4.2

M4.2 Earthquake in the Bonin Islands, Japan regionOctober 1, 2025

2025-10-01 23:02:50 UTC (2025-10-01) · approx. 8:02 AM UTC+9 local

MagnitudeM4.2(mb)
Time23:02 UTC8:02 AM UTC+9
Depth429.7 kmdeep-focus
Coordinates28.400°, 139.530°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 1, 2025 at 23:02 UTC, a magnitude 4.2 deep-focus earthquake struck in the Bonin Islands, Japan region, at a depth of 429.7 km and coordinates 28.4002°, 139.5299°.

Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 28.40°, 139.53°

Earthquake Details

Magnitude
4.2 mb
Depth
429.7 km
deep-focus
Location
28.4002°N
139.5299°E

Technical Information

Event ID
us6000re43
Event Type
earthquake
Status
✓ Reviewed
Significance
271
Stations Used
109
Azimuthal Gap
67.0°
Min Station Distance
2.687°
RMS Residual
0.49 sec
Last Updated
2025-12-19 22:49:40 UTC

Common Questions

How strong was the magnitude 4.2 earthquake in the Bonin Islands, Japan region?

The magnitude 4.2 earthquake that struck in the Bonin Islands, Japan region on October 1, 2025 at 23:02 UTC had a depth of 429.7 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 4.2 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: us6000re43). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, October 1, 2025). M4.2 Earthquake in the Bonin Islands, Japan regionOctober 1, 2025. Retrieved May 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000re43/