M4.6 Earthquake 57 km NW of Basco, Philippines — March 13, 2023
2023-03-13 21:53:46 UTC (2023-03-13) · approx. 5:53 AM UTC+8 local
On March 13, 2023 at 21:53 UTC, a magnitude 4.6 shallow crustal earthquake struck 57 km NW of Basco, Philippines, at a depth of 66.2 km and coordinates 20.8660°, 121.6354°. This earthquake was detected by 69 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 326, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 m — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Philippines, a region characterized by the Manila Trench and Philippine Trench subduction systems, where the Philippine Sea Plate overrides the Eurasian Plate. The nearest mapped fault system is the Philippine Fault. View all earthquakes in Philippines.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
121.6354°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.6 earthquake near Basco, Philippines?
The magnitude 4.6 earthquake that struck 57 km NW of Basco, Philippines on March 13, 2023 at 21:53 UTC had a depth of 66.2 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 20.8660°, 121.6354°, which is 57 km NW of Basco, Philippines. View all earthquakes in Philippines.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 earthquakes can continue for several days and gradually diminish over time.
Has Philippines had earthquakes this big before?
The largest recorded earthquake in Philippines was the M8.0 Mindanao earthquake of August 17, 1976. Today's magnitude 4.6 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000jjn9). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, March 13, 2023). M4.6 Earthquake 57 km NW of Basco, Philippines — March 13, 2023. Retrieved May 20, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000jjn9/