M4.7 Earthquake 73 km WNW of Basco, Philippines — October 30, 2021
2021-10-30 16:09:37 UTC (2021-10-30) · approx. 12:09 AM UTC+8 local
Felt by 3 people across nearby locations.
On October 30, 2021 at 16:09 UTC, a magnitude 4.7 shallow crustal earthquake struck 73 km WNW of Basco, Philippines, at a depth of 29.2 km and coordinates 20.6533°, 121.3007°.
Physical scale: An earthquake of magnitude 4.7 releases seismic energy equivalent to roughly 169 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.1 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 3 citizen responses 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
121.3007°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.7 earthquake near Basco, Philippines?
The magnitude 4.7 earthquake that struck 73 km WNW of Basco, Philippines on October 30, 2021 at 16:09 UTC had a depth of 29.2 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 20.6533°, 121.3007°, which is 73 km WNW of Basco, Philippines. View all earthquakes in Philippines.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.7 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 4.7 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000fq4g). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, October 30, 2021). M4.7 Earthquake 73 km WNW of Basco, Philippines — October 30, 2021. Retrieved January 14, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000fq4g/