4.7

M4.7 Earthquake 128 km NNW of Neiafu, TongaMay 17, 2025

2025-05-17 20:56:18 UTC (2025-05-17) · approx. 8:56 AM UTC-12 local

MagnitudeM4.7(mb)
Time20:56 UTC8:56 AM UTC-12
Depth86.8 kmintermediate depth
Coordinates-17.553°, -174.379°
Felt byNo felt reports
Status✓ Reviewed by USGS

On May 17, 2025 at 20:56 UTC, a magnitude 4.7 intermediate depth earthquake struck 128 km NNW of Neiafu, Tonga, at a depth of 86.8 km and coordinates -17.5528°, -174.3787°. This earthquake was detected by 51 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 340, placing it among routine seismic activity.

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

Map showing earthquake epicenter at -17.55°, -174.38°

Earthquake Details

Magnitude
4.7 mb
Depth
86.8 km
intermediate depth
Location
-17.5528°N
-174.3787°E

Technical Information

Event ID
us7000pzw8
Event Type
earthquake
Status
✓ Reviewed
Significance
340
Stations Used
51
Azimuthal Gap
61.0°
Min Station Distance
4.402°
RMS Residual
1.22 sec
Last Updated
2025-07-25 17:06:18 UTC

Common Questions

How strong was the magnitude 4.7 earthquake near Neiafu, Tonga?

The magnitude 4.7 earthquake that struck 128 km NNW of Neiafu, Tonga on May 17, 2025 at 20:56 UTC had a depth of 86.8 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -17.5528°, -174.3787°, which is 128 km NNW of Neiafu, 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.

Authoritative source: USGS event page (event ID: us7000pzw8). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, May 17, 2025). M4.7 Earthquake 128 km NNW of Neiafu, TongaMay 17, 2025. Retrieved July 25, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000pzw8/