M4.6 Earthquake 6 km E of Hualien City, Taiwan — September 18, 2025
2025-09-18 21:21:40 UTC (2025-09-18) · approx. 5:21 AM UTC+8 local
On September 18, 2025 at 21:21 UTC, a magnitude 4.6 shallow crustal earthquake struck 6 km E of Hualien City, Taiwan, at a depth of 20.0 km and coordinates 23.9796°, 121.6710°. This earthquake was detected by 47 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 Taiwan, a region characterized by the collision of the Luzon volcanic arc with the Eurasian continental margin, where the Philippine Sea Plate converges at 80 mm per year. View all earthquakes in Taiwan.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
121.6710°E
Technical Information
Common Questions
How strong was the magnitude 4.6 earthquake near Hualien City, Taiwan?
The magnitude 4.6 earthquake that struck 6 km E of Hualien City, Taiwan on September 18, 2025 at 21:21 UTC had a depth of 20.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 23.9796°, 121.6710°, which is 6 km E of Hualien City, Taiwan. View all earthquakes in Taiwan.
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 Taiwan had earthquakes this big before?
The largest recorded earthquake in Taiwan was the M7.6 Chi-Chi earthquake of September 21, 1999. Today's magnitude 4.6 event is significantly smaller than that historical record.
What should I do after an earthquake?
If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.
Authoritative source: USGS event page (event ID: us7000qx4l). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, September 18, 2025). M4.6 Earthquake 6 km E of Hualien City, Taiwan — September 18, 2025. Retrieved May 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000qx4l/