M4.6 Earthquake 203 km N of Madang, Papua New Guinea — October 28, 2025
2025-10-28 18:07:21 UTC (2025-10-28) · approx. 4:07 AM UTC+10 local
On October 28, 2025 at 18:07 UTC, a magnitude 4.6 shallow crustal earthquake struck 203 km N of Madang, Papua New Guinea, at a depth of 10.0 km and coordinates -3.3915°, 145.9476°. This earthquake was detected by 22 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 326, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 m — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Papua New Guinea, a region characterized by the collision and subduction of the Pacific, Australian, and Solomon Sea plates. View all earthquakes in Papua New Guinea.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
145.9476°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.6 earthquake near Madang, Papua New Guinea?
The magnitude 4.6 earthquake that struck 203 km N of Madang, Papua New Guinea on October 28, 2025 at 18:07 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -3.3915°, 145.9476°, which is 203 km N of Madang, Papua New Guinea. View all earthquakes in Papua New Guinea.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 earthquakes can continue for several days and gradually diminish over time.
Has Papua New Guinea had earthquakes this big before?
The largest recorded earthquake in Papua New Guinea was the M8.0 New Britain earthquake of July 18, 1971. Today's magnitude 4.6 event is significantly smaller than that historical record.
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: us6000rk0y). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, October 28, 2025). M4.6 Earthquake 203 km N of Madang, Papua New Guinea — October 28, 2025. Retrieved May 26, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000rk0y/