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M4.2 Earthquake near Hihifo, Tonga — 12 September 2025

A light earthquake of magnitude 4.2 was recorded near Hihifo, Tonga on , with an epicentre 242 km west-northwest of Hihifo, at a focal depth of 374.6 km. It ranked as the 17th strongest of 17 earthquakes recorded in Tonga in the preceding 30 days.

4.2 Light

Time (UTC): 2025-09-12 04:30:28

Time (your timezone): —

Magnitude: 4.2 (light)

Focal depth: 374.6 km (deep)

Epicentre: -15.4976, -176.0100

Location: 242 km WNW of Hihifo, Tonga

Country: Tonga

USGS link to NOAA tsunami information: Not linked

Review status: Reviewed

Source: USGS event page

How strong was this earthquake?

Light earthquakes are widely felt near the epicentre and can rattle windows, dishes and hanging objects. Damage is uncommon and usually limited to cracked plaster or fallen loose items.

A magnitude 4.2 earthquake radiates roughly 30 tons of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 271, which is below the USGS threshold of more than 600 for its significant-earthquake list. The ranking combines magnitude with available Did You Feel It responses and PAGER alert level; it is not a direct measurement of damage.

What the magnitude scale actually measures →

When it happened locally

That is about 16:46 local solar time at the epicentre, during the afternoon.

This event was deeper than 83% of the 401 earthquakes recorded in Tonga in our catalogue and stronger than 3% of them.

Where was the epicentre?

The epicentre was located at -15.4976, -176.0100 — 242 km west-northwest of Hihifo. The closest other recorded event was a magnitude 4.9 earthquake 30 km east-southeast of here on 15 November 2025.

The nearest other settlements in our records are Mata-Utu (34 km northwest), Alo (206 km southwest) and Neiafu (251 km south-southeast).

Why the 375 km depth matters

At 375 km this was a deep-focus earthquake, occurring well inside the subducting slab rather than in the crust. Deep events are rarely damaging even at large magnitudes, though they can be felt over very long distances.

This catalogue does not ingest eyewitness responses, so it cannot confirm where this earthquake was felt. Based on magnitude alone, an event this size is often felt across the surrounding area. Its deep focus normally weakens surface shaking while spreading perceptible motion over a broad area.

Read more on how focal depth changes what you feel →

What does the tsunami information flag mean?

The USGS record does not carry a link to NOAA tsunami information. That field is not an all-clear and does not state whether a tsunami occurred. In this case, a damaging tsunami would be less likely because at M4.2 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; its 375 km focal depth is too great to deform the sea floor significantly; it occurred inland rather than beneath the sea floor. For an active coastal alert, use tsunami.gov or your local warning authority.

How earthquakes generate tsunamis, and what the alert levels mean →

Aftershocks and local seismic history

No further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event.

73 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.6 event near Mata-Utu on 24 July 2025. This M4.2 event released about 3,981 times less energy than that event.

8 earthquakes have been recorded within 100 km of this epicentre in the past year, 0 of them in the past 30 days.

How long aftershock sequences last, and how large they get →

Where this event sits in the record

This earthquake is part of the September 2025 worldwide record, and of earthquakes in Tonga during September 2025. Browse the full monthly archive to compare periods.

Nearest recorded earthquakes to this epicentre

Other recent earthquakes in Tonga

All recorded earthquakes in Tonga →

Other magnitude 4 earthquakes worldwide

All magnitude 4 earthquakes →

Questions about this earthquake

How strong was the earthquake near Hihifo?

It measured magnitude 4.2 — a light earthquake. A magnitude 4.2 earthquake radiates roughly 30 tons of TNT equivalent in seismic energy.

How deep was the earthquake near Hihifo?

The focus was 375 km below the surface, which counts as deep.

Was the Hihifo earthquake felt at the surface?

At magnitude 4.2 and a focal depth of 375 km, the depth spreads the energy out, so shaking is weaker overhead but reaches further.

When did the earthquake near Hihifo happen?

12 September 2025 at 04:30 UTC.

Was there a tsunami?

No. The USGS record carries no tsunami-information link for this event.

Have there been aftershocks?

No further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event.

How often do earthquakes happen near Hihifo?

73 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.6 event near Mata-Utu on 24 July 2025. This M4.2 event released about 3,981 times less energy than that event.