4.0

M4.0 Earthquake 97 km S of Koshima, JapanApril 10, 2026

2026-04-10 21:28:08 UTC (2026-04-10) · approx. 6:28 AM UTC+9 local

MagnitudeM4.0(mb)
Time21:28 UTC6:28 AM UTC+9
Depth42.2 kmshallow crustal
Coordinates29.361°, 130.623°
Felt byNo felt reports
Status✓ Reviewed by USGS

On April 10, 2026 at 21:28 UTC, a magnitude 4.0 shallow crustal earthquake struck 97 km S of Koshima, Japan, at a depth of 42.2 km and coordinates 29.3607°, 130.6234°.

Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 29.36°, 130.62°

Earthquake Details

Magnitude
4.0 mb
Depth
42.2 km
shallow crustal
Location
29.3607°N
130.6234°E

Technical Information

Event ID
us6000srme
Event Type
earthquake
Status
✓ Reviewed
Significance
246
Stations Used
14
Azimuthal Gap
139.0°
Min Station Distance
2.147°
RMS Residual
0.40 sec
Last Updated
2026-05-01 03:53:37 UTC

Common Questions

How strong was the magnitude 4.0 earthquake near Koshima, Japan?

The magnitude 4.0 earthquake that struck 97 km S of Koshima, Japan on April 10, 2026 at 21:28 UTC had a depth of 42.2 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 4.0 earthquakes can continue for several days and gradually diminish over time.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.

Authoritative source: USGS event page (event ID: us6000srme). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, April 10, 2026). M4.0 Earthquake 97 km S of Koshima, JapanApril 10, 2026. Retrieved May 20, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000srme/