4.3

M4.3 Earthquake 43 km E of Union, PhilippinesDecember 4, 2023

2023-12-04 21:00:25 UTC (2023-12-04) · approx. 5:00 AM UTC+8 local

MagnitudeM4.3(mb)
Time21:00 UTC5:00 AM UTC+8
Depth35.0 kmshallow crustal
Coordinates9.804°, 126.503°
Felt byNo felt reports
Status✓ Reviewed by USGS

On December 4, 2023 at 21:00 UTC, a magnitude 4.3 shallow crustal earthquake struck 43 km E of Union, Philippines, at a depth of 35.0 km and coordinates 9.8038°, 126.5027°.

Physical scale: An earthquake of magnitude 4.3 releases seismic energy equivalent to roughly 43 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 558 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 9.80°, 126.50°

Earthquake Details

Magnitude
4.3 mb
Depth
35.0 km
shallow crustal
Location
9.8038°N
126.5027°E

Technical Information

Event ID
us7000lhii
Event Type
earthquake
Status
✓ Reviewed
Significance
284
Stations Used
24
Azimuthal Gap
143.0°
Min Station Distance
2.866°
RMS Residual
0.55 sec
Last Updated
2024-02-10 23:47:31 UTC

Common Questions

How strong was the magnitude 4.3 earthquake near Union, Philippines?

The magnitude 4.3 earthquake that struck 43 km E of Union, Philippines on December 4, 2023 at 21:00 UTC had a depth of 35.0 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 4.3 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.3 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000lhii). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, December 4, 2023). M4.3 Earthquake 43 km E of Union, PhilippinesDecember 4, 2023. Retrieved February 10, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000lhii/