Sagami Bay (相模湾) — Earthquake Risk & History
Kanto region · Based on HERP official data
Sagami Bay was the epicenter of the 1923 Great Kanto Earthquake (M7.9, ~100,000 dead). The Sagami Trough runs through the southern bay. A recurrence event would devastate the Tokyo-Kanagawa metropolitan area.
Fault Lines & Seismic Characteristics
Active Faults & Trenches
- Sagami Trough
Sagami Bay was the epicenter of the 1923 Great Kanto Earthquake (M7.9, ~100,000 dead). The Sagami Trough runs through the southern bay. A recurrence event would devastate the Tokyo-Kanagawa metropolitan area.
Earthquake History
- M7.9
1923
Great Kanto Earthquake — epicenter in Sagami Bay; Tokyo and Yokohama devastated; ~100,000 dead
📖 Wikipedia - M8.2
1703
Genroku Kanto earthquake — epicenter in Sagami Bay; tsunami killed thousands
Future Probability — HERP Official Assessment
Long-term probability for this area is available on the HERP official website.
🔗 HERP Official Website →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
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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Sagami Trough major earthquake recurrence cycle
M8-class earthquakes on the Sagami Trough recur on a 200–400 year cycle. About 100 years have passed since the last major event (1923), and experts warn the next recurrence is gradually approaching.
Source: 내각부 중앙방재회의 (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.