A great capital on three plates
Tokyo sits where three tectonic plates meet.
The Kanto region around Tokyo is one of the most tectonically complex places on Earth, where the Pacific, Philippine Sea and continental plates converge. The Sagami Trough just offshore produced the 1923 Great Kanto earthquake, and it recurs over roughly a couple of centuries.
What is happening at Tokyo and the Sagami Trough
Beneath greater Tokyo, two oceanic plates plunge under the landmass at different angles, stacking up faults at several depths. That makes for frequent quakes and a genuinely three-dimensional hazard.
The Sagami Trough offshore is the source of the great Kanto earthquakes. The 1923 event is the benchmark disaster the modern city is engineered against, and the same boundary continues to load.
The hazard record here
THE RECORD HERE
A magnitude 8.0 earthquake struck here in 1923.
Live figures from the QuakeMate hazard API - USGS earthquake catalog, NOAA tsunami database and published recurrence estimates. Some fields are blank where there is no record.
Recent earthquakes at Tokyo and the Sagami Trough
- 3.3NEAR EAST COAST OF HONSHU, JAPAN1 hour ago · 01/08/2026, 09:22:30 · 20 km deep
- 3.1EASTERN HONSHU, JAPAN1 week ago · 20/07/2026, 17:23:30 · 20 km deep
- 3.0EASTERN HONSHU, JAPAN2 weeks ago · 16/07/2026, 16:10:30 · 50 km deep
- 4.71 km WNW of Sōsa, Japan2 weeks ago · 16/07/2026, 00:01:08 · 60 km deep
- 4.7NEAR EAST COAST OF HONSHU, JAPAN2 weeks ago · 16/07/2026, 00:01:30 · 60 km deep
- 3.0NEAR EAST COAST OF HONSHU, JAPAN2 weeks ago · 13/07/2026, 06:32:30 · 50 km deep
22 more earthquakes at Tokyo and the Sagami Trough
Open the QuakeMate app to see every quake here, sorted and mapped - plus real-time alerts when a new one strikes.
Notable events
4.8Recent2026M4.8 - 32 km E of Uonuma, Japan4 weeks ago · tap for full data1923
The M7.9 Great Kanto earthquake and fires destroyed much of Tokyo and Yokohama.
2011
The M9.0 Tohoku earthquake shook Tokyo hard from far to the northeast.
What scientists watch
Japan blankets the Kanto region with seismometers and runs a nationwide early-warning system that can alert Tokyo before strong shaking arrives.
Staying ahead of it
In a city of tens of millions, even seconds of warning let trains slow and people brace - QuakeMate keeps the alert and the record together.
Get QuakeMate freeGet warned before the next one at Tokyo and the Sagami Trough.
QuakeMate sends a push the instant the ground moves - plus tsunami and volcano alerts. Free to download.
Tokyo and the Sagami Trough: common questions
Why is Tokyo at such high earthquake risk?
It sits at a junction of three plates, with faults at several depths beneath it and the great-quake-producing Sagami Trough just offshore. Japanese agencies plan for a major Tokyo-area earthquake within the coming decades.
What was the Great Kanto earthquake?
A magnitude 7.9 earthquake in 1923 on the Sagami Trough that, with the fires that followed, became one of the deadliest disasters in Japanese history and shaped the city’s modern preparedness.
Related hazard zones
Earthquake data via the QuakeMate API (USGS, EMSC and regional agencies). Historical notes summarise well-established events; magnitudes and dates follow the published record. Live figures may be revised.