4.6

M4.6 Earthquake 131 km SE of Itoman, Japan — September 30, 2026

2026-09-30 21:11:57 UTC (1 hour ago) · approx. 6:11 AM UTC+9 local

MagnitudeM4.6(mb)
Time21:11 UTC≈ 6:11 AM UTC+9
Depth10.0 kmshallow crustal
Coordinates25.217°, 128.508°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 30, 2026 at 21:11 UTC, a magnitude 4.6 shallow crustal earthquake struck 131 km SE of Itoman, Japan, at a depth of 10.0 km and coordinates 25.2167°, 128.5077°. This earthquake was detected by 40 seismic stations with good location accuracy and was assigned a USGS significance rating of 326, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 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

Map showing earthquake epicenter at 25.22°, 128.51°

Earthquake Details

Magnitude
4.6 mb
Depth
10.0 km
shallow crustal
Location
25.2167°N
128.5077°E

Technical Information

Event ID
us6000tym9
Event Type
earthquake
Status
✓ Reviewed
Significance
326
Stations Used
40
Azimuthal Gap
96.0°
Min Station Distance
2.526°
RMS Residual
0.55 sec
Last Updated
2026-09-30 21:53:25 UTC

Common Questions

How strong was the magnitude 4.6 earthquake near Itoman, Japan?

The magnitude 4.6 earthquake that struck 131 km SE of Itoman, Japan on September 30, 2026 at 21:11 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 25.2167°, 128.5077°, which is 131 km SE of Itoman, Japan. View all earthquakes in Japan.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 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 4.6 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000tym9). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, September 30, 2026). M4.6 Earthquake 131 km SE of Itoman, Japan — September 30, 2026. Retrieved September 30, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000tym9/