4.1

M4.1 Earthquake 21 km ESE of Looc, PhilippinesJuly 29, 2026

2026-07-29 00:23:24 UTC (2026-07-29) · approx. 8:23 AM UTC+8 local

MagnitudeM4.1(mb)
Time00:23 UTC8:23 AM UTC+8
Depth199.4 kmintermediate depth
Coordinates13.669°, 120.444°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 29, 2026 at 00:23 UTC, a magnitude 4.1 intermediate depth earthquake struck 21 km ESE of Looc, Philippines, at a depth of 199.4 km and coordinates 13.6688°, 120.4443°.

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 12 days ago 7 km NW of Cabacao, Philippines. 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.

Map showing earthquake epicenter at 13.67°, 120.44°

Earthquake Details

Magnitude
4.1 mb
Depth
199.4 km
intermediate depth
Location
13.6688°N
120.4443°E

Technical Information

Event ID
us6000thti
Event Type
earthquake
Status
✓ Reviewed
Significance
259
Stations Used
32
Azimuthal Gap
102.0°
Min Station Distance
20.151°
RMS Residual
0.47 sec
Last Updated
2026-08-11 22:12:03 UTC

Common Questions

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

The magnitude 4.1 earthquake that struck 21 km ESE of Looc, Philippines on July 29, 2026 at 00:23 UTC had a depth of 199.4 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 7 km NW of Cabacao, 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: us6000thti). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, July 29, 2026). M4.1 Earthquake 21 km ESE of Looc, PhilippinesJuly 29, 2026. Retrieved August 11, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000thti/