M4.7 Earthquake 139 km ESE of Hihifo, Tonga — June 21, 2021
2021-06-21 17:32:18 UTC (2021-06-21) · approx. 5:32 AM UTC-12 local
On June 21, 2021 at 17:32 UTC, a magnitude 4.7 shallow crustal earthquake struck 139 km ESE of Hihifo, Tonga, at a depth of 10.0 km and coordinates -16.5676°, -172.6514°.
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 Tonga, a region characterized by the Tonga-Kermadec subduction zone, where the Pacific Plate descends at up to 240 mm per year — the fastest plate convergence on Earth. The nearest mapped fault system is the Tonga Trench. View all earthquakes in Tonga.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
-172.6514°E
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Common Questions
How strong was the magnitude 4.7 earthquake near Hihifo, Tonga?
The magnitude 4.7 earthquake that struck 139 km ESE of Hihifo, Tonga on June 21, 2021 at 17:32 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 -16.5676°, -172.6514°, which is 139 km ESE of Hihifo, Tonga. View all earthquakes in Tonga.
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 Tonga had earthquakes this big before?
The largest recorded earthquake in Tonga was the M8.1 Tonga Trench earthquake of June 26, 1917. Today's magnitude 4.7 event is significantly smaller than that historical record.
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Location
Authoritative source: USGS event page (event ID: us6000epq6). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, June 21, 2021). M4.7 Earthquake 139 km ESE of Hihifo, Tonga — June 21, 2021. Retrieved August 27, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000epq6/