M4.1 Earthquake in the Mariana Islands region — September 30, 2025
2025-09-30 16:46:17 UTC (2025-09-30) · approx. 2:46 AM UTC+10 local
On September 30, 2025 at 16:46 UTC, a magnitude 4.1 deep-focus earthquake struck in the Mariana Islands region, at a depth of 314.4 km and coordinates 21.6082°, 143.0361°.
Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
143.0361°E
Technical Information
Common Questions
How strong was the magnitude 4.1 earthquake in the Mariana Islands region?
The magnitude 4.1 earthquake that struck in the Mariana Islands region on September 30, 2025 at 16:46 UTC had a depth of 314.4 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 4.1 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 4.1 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000riq6). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, September 30, 2025). M4.1 Earthquake in the Mariana Islands region — September 30, 2025. Retrieved May 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000riq6/