4.6

M4.6 Earthquake 247 km WNW of Houma, TongaApril 1, 2026

2026-04-01 23:49:37 UTC (2026-04-01) · approx. 11:49 AM UTC-12 local

MagnitudeM4.6(mb)
Time23:49 UTC11:49 AM UTC-12
Depth543.8 kmdeep-focus
Coordinates-20.165°, -177.423°
Felt byNo felt reports
Status✓ Reviewed by USGS

On April 1, 2026 at 23:49 UTC, a magnitude 4.6 deep-focus earthquake struck 247 km WNW of Houma, Tonga, at a depth of 543.8 km and coordinates -20.1651°, -177.4225°. This earthquake was detected by 29 seismic stations with good location accuracy and was assigned a USGS significance rating of 326, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 m — 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 -20.17°, -177.42°

Earthquake Details

Magnitude
4.6 mb
Depth
543.8 km
deep-focus
Location
-20.1651°N
-177.4225°E

Technical Information

Event ID
us6000snzm
Event Type
earthquake
Status
✓ Reviewed
Significance
326
Stations Used
29
Azimuthal Gap
97.0°
Min Station Distance
4.767°
RMS Residual
0.36 sec
Last Updated
2026-04-22 03:32:38 UTC

Common Questions

How strong was the magnitude 4.6 earthquake near Houma, Tonga?

The magnitude 4.6 earthquake that struck 247 km WNW of Houma, Tonga on April 1, 2026 at 23:49 UTC had a depth of 543.8 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -20.1651°, -177.4225°, which is 247 km WNW of Houma, Tonga. View all earthquakes in Tonga.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 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 4.6 event is significantly smaller than that historical record.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.

Authoritative source: USGS event page (event ID: us6000snzm). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, April 1, 2026). M4.6 Earthquake 247 km WNW of Houma, TongaApril 1, 2026. Retrieved May 18, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000snzm/