M4.2 Earthquake 115 km SSW of Trenggalek, Indonesia — January 31, 2026
2026-01-31 23:27:30 UTC (2026-01-31) · approx. 6:27 AM UTC+7 local
On January 31, 2026 at 23:27 UTC, a magnitude 4.2 intermediate depth earthquake struck 115 km SSW of Trenggalek, Indonesia, at a depth of 84.1 km and coordinates -9.0084°, 111.2412°.
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 5.2 mainshock that occurred 12 days ago 114 km SSW of Trenggalek, Indonesia. 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
111.2412°E
Technical Information
Common Questions
How strong was the magnitude 4.2 earthquake near Trenggalek, Indonesia?
The magnitude 4.2 earthquake that struck 115 km SSW of Trenggalek, Indonesia on January 31, 2026 at 23:27 UTC had a depth of 84.1 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 M5.2 one earlier?
No. This magnitude 4.2 earthquake is an aftershock of the larger magnitude 5.2 mainshock that occurred earlier 114 km SSW of Trenggalek, Indonesia. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
What should I do after an earthquake?
If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks.
Actions
Understanding This Data
Magnitude 4.2 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000s9js). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, January 31, 2026). M4.2 Earthquake 115 km SSW of Trenggalek, Indonesia — January 31, 2026. Retrieved April 23, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000s9js/