M3.9 Earthquake 55 km NNW of Ruteng, Indonesia — August 25, 2026
2026-08-25 00:37:44 UTC (2026-08-25) · approx. 8:37 AM UTC+8 local
On August 25, 2026 at 00:37 UTC, a magnitude 3.9 shallow crustal earthquake struck 55 km NNW of Ruteng, Indonesia, at a depth of 10.0 km and coordinates -8.1350°, 120.3049°.
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.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.1 mainshock that occurred 5 days ago 50 km N of Ruteng, Indonesia. Since the mainshock, the USGS has recorded 14 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
120.3049°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.9 earthquake near Ruteng, Indonesia?
The magnitude 3.9 earthquake that struck 55 km NNW of Ruteng, Indonesia on August 25, 2026 at 00:37 UTC had a depth of 10.0 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.
Is this the same earthquake as the M5.1 one earlier?
No. This magnitude 3.9 earthquake is an aftershock of the larger magnitude 5.1 mainshock that occurred earlier 50 km N of Ruteng, Indonesia. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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Understanding This Data
Magnitude 3.9 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us7000tdd2). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, August 25, 2026). M3.9 Earthquake 55 km NNW of Ruteng, Indonesia — August 25, 2026. Retrieved September 17, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000tdd2/