & History
Kanto region · Based on HERP official data
Ibaraki is among Japan's most seismically active prefectures, sitting near the triple junction of the Pacific, North American, and Philippine Sea plates. Felt earthquakes are more frequent here than almost anywhere else in Japan, and the 30-year probability of an M6.7+ earthquake off Ibaraki exceeds 85%.
Fault Lines & Seismic Characteristics
Active Faults & Trenches
- Japan Trench
- Off Ibaraki Fault
- Kanuma Fault
Seismic Characteristics
Ibaraki sits near the triple junction of the Pacific, North American, and Philippine Sea plates, producing a complex crustal structure with frequent intra-slab events in addition to trench-boundary earthquakes. Southern Ibaraki (Tsukuba, Toride) would experience Intensity 6+ in a Tokyo Metropolitan Earthquake scenario.
Earthquake History
- M9.0
2011
Great East Japan Earthquake — Intensity 6+ across much of Ibaraki; widespread building damage
📖 Wikipedia - M7.0
2008
Earthquake off Ibaraki — multiple injuries
※ Showing M6+ or Intensity 5+ events. Source: JMA database.
Future Probability — HERP Official Assessment
30-Year Probability (Official Figure)
Long-term evaluation by the Earthquake Research Committee. Ibaraki consistently records the highest number of felt earthquakes in Japan. Activity has continued since 2011, including ongoing aftershocks.
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
- ✅ Ibaraki 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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Why Ibaraki experiences so many earthquakes
Ibaraki sits near Japan's triple-plate junction, making it one of the most seismically active prefectures in the country. Its proximity to the greater Tokyo area raises the risk of widespread impact from any major event.
Source: 방재과학기술연구소 (2022) -
Earthquake safety for Tsukuba and Mito visitors
Ibaraki has the highest frequency of felt earthquakes in Japan, so a minor tremor during your visit is likely. Intensity 3–4 poses no structural risk. If Intensity 5+ occurs, check JMA guidance and suspend outdoor activities.
Source: 이바라키현 방재·위기관리과 (2023) -
Tsunami evacuation at Hitachinaka and Oarai coast
The Ibaraki Pacific coast was hit by tsunami during the 2011 disaster. If strong shaking is felt at Oarai or Hitachinaka, move inland immediately. Tsunami evacuation towers and route markers are installed along the coast.
Source: 이바라키현 방재과·오아라이정 (2022)
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.