5.1

M5.1 Earthquake 215 km WSW of Haveluloto, Tonga — May 17, 2021

2021-05-17 00:31:12 UTC (2021-05-17) · approx. 12:31 PM UTC-12 local

MagnitudeM5.1(mww)
Time00:31 UTC≈ 12:31 PM UTC-12
Depth237.6 kmintermediate depth
Coordinates-21.617°, -177.231°
Felt byNo felt reports
Status✓ Reviewed by USGS

On May 17, 2021 at 00:31 UTC, a magnitude 5.1 intermediate depth earthquake struck 215 km WSW of Haveluloto, Tonga, at a depth of 237.6 km and coordinates -21.6167°, -177.2305°.

Physical scale: An earthquake of magnitude 5.1 releases seismic energy equivalent to roughly 674 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 2.0 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 -21.62°, -177.23°

Earthquake Details

Magnitude
5.1 mww
Depth
237.6 km
intermediate depth
Location
-21.6167°N
-177.2305°E

Technical Information

Event ID
us7000e3n1
Event Type
earthquake
Status
✓ Reviewed
Significance
400
Azimuthal Gap
41.0°
Min Station Distance
16.264°
RMS Residual
0.58 sec
Last Updated
2025-12-22 19:00:11 UTC

Common Questions

How strong was the magnitude 5.1 earthquake near Haveluloto, Tonga?

The magnitude 5.1 earthquake that struck 215 km WSW of Haveluloto, Tonga on May 17, 2021 at 00:31 UTC had a depth of 237.6 km. For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at -21.6167°, -177.2305°, which is 215 km WSW of Haveluloto, Tonga. View all earthquakes in Tonga.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.1 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 5.1 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us7000e3n1). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, May 17, 2021). M5.1 Earthquake 215 km WSW of Haveluloto, Tonga — May 17, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000e3n1/