Tonga earthquakes

M6.9 earthquake 132 km NW of Neiafu, Tonga

A magnitude 6.9 earthquake struck 132 km NW of Neiafu, Tonga on Sun, Jul 2, 2023, 11:27 PM GMT+13 (10:27 UTC), 229 km (142 mi) below the surface.

Nuku‘alofa forecastMore in Tonga

Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude
6.9 (Mww, W-phase moment), strong
Magnitude from
USGS National Earthquake Information Center
Local time
UTC
2023-07-02 10:27:43 UTC
Depth
229.0 km (142.3 mi), intermediate-depth
Epicenter
17.881° S, 174.948° W
Region
Tonga
Felt reports
21
Strongest shaking
IV, light shaking
PAGER alert
Green
Tsunami flag
Yes: a large quake in an oceanic region
Status
Reviewed by a seismologist

Magnitude estimates

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.ScaleComputed byNotes
6.9Mww, W-phase momentUSGS National Earthquake Information CenterPreferred · Reviewed · ±0.041 · 58 stations
6.7MiNOAA National Tsunami Warning CenterReviewed · 5 stations
6.7MiNOAA Pacific Tsunami Warning CenterReviewed · 8 stations
6.1MiNOAA National Tsunami Warning CenterFirst automatic solution · Reviewed · 5 stations
6.9Mwc, centroid momentUSGS National Earthquake Information CenterMoment tensor · Reviewed
6.8Mwb, body-wave momentUSGS National Earthquake Information CenterMoment tensor · Reviewed
6.9Mww, W-phase momentUSGS, automatic first solutionFirst automatic solution · Confirmed

Tsunami

The USGS flags a quake this large in an oceanic region. The flag does not mean a tsunami happened; the tsunami warning centers decide that, and their messages are below when they issued any.

Current tsunami warnings: tsunami.gov. Warnings in force in the US also appear on our alerts pages.

Shaking

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

Strongest estimated
IV, light shaking
Peak ground acceleration
3.1% of gravity
Peak ground velocity
2.2 cm/s
Map
Automatic
USGS ShakeMap: estimated shaking intensity around the epicenter
Estimated shaking intensity. Map: USGS ShakeMap.

Did you feel it?

21 people reported to the USGS what they felt; the strongest reported shaking was IV, light shaking.

Did You Feel It? map: shaking reported by the public
Shaking reported by the public, by area. Map: USGS Did You Feel It?

Estimated impact

The USGS PAGER system estimates deaths and economic losses from the shaking and the population and buildings exposed to it.

Alert level
Green: little or no damage or loss of life expected
Deaths: estimated chance of each range
RangeChance
Under 165%
1 to 1030%
10 to 1004%
100 to 1,000Under 1%
1,000 to 10,000Under 1%
10,000 to 100,000Under 1%
100,000 to 10,000,000Under 1%
Economic losses: estimated chance of each range
Range, million USDChance
Under 165%
1 to 1030%
10 to 1004%
100 to 1,000Under 1%
1,000 to 10,000Under 1%
10,000 to 100,000Under 1%
100,000 to 10,000,000Under 1%

Fault motion and ground failure

How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.

Faulting
Oblique normal
Moment magnitude
6.9 Mww
Nodal plane 1
Strike 266°, dip 29°, rake -32°
Nodal plane 2
Strike 24°, dip 75°, rake -115°
Landslide alert
Green
Liquefaction alert
Green

How well it is located

Reviewed by a seismologist.

Location uncertainty
About 5.0 km horizontally, 1.9 km in depth
Magnitude uncertainty
±0.04
Depth from
From modeling of broad-band P waveforms
Station coverage gap
21°
Stations used
108

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Nearby

Within 100 km, magnitude 3.9 and up: 10 in the 60 days after this one and 4 in the 30 days before it.

After

Before

Earthquakes todayTonga earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000kpls (also filed as at00rx5zq9, pt23183000, usauto6000kpls). Read Sat, Oct 3, 2026, 6:23 AM UTC.