4.9

M4.9 Earthquake near Minahasa, Sulawesi, Indonesia — August 26, 2023

2023-08-26 22:45:29 UTC (2023-08-26) · approx. 6:45 AM UTC+8 local

Aftershock of the M5.2 mainshock.

MagnitudeM4.9(mb)
Time22:45 UTC≈ 6:45 AM UTC+8
Depth77.7 kmintermediate depth
Coordinates0.886°, 121.962°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 26, 2023 at 22:45 UTC, a magnitude 4.9 intermediate depth earthquake struck near Minahasa, Sulawesi, Indonesia, at a depth of 77.7 km and coordinates 0.8860°, 121.9616°. This earthquake was detected by 101 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 5.2 mainshock that occurred 1 day ago 152 km W of Gorontalo, 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.

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

Map showing earthquake epicenter at 0.89°, 121.96°

Earthquake Details

Magnitude
4.9 mb
Depth
77.7 km
intermediate depth
Location
0.8860°N
121.9616°E

Technical Information

Event ID
us7000kr8m
Event Type
earthquake
Status
✓ Reviewed
Significance
369
Stations Used
101
Azimuthal Gap
31.0°
Min Station Distance
1.201°
RMS Residual
0.54 sec
Last Updated
2023-10-28 19:15:39 UTC

Common Questions

How strong was the magnitude 4.9 earthquake near Minahasa, Sulawesi, Indonesia?

The magnitude 4.9 earthquake that struck near Minahasa, Sulawesi, Indonesia on August 26, 2023 at 22:45 UTC had a depth of 77.7 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 0.8860°, 121.9616°, which is near Minahasa, Sulawesi, 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 M5.2 one earlier?

No. This magnitude 4.9 earthquake is an aftershock of the larger magnitude 5.2 mainshock that occurred earlier 152 km W of Gorontalo, 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: us7000kr8m). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, August 26, 2023). M4.9 Earthquake near Minahasa, Sulawesi, Indonesia — August 26, 2023. Retrieved October 28, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000kr8m/