M4.8 earthquake 32 km WNW of Nuku‘alofa, Tongatapu, Tonga
A magnitude 4.8 earthquake struck 32 km WNW of Nuku‘alofa, Tongatapu, Tonga at 09:11 local time (20:11 UTC) on 23 Sept 2026, at a depth of 122 km, according to USGS and GFZ.
Reported by 2 agencies · revised from M4.9
Data: USGS, GFZ · updated 2026-09-22 20:46 UTC · reviewed
- Magnitude
- 4.8light
body-wave magnitude (mb)
revised from 4.9 - Depth
- 121.9 km
- Status
- Reviewed
- Origin time
- 2026-09-22 20:11:50 UTC
- Local: 23 Sept 2026, 09:11:50 (Pacific/Tongatapu)
- Epicentre
- 20.984° S, 175.461° W
Circles show this event and others within 32 km from 7 days before to 30 days after. Lines: plate boundaries and GEM active faults. Open on the live map
Nearby places
| Place | Distance | Est. shaking |
|---|---|---|
| Nuku‘alofaTongatapu, Tonga · pop. 22,400 | 32 km | IIWeak |
| 'OhonuaʻEua, Tonga · pop. 1,466 | 65 km | IIWeak |
Shaking is an estimate from the intensity prediction equation of Allen, Wald & Worden (2012), not an observation. Local ground and buildings can change it by a level or more.
Every agency's solution
Agencies locate earthquakes with their own stations and methods, so their numbers differ. We match reports of the same event by time, distance and magnitude and show them side by side. The headline uses USGS, which has been reviewed by an analyst.
How big was it?
Widely felt near the epicentre: rattling windows and objects. Significant damage is unlikely.
It released roughly the energy of 239 t of TNT. Magnitude is logarithmic: each whole step means about 32 times more energy and 10 times larger waves on a seismogram. Depth matters too: at 122 km this was a intermediate-depth earthquake, which spreads shaking over a wider area but less intensely.
M4.8 releases about 32× the energy of M3.8, and its waves are about 10× taller on a seismogram. Energy: 239 t of TNT vs 7.6 t of TNT.
Each square is the energy of one M3.8. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
No later earthquakes have been recorded within 32 km so far. Aftershock rates usually fall off roughly in proportion to 1/time.
Did you feel it?
Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.
Reports on SeismoAtlas
No reports yet.
Event id gfz2026spwu. First recorded here 28 Sept 2026, 17:32:06 UTC. Solutions: GFZ (geofon:gfz2026spwu); USGS (usgs:us6000twyf). Cite as: SeismoAtlas, “M4.8 earthquake 32 km WNW of Nuku‘alofa, Tongatapu, Tonga”, https://seismoatlas.com/earthquake/gfz2026spwu-m4-8-earthquake-32-km-wnw-of-nuku-alofa-tongatapu-tonga, data from USGS, GFZ.
JSON: /api/v1/events/gfz2026spwu. SeismoAtlas is not an official warning service.