M4.7 Earthquake 54 km E of Yilan, Taiwan — August 4, 2021
2021-08-04 21:53:24 UTC (2021-08-04) · approx. 5:53 AM UTC+8 local
On August 4, 2021 at 21:53 UTC, a magnitude 4.7 shallow crustal earthquake struck 54 km E of Yilan, Taiwan, at a depth of 12.4 km and coordinates 24.6792°, 122.2861°.
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 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
122.2861°E
Technical Information
Common Questions
How strong was the magnitude 4.7 earthquake near Yilan, Taiwan?
The magnitude 4.7 earthquake that struck 54 km E of Yilan, Taiwan on August 4, 2021 at 21:53 UTC had a depth of 12.4 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 24.6792°, 122.2861°, which is 54 km E of Yilan, Taiwan. View all earthquakes in Taiwan.
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 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 4.7 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000f4jq). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, August 4, 2021). M4.7 Earthquake 54 km E of Yilan, Taiwan — August 4, 2021. Retrieved October 14, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000f4jq/