M4.7 Earthquake 21 km SSE of Hualien City, Taiwan — July 29, 2021
2021-07-29 22:55:16 UTC (2021-07-29) · approx. 6:55 AM UTC+8 local
On July 29, 2021 at 22:55 UTC, a magnitude 4.7 shallow crustal earthquake struck 21 km SSE of Hualien City, Taiwan, at a depth of 4.8 km and coordinates 23.7882°, 121.6497°.
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
121.6497°E
Technical Information
Common Questions
How strong was the magnitude 4.7 earthquake near Hualien City, Taiwan?
The magnitude 4.7 earthquake that struck 21 km SSE of Hualien City, Taiwan on July 29, 2021 at 22:55 UTC had a depth of 4.8 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 23.7882°, 121.6497°, which is 21 km SSE of Hualien City, Taiwan. View all earthquakes in Taiwan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.7 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: us6000f0f9). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, July 29, 2021). M4.7 Earthquake 21 km SSE of Hualien City, Taiwan — July 29, 2021. Retrieved October 3, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000f0f9/