4.2

M4.2 Earthquake south of the Kermadec IslandsOctober 4, 2025

2025-10-04 18:05:22 UTC (2025-10-04) · approx. 6:05 AM UTC-12 local

MagnitudeM4.2(mb)
Time18:05 UTC6:05 AM UTC-12
Depth41.3 kmshallow crustal
Coordinates-33.885°, -179.206°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 4, 2025 at 18:05 UTC, a magnitude 4.2 shallow crustal earthquake struck south of the Kermadec Islands, at a depth of 41.3 km and coordinates -33.8851°, -179.2063°.

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 -33.89°, -179.21°

Earthquake Details

Magnitude
4.2 mb
Depth
41.3 km
shallow crustal
Location
-33.8851°N
-179.2063°E

Technical Information

Event ID
us6000rj7a
Event Type
earthquake
Status
✓ Reviewed
Significance
271
Stations Used
14
Azimuthal Gap
263.0°
Min Station Distance
4.190°
RMS Residual
0.33 sec
Last Updated
2025-12-19 22:50:43 UTC

Common Questions

How strong was the magnitude 4.2 earthquake south of the Kermadec Islands?

The magnitude 4.2 earthquake that struck south of the Kermadec Islands on October 4, 2025 at 18:05 UTC had a depth of 41.3 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: us6000rj7a). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, October 4, 2025). M4.2 Earthquake south of the Kermadec IslandsOctober 4, 2025. Retrieved May 27, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000rj7a/