M4.1 Earthquake 261 km N of Saipan, Northern Mariana Islands — August 20, 2025
2025-08-20 23:14:23 UTC (2025-08-20) · approx. 9:14 AM UTC+10 local
On August 20, 2025 at 23:14 UTC, a magnitude 4.1 deep-focus earthquake struck 261 km N of Saipan, Northern Mariana Islands, at a depth of 351.7 km and coordinates 17.5340°, 145.3159°.
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
145.3159°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.1 earthquake near Saipan, Northern Mariana Islands?
The magnitude 4.1 earthquake that struck 261 km N of Saipan, Northern Mariana Islands on August 20, 2025 at 23:14 UTC had a depth of 351.7 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.
Actions
Understanding This Data
Magnitude 4.1 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000qwca). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, August 20, 2025). M4.1 Earthquake 261 km N of Saipan, Northern Mariana Islands — August 20, 2025. Retrieved November 12, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000qwca/