M4.7 Earthquake 14 km ESE of Xunchang, China — May 21, 2023
2023-05-21 19:56:44 UTC (2023-05-21) · approx. 2:56 AM UTC+7 local
Aftershock of the M5.1 mainshock.
On May 21, 2023 at 19:56 UTC, a magnitude 4.7 shallow crustal earthquake struck 14 km ESE of Xunchang, China, at a depth of 10.0 km and coordinates 28.4130°, 104.8535°. This earthquake was detected by 82 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 340, placing it among routine seismic activity.
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.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.1 mainshock that occurred 23 days ago 6 km NNE of Xunchang, China. Since the mainshock, the USGS has recorded 9 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
104.8535°E
Technical Information
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Common Questions
How strong was the magnitude 4.7 earthquake near Xunchang, China?
The magnitude 4.7 earthquake that struck 14 km ESE of Xunchang, China on May 21, 2023 at 19:56 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 28.4130°, 104.8535°, which is 14 km ESE of Xunchang, China.
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.
Is this the same earthquake as the M5.1 one earlier?
No. This magnitude 4.7 earthquake is an aftershock of the larger magnitude 5.1 mainshock that occurred earlier 6 km NNE of Xunchang, China. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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Authoritative source: USGS event page (event ID: us6000kdqt). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, May 21, 2023). M4.7 Earthquake 14 km ESE of Xunchang, China — May 21, 2023. Retrieved July 29, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000kdqt/