5.2

M5.2 Earthquake 101 km NNW of Nuku‘alofa, Tonga — May 31, 2021

2021-05-31 00:48:42 UTC (2021-05-31) · approx. 12:48 PM UTC-12 local

MagnitudeM5.2(mww)
Time00:48 UTC≈ 12:48 PM UTC-12
Depth137.4 kmintermediate depth
Coordinates-20.277°, -175.533°
Felt byNo felt reports
Status✓ Reviewed by USGS

On May 31, 2021 at 00:48 UTC, a magnitude 5.2 intermediate depth earthquake struck 101 km NNW of Nuku‘alofa, Tonga, at a depth of 137.4 km and coordinates -20.2770°, -175.5330°.

Physical scale: An earthquake of magnitude 5.2 releases seismic energy equivalent to roughly 951 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 2.3 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

Map showing earthquake epicenter at -20.28°, -175.53°

Earthquake Details

Magnitude
5.2 mww
Depth
137.4 km
intermediate depth
Location
-20.2770°N
-175.5330°E

Technical Information

Event ID
us6000eg3i
Event Type
earthquake
Status
✓ Reviewed
Significance
416
Azimuthal Gap
41.0°
Min Station Distance
6.430°
RMS Residual
0.79 sec
Last Updated
2025-12-22 19:06:57 UTC

Common Questions

How strong was the magnitude 5.2 earthquake near Nuku‘alofa, Tonga?

The magnitude 5.2 earthquake that struck 101 km NNW of Nuku‘alofa, Tonga on May 31, 2021 at 00:48 UTC had a depth of 137.4 km. For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at -20.2770°, -175.5330°, which is 101 km NNW of Nuku‘alofa, Tonga. View all earthquakes in Tonga.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.2 earthquakes can continue for days to weeks 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 5.2 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000eg3i). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, May 31, 2021). M5.2 Earthquake 101 km NNW of Nuku‘alofa, Tonga — May 31, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000eg3i/