4.1

M4.1 Earthquake 37 km NE of Kuji, JapanNovember 13, 2025

2025-11-13 21:23:35 UTC (2025-11-13) · approx. 6:23 AM UTC+9 local

MagnitudeM4.1(mb)
Time21:23 UTC6:23 AM UTC+9
Depth60.0 kmshallow crustal
Coordinates40.388°, 142.130°
Felt byNo felt reports
Status✓ Reviewed by USGS

On November 13, 2025 at 21:23 UTC, a magnitude 4.1 shallow crustal earthquake struck 37 km NE of Kuji, Japan, at a depth of 60.0 km and coordinates 40.3877°, 142.1298°.

Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 m — a useful intuition for the size of the slip patch on the fault.

This earthquake is part of an ongoing aftershock sequence following the magnitude 6.0 mainshock that occurred 13 days ago 49 km E of Noda, Japan. Since the mainshock, the USGS has recorded 6 aftershocks in this area. Aftershock activity is expected to continue for weeks to months as stresses on surrounding faults redistribute.

Map showing earthquake epicenter at 40.39°, 142.13°

Earthquake Details

Magnitude
4.1 mb
Depth
60.0 km
shallow crustal
Location
40.3877°N
142.1298°E

Technical Information

Event ID
us7000rf32
Event Type
earthquake
Status
✓ Reviewed
Significance
259
Stations Used
19
Azimuthal Gap
183.0°
Min Station Distance
0.905°
RMS Residual
0.53 sec
Last Updated
2026-02-10 15:55:17 UTC

Common Questions

How strong was the magnitude 4.1 earthquake near Kuji, Japan?

The magnitude 4.1 earthquake that struck 37 km NE of Kuji, Japan on November 13, 2025 at 21:23 UTC had a depth of 60.0 km. For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.1 earthquakes can continue for several days and gradually diminish over time.

Is this the same earthquake as the M6.0 one earlier?

No. This magnitude 4.1 earthquake is an aftershock of the larger magnitude 6.0 mainshock that occurred earlier 49 km E of Noda, Japan. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

Understanding This Data

Magnitude 4.1 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000rf32). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, November 13, 2025). M4.1 Earthquake 37 km NE of Kuji, JapanNovember 13, 2025. Retrieved February 10, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000rf32/