M4.2 Earthquake 38 km NNE of Castlepoint, New Zealand — December 3, 2025
2025-12-03 23:17:42 UTC (2025-12-03) · approx. 11:17 AM UTC+12 local
On December 3, 2025 at 23:17 UTC, a magnitude 4.2 shallow crustal earthquake struck 38 km NNE of Castlepoint, New Zealand, at a depth of 25.9 km and coordinates -40.5830°, 176.3945°.
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.
Earthquake Details
176.3945°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.2 earthquake near Castlepoint, New Zealand?
The magnitude 4.2 earthquake that struck 38 km NNE of Castlepoint, New Zealand on December 3, 2025 at 23:17 UTC had a depth of 25.9 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.
Actions
Understanding This Data
Magnitude 4.2 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000rff4). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, December 3, 2025). M4.2 Earthquake 38 km NNE of Castlepoint, New Zealand — December 3, 2025. Retrieved May 24, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000rff4/