M4.2 Earthquake 44 km NNW of Finschhafen, Papua New Guinea — September 27, 2025
2025-09-27 21:37:17 UTC (2025-09-27) · approx. 7:37 AM UTC+10 local
On September 27, 2025 at 21:37 UTC, a magnitude 4.2 shallow crustal earthquake struck 44 km NNW of Finschhafen, Papua New Guinea, at a depth of 69.6 km and coordinates -6.1681°, 147.7479°.
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.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.1 mainshock that occurred 20 days ago 21 km NW of Finschhafen, Papua New Guinea. Since the mainshock, the USGS has recorded 0 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
147.7479°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.2 earthquake near Finschhafen, Papua New Guinea?
The magnitude 4.2 earthquake that struck 44 km NNW of Finschhafen, Papua New Guinea on September 27, 2025 at 21:37 UTC had a depth of 69.6 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.
Is this the same earthquake as the M5.1 one earlier?
No. This magnitude 4.2 earthquake is an aftershock of the larger magnitude 5.1 mainshock that occurred earlier 21 km NW of Finschhafen, Papua New Guinea. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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Understanding This Data
Magnitude 4.2 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000rhx3). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, September 27, 2025). M4.2 Earthquake 44 km NNW of Finschhafen, Papua New Guinea — September 27, 2025. Retrieved December 11, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000rhx3/