M4.9 Earthquake 16 km NNW of Biri, Philippines — August 18, 2023
2023-08-18 18:35:15 UTC (2023-08-18) · approx. 2:35 AM UTC+8 local
Felt by 1 person across nearby locations.
On August 18, 2023 at 18:35 UTC, a magnitude 4.9 intermediate depth earthquake struck 16 km NNW of Biri, Philippines, at a depth of 93.1 km and coordinates 12.8171°, 124.3060°. This earthquake was detected by 85 seismic stations with good location accuracy and was assigned a USGS significance rating of 370, 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.
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
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 1 citizen response to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
124.3060°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.9 earthquake near Biri, Philippines?
The magnitude 4.9 earthquake that struck 16 km NNW of Biri, Philippines on August 18, 2023 at 18:35 UTC had a depth of 93.1 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 12.8171°, 124.3060°, which is 16 km NNW of Biri, Philippines. View all earthquakes in Philippines.
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.
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 4.9 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000kpba). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, August 18, 2023). M4.9 Earthquake 16 km NNW of Biri, Philippines — August 18, 2023. Retrieved October 27, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000kpba/