M4.9 Earthquake 88 km N of Ruteng, Indonesia — August 21, 2026
2026-08-21 08:14:00 UTC (1 hour ago) · approx. 4:14 PM UTC+8 local
Aftershock of the M5.3 mainshock.
On August 21, 2026 at 08:14 UTC, a magnitude 4.9 shallow crustal earthquake struck 88 km N of Ruteng, Indonesia, at a depth of 36.6 km and coordinates -7.8156°, 120.5155°. This earthquake was detected by 31 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 369, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 km — 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 23 hours ago 48 km NNE of Ruteng, Indonesia. Since the mainshock, the USGS has recorded 13 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
The epicenter is located in Indonesia, a region characterized by the convergence of the Indo-Australian, Eurasian, and Philippine Sea plates, forming the Sunda-Banda arc system. The nearest mapped fault system is the Sunda megathrust. View all earthquakes in Indonesia.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
120.5155°E
Technical Information
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Common Questions
How strong was the magnitude 4.9 earthquake near Ruteng, Indonesia?
The magnitude 4.9 earthquake that struck 88 km N of Ruteng, Indonesia on August 21, 2026 at 08:14 UTC had a depth of 36.6 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -7.8156°, 120.5155°, which is 88 km N of Ruteng, Indonesia. View all earthquakes in Indonesia.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 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 4.9 earthquake is an aftershock of the larger magnitude 5.3 mainshock that occurred earlier 48 km NNE of Ruteng, Indonesia. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Has Indonesia had earthquakes this big before?
The largest recorded earthquake in Indonesia was the M9.1 Indian Ocean earthquake of December 26, 2004. Today's magnitude 4.9 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000tmej). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, August 21, 2026). M4.9 Earthquake 88 km N of Ruteng, Indonesia — August 21, 2026. Retrieved August 21, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000tmej/