M3.9 Earthquake in the Maug Islands region, Northern Mariana Islands — August 28, 2025
2025-08-28 15:50:49 UTC (2025-08-28) · approx. 1:50 AM UTC+10 local
On August 28, 2025 at 15:50 UTC, a magnitude 3.9 intermediate depth earthquake struck in the Maug Islands region, Northern Mariana Islands, at a depth of 186.8 km and coordinates 20.4797°, 144.8663°.
Physical scale: An earthquake of magnitude 3.9 releases seismic energy equivalent to roughly 11 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 296 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
144.8663°E
Technical Information
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Common Questions
How strong was the magnitude 3.9 earthquake in the Maug Islands region, Northern Mariana Islands?
The magnitude 3.9 earthquake that struck in the Maug Islands region, Northern Mariana Islands on August 28, 2025 at 15:50 UTC had a depth of 186.8 km. For context, this was a minor earthquake typically detected only by instruments.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.9 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.9 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000rcaz). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, August 28, 2025). M3.9 Earthquake in the Maug Islands region, Northern Mariana Islands — August 28, 2025. Retrieved November 19, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000rcaz/