M4.9 Earthquake 95 km N of Hihifo, Tonga — September 14, 2021
2021-09-14 10:28:16 UTC (2021-09-14) · approx. 10:28 PM UTC-12 local
Felt by 1 person across nearby locations.
On September 14, 2021 at 10:28 UTC, a magnitude 4.9 intermediate depth earthquake struck 95 km N of Hihifo, Tonga, at a depth of 109.6 km and coordinates -15.0938°, -173.9028°.
Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 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
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 1 citizen response to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-173.9028°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.9 earthquake near Hihifo, Tonga?
The magnitude 4.9 earthquake that struck 95 km N of Hihifo, Tonga on September 14, 2021 at 10:28 UTC had a depth of 109.6 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -15.0938°, -173.9028°, which is 95 km N of Hihifo, Tonga. View all earthquakes in Tonga.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 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 4.9 event is significantly smaller than that historical record.
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Location
Authoritative source: USGS event page (event ID: us7000fb09). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, September 14, 2021). M4.9 Earthquake 95 km N of Hihifo, Tonga — September 14, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000fb09/