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M5.5 Earthquake near Houma, Tonga — 28 December 2024

A moderate earthquake of magnitude 5.5 was recorded near Houma, Tonga on , with an epicentre 282 km west-northwest of Houma, at a focal depth of 550.6 km.

5.5 Moderate

Time (UTC): 2024-12-28 19:57:20

Time (your timezone): —

Magnitude: 5.5 (moderate)

Focal depth: 550.6 km (deep)

Epicentre: -20.4629, -177.9080

Location: 282 km WNW of Houma, Tonga

USGS link to NOAA tsunami information: Not linked

Review status: Reviewed

Source: USGS event page

How strong was this earthquake?

Moderate earthquakes can damage poorly built or unreinforced structures near the epicentre, while well-engineered buildings typically escape serious harm. Shaking is often strong enough to wake sleeping residents over a wide area.

A magnitude 5.5 earthquake radiates roughly 2,682 tons of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 465, 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 →

Where was the epicentre?

The epicentre was located at -20.4629, -177.9080 — 282 km west-northwest of Houma. The closest other recorded event was a magnitude 4.7 earthquake 1 km northwest of here on 15 April 2026.

Why the 551 km depth matters

At 551 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 can be felt widely and may cause minor local damage. 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 M5.5 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; its 551 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

1 further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event, the largest of them magnitude 4.1.

239 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.3 event near Fiji region on 01 March 2026. This M5.5 event released about 16 times less energy than that event.

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

Where this event sits in the record

This earthquake is part of the December 2024 worldwide record. Browse the full monthly archive to compare periods.

Nearest recorded earthquakes to this epicentre

Other magnitude 5 earthquakes worldwide

All magnitude 5 earthquakes →

Questions about this earthquake

How strong is a magnitude 5.5 earthquake?

Moderate earthquakes can damage poorly built or unreinforced structures near the epicentre, while well-engineered buildings typically escape serious harm. Shaking is often strong enough to wake sleeping residents over a wide area. A magnitude 5.5 earthquake radiates roughly 2,682 tons of TNT equivalent in seismic energy.

How deep was the earthquake near Houma?

At 551 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.

Was the M5.5 earthquake near Houma felt?

This catalogue does not ingest eyewitness responses, so it cannot confirm where this earthquake was felt. Based on magnitude alone, an event this size can be felt widely and may cause minor local damage. Its deep focus normally weakens surface shaking while spreading perceptible motion over a broad area.

What does the USGS tsunami field mean for this event?

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 M5.5 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; its 551 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.

Have there been aftershocks?

1 further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event, the largest of them magnitude 4.1.

How often do earthquakes happen near Houma?

239 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.3 event near Fiji region on 01 March 2026. This M5.5 event released about 16 times less energy than that event.