M3.8 Earthquake 40 km NE of Yigo Village, Guam — October 20, 2025
2025-10-20 15:54:54 UTC (2025-10-20) · approx. 1:54 AM UTC+10 local
On October 20, 2025 at 15:54 UTC, a magnitude 3.8 intermediate depth earthquake struck 40 km NE of Yigo Village, Guam, at a depth of 129.9 km and coordinates 13.8303°, 145.1054°.
Physical scale: An earthquake of magnitude 3.8 releases seismic energy equivalent to roughly 7.6 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 252 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 5.3 mainshock that occurred 4 days ago 41 km NNE of Yigo Village, Guam. 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
145.1054°E
Technical Information
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Common Questions
How strong was the magnitude 3.8 earthquake near Yigo Village, Guam?
The magnitude 3.8 earthquake that struck 40 km NE of Yigo Village, Guam on October 20, 2025 at 15:54 UTC had a depth of 129.9 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 3.8 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.3 one earlier?
No. This magnitude 3.8 earthquake is an aftershock of the larger magnitude 5.3 mainshock that occurred earlier 41 km NNE of Yigo Village, Guam. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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Understanding This Data
Magnitude 3.8 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000rmmn). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, October 20, 2025). M3.8 Earthquake 40 km NE of Yigo Village, Guam — October 20, 2025. Retrieved January 9, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000rmmn/