M4.5 Earthquake 59 km SE of Koseda, Japan — August 4, 2026
2026-08-04 20:01:17 UTC (2026-08-04) · approx. 5:01 AM UTC+9 local
On August 4, 2026 at 20:01 UTC, a magnitude 4.5 shallow crustal earthquake struck 59 km SE of Koseda, Japan, at a depth of 10.0 km and coordinates 30.0665°, 131.1461°. This earthquake was detected by 38 seismic stations with good location accuracy and was assigned a USGS significance rating of 312, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.5 releases seismic energy equivalent to roughly 85 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 767 m — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Japan, a region characterized by the intersection of four tectonic plates — Pacific, Philippine Sea, Eurasian, and North American — creating multiple subduction zones. The nearest mapped fault system is the Japan Trench. View all earthquakes in Japan.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
131.1461°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.5 earthquake near Koseda, Japan?
The magnitude 4.5 earthquake that struck 59 km SE of Koseda, Japan on August 4, 2026 at 20:01 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 30.0665°, 131.1461°, which is 59 km SE of Koseda, Japan. View all earthquakes in Japan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.5 earthquakes can continue for several days and gradually diminish over time.
Has Japan had earthquakes this big before?
The largest recorded earthquake in Japan was the M9.1 Tohoku earthquake of March 11, 2011. Today's magnitude 4.5 event is significantly smaller than that historical record.
Actions
Location
Authoritative source: USGS event page (event ID: us6000tj0d). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, August 4, 2026). M4.5 Earthquake 59 km SE of Koseda, Japan — August 4, 2026. Retrieved August 20, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000tj0d/