4.1

M4.1 Earthquake 166 km SE of Sarangani, PhilippinesOctober 11, 2023

2023-10-11 18:12:32 UTC (2023-10-11) · approx. 2:12 AM UTC+8 local

MagnitudeM4.1(mb)
Time18:12 UTC2:12 AM UTC+8
Depth40.0 kmshallow crustal
Coordinates4.225°, 126.393°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 11, 2023 at 18:12 UTC, a magnitude 4.1 shallow crustal earthquake struck 166 km SE of Sarangani, Philippines, at a depth of 40.0 km and coordinates 4.2250°, 126.3929°.

Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 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 5.0 mainshock that occurred 13 days ago 205 km SE of Sarangani, Philippines. Since the mainshock, the USGS has recorded 2 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 4.22°, 126.39°

Earthquake Details

Magnitude
4.1 mb
Depth
40.0 km
shallow crustal
Location
4.2250°N
126.3929°E

Technical Information

Event ID
us6000lg5m
Event Type
earthquake
Status
✓ Reviewed
Significance
259
Stations Used
33
Azimuthal Gap
129.0°
Min Station Distance
3.565°
RMS Residual
0.63 sec
Last Updated
2023-12-16 22:13:09 UTC

Common Questions

How strong was the magnitude 4.1 earthquake near Sarangani, Philippines?

The magnitude 4.1 earthquake that struck 166 km SE of Sarangani, Philippines on October 11, 2023 at 18:12 UTC had a depth of 40.0 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 4.1 earthquakes can continue for several days and gradually diminish over time.

Is this the same earthquake as the M5.0 one earlier?

No. This magnitude 4.1 earthquake is an aftershock of the larger magnitude 5.0 mainshock that occurred earlier 205 km SE of Sarangani, Philippines. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

Understanding This Data

Magnitude 4.1 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000lg5m). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, October 11, 2023). M4.1 Earthquake 166 km SE of Sarangani, PhilippinesOctober 11, 2023. Retrieved December 16, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lg5m/