M4.2 Earthquake 33 km E of Xunchang, China — January 3, 2021
2021-01-03 21:33:23 UTC (2021-01-03) · approx. 4:33 AM UTC+7 local
On January 3, 2021 at 21:33 UTC, a magnitude 4.2 shallow crustal earthquake struck 33 km E of Xunchang, China, at a depth of 10.0 km and coordinates 28.4594°, 105.0555°.
Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — 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 5.0 mainshock that occurred 8 days ago 15 km NNW of Xunchang, China. Since the mainshock, the USGS has recorded 1 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
105.0555°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.2 earthquake near Xunchang, China?
The magnitude 4.2 earthquake that struck 33 km E of Xunchang, China on January 3, 2021 at 21:33 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.2 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.0 one earlier?
No. This magnitude 4.2 earthquake is an aftershock of the larger magnitude 5.0 mainshock that occurred earlier 15 km NNW of Xunchang, China. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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Understanding This Data
Magnitude 4.2 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000d817). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, January 3, 2021). M4.2 Earthquake 33 km E of Xunchang, China — January 3, 2021. Retrieved March 13, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000d817/