4.2

M4.2 Earthquake 42 km NW of Ruteng, IndonesiaAugust 23, 2026

2026-08-23 23:05:29 UTC (2026-08-23) · approx. 7:05 AM UTC+8 local

MagnitudeM4.2(mb)
Time23:05 UTC7:05 AM UTC+8
Depth10.0 kmshallow crustal
Coordinates-8.300°, 120.232°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 23, 2026 at 23:05 UTC, a magnitude 4.2 shallow crustal earthquake struck 42 km NW of Ruteng, Indonesia, at a depth of 10.0 km and coordinates -8.2996°, 120.2320°.

Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 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.

Map showing earthquake epicenter at -8.30°, 120.23°

Earthquake Details

Magnitude
4.2 mb
Depth
10.0 km
shallow crustal
Location
-8.2996°N
120.2320°E

Technical Information

Event ID
us7000tcll
Event Type
earthquake
Status
✓ Reviewed
Significance
271
Stations Used
19
Azimuthal Gap
151.0°
Min Station Distance
3.299°
RMS Residual
0.84 sec
Last Updated
2026-09-16 22:37:58 UTC

Common Questions

How strong was the magnitude 4.2 earthquake near Ruteng, Indonesia?

The magnitude 4.2 earthquake that struck 42 km NW of Ruteng, Indonesia on August 23, 2026 at 23:05 UTC had a depth of 10.0 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 4.2 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 4.2 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.

Understanding This Data

Magnitude 4.2 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000tcll). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, August 23, 2026). M4.2 Earthquake 42 km NW of Ruteng, IndonesiaAugust 23, 2026. Retrieved September 16, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000tcll/