Yamagata Prefecture (山形県) — Earthquake Risk & History
Tohoku region · Based on HERP official data
Yamagata's interior mountains make it less exposed than Pacific-coast prefectures, but active faults run through the prefecture. The 2019 Yamagata-oki earthquake (M6.7) reached Intensity 6+ in the Shonai region and triggered a Japan Sea tsunami advisory.
Fault Lines & Seismic Characteristics
Active Faults & Trenches
- Yamagata Basin Fault Zone
- Shonai Plain Fault Zone
Seismic Characteristics
The Yamagata Basin Fault Zone runs north–south through eastern Yamagata City and is capable of an M7.4 earthquake. The Shonai Plain Fault Zone lies near the Japan Sea coast. The 2019 Yamagata-oki earthquake (M6.7) reached Intensity 6+ in the Shonai area and prompted a Japan Sea tsunami advisory.
Earthquake History
- M6.7
2019
Yamagata-oki earthquake — Intensity 6+, injuries in Shonai region, Japan Sea tsunami advisory issued
- M7.0
1894
Shonai earthquake — building collapse, 726 dead
- M7.5
1964
Niigata earthquake — tsunami impact on the Shonai coast of Yamagata
※ Showing M6.5+ 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. Recurrence interval estimated at 1,000–10,000 years, but a direct event beneath Yamagata City would produce Intensity 7.
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
- ✅ Yamagata 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
-
Risk assessment of the Yamagata Basin Fault Zone
An M7.4 earthquake on the Yamagata Basin Fault Zone could cause severe damage in central Yamagata City. Seismic reinforcement of structures directly above the fault is a priority.
Source: 야마가타현 방재과학연구소 (2021) -
Earthquake preparedness for Shonai coast and Yamadera visitors
Yamadera (near Yamagata City) and the Shonai coast (Sakata, Tsuruoka) present different risk profiles. Inland Yamadera faces rockfall risk during strong shaking. The Shonai coast faces the Japan Sea — check for tsunami advisories immediately after any earthquake. Tsunami evacuation towers are installed along the shoreline.
Source: 야마가타현 방재안전과 (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.