Strong M6.9 Earthquake struck on Monday Afternoon in the South Pacific Ocean 148km from Nuku‘alofa (Tonga).

Written by Earthquakelist.org on August 25th, 2024. Last updated October 24th, 2024.

Around noon of Monday August 26th, 2024, a strong Magnitude 6.9 earthquake hit in the South Pacific Ocean 148 kilometer from Nuku‘alofa, Tonga. The USGS has indicated there is a potential risk at tsunami's following this earthquake.

Earthquake Summary

This earthquake hit under water in the South Pacific Ocean, 142 kilometers (88 mi) off the coast of Tonga, 148 kilometer north of Nuku‘alofa in Tongatapu. The center of this earthquake had an intermediate depth of 96 km.

Date and Time:	Aug 26, 2024 12:29PM (Tongatapu Time) - Aug 25, 2024 23:29 Universal Time.
Location:	148 km north of Nuku‘alofa, Tongatapu, Tonga. Coordinates 19°48'45"S 175°4'16"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 6.9 Detected by 11 stations. Maximum Error Range ±0.033 .
Depth:	96 km (60 mi) An intermediate depth.
Max. Intensity:	VII Very Strong On the Modified Mercalli Scale.
Tsunami Risk:	Potential tsunami risk The USGS has indicated there is a potential risk at tsunami's following this earthquake. Always stay cautious - More info here.

Potential tsunami risk

DISCLAIMER: We strongly suggest to closely monitor advice from local authorities with regards to tsunami risks. Our analysis is based on automatically collected data from external sources, and these might contain mistakes. In addition, earthquakes can cause landslides that may lead to a tsunami, or be a followed by another, potentially stonger, earthquake.

There is a potential tsunami risk in the aftermath of this earthquake, immediately evacuate to higher grounds away from coastal areas and monitor advice from local authorities. The US Geographic Survey organization has indicated a potential risk for tsunami's following this earthquake.

Tsunami Risk Factors

Factor	Under Sea?	MAG-6.5 or stronger?	Shallow depth?
Explanation	Almost all tsunami's are caused by earthquakes with their epicenter under sea or very near the sea. However stay cautious in coastal areas as earthquakes on land may cause landslides into sea, potentially still causing a local tsunami.	Under MAG 6.5: Very unlikely to cause a tsunami. MAG 6.5 to 7.5: Destructive tsunami's do occur, but are uncommon. Likely to observe small sea level changes. MAG 7.6+: Earthquakes with these magnitudes might produce destructive tsunami's.	Most destructive tsunami's are caused by shallow earthquakes with a depth between 0 and 100km under the surface of the earth. Deeper tsunami's are unlikely to displace to ocean floor.
This Earthquake	This earthquake appears to have struck under the sea.	This earthquake had a magnitude of 6.9. Earthquakes of this strength could trigger a tsunami.	This earthquake occurred at a depth of of 96 km (60 mi). Earthquakes this shallow could trigger a tsunami.

Minimal impact predicted

The US Geographic Survey (USGS) describes the impact of this earthquake as follows:

Damage to Tonga's undersea cable caused communication outages in the Ha`apai Group and Vava`u Group.

Based on scientific estimates by the USGS, the risk of high fatalities for this earthquake is classified at level GREEN (low). They expect an 65% likelyhood of between 0 and 1 fatalities, and a 96% chance that the number of fatalities falls no higher than 10.

The USGS classifies the economic impact of this earthquake at level GREEN (low). They expect an 65% likelyhood of between 0 and 1 million US Dollars in economic damage and impact, and a 96% chance that the economic impact of this earthquake falls no higher than 10 million USD.

Roughly 110 thousand people exposed to shaking

The USGS has published a report estimating the number of people exposed to this earthquake. Acoording to their analysis, roughly 110 thousand have been exposed to shaking at an MMI level of II or higher.

An estimated 5,270 people were exposed to level VI. At this level, strong shaking and probably light damage can be expected. Intensity level V was experienced by the majority of people (around 80 thousand). In their region, moderate shaking and very light damage can be expected. All exposure to shaking was within the borders of Tonga .

People	MMI Level	Shaking	Damage
0	I	Not noticable	None
0	II	Very weak	None
0	III	Weak	Probably none
21,140	IV	Light	Likely none
81,130	V	Moderate	Very light
5,270	VI	Strong	Light
0	VII	Very Strong	Moderate
0	VIII	Severe	Moderate to heavy
0	IX	Violent	Heavy
0	X	Extreme	Very heavy

Nearby towns and cities

This earthquake may have been felt in Tonga . Nuku‘alofa in Tongatapu, Tonga is the nearest significant place from the epicenter. The earthquake occurred 148 kilometer (92 mi) north of Nuku‘alofa. The intensity of shaking and damage in Nuku‘alofa is estimated to be around level V on the Modified Mercalli Intensity scale (moderate shaking, very light damage).

Overview of nearby places

Cities and Towns around the epicenter of this earthquake.
Distance	Place	Intensity (MMI)
148 km (92 mi) S from epicenter	Nuku‘alofa Tongatapu, Tonga.	V Moderate

Earthquake Intensity Map

The maximum intensity (MMI Scale) caused by this earthquake is VI. The map below shows in which areas this earthquake was the most and least impactful. It is based on data from the US Geographic Survey.

I Not felt

II Weak

III Weak

IV Light

V Moderate

VI Strong

VII Very Strong

VIII Severe

IX Violent

X Extreme

Earthquake Intensity Map based on Shakemap Data provided by USGS.

Shaking reported by 21 people in 2 countries

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 21 people have reported shaking in 7 places in 2 countries (Tonga, Niue).We keep updating this article as more ground reports become available. You may report that you felt this earthquake here.

Places with most reports:

Pangai, Haʿapai, Tonga: 6 people.
Nukuʿalofa, Tongatapu, Tonga: 6 people.
Haveloloto, Tongatapu, Tonga: 3 people.
Neiafu, Vavaʿu, Tonga: 2 people.
Avatele, _no region, Niue: 2 people.
Alofi, _no region, Niue: 1 person.
Tamakautoga, _no region, Niue: 1 person.

3 Aftershocks detected

Since this main shock, 3 smaller aftershocks were detected. At a distance of 11 km (7 mi) east-northeast of this earthquake, an aftershock struck 2 mins later. It measured a magnitude of 6

Overview of foreshocks and aftershocks

Detected MAG2.5+ earthquakes within within 100km (62 mi), that occurred in the three days before and after the main shock.
Classification	Magnitude	When	Where
Main Shock This Earthquake	M 6.9	Aug 26, 2024 12:29PM (Tongatapu Time)	-
Aftershock	M 6.0	2 mins later Aug 26, 2024 12:30PM (Tongatapu Time)	11 km (7 mi) ENE from Main Shock.
Aftershock	M 5.3	9 mins later Aug 26, 2024 12:37PM (Tongatapu Time)	18 km (11 mi) WSW from Main Shock.
Aftershock	M 4.5	21 mins later Aug 26, 2024 12:50PM (Tongatapu Time)	21 km (13 mi) WSW from Main Shock.

More earthquakes coming?

Aftershocks are usually at least 1 order of magnitude less strong than main shocks. The more time passes, the smaller the chance and likely strength of any potential aftershocks.

It's always adviced to be cautious of the risk of a larger shock following any significant earthquake, however this risk is fairly small. There is a roughly 94 percent change that no larger main shock will follow in the days following this earthquake.

Read: How to Stay Safe during an Earthquake (cdc.gov).

This is an unusually powerful earthquake

Earthquakes of this strength are not so common in the region, but it's not the first time. This is the strongest earthquake to hit since July 2nd, 2023, when a 6.9 magnitude earthquake hit 215 km (134 mi) further north. An even stronger magnitude 7.1 earthquake struck on November 1st, 2014.

In total, 2 earthquakes with a magnitude of 6.9 or higher have been registered within 300km (186 mi) of this epicenter in the past 10 years. This comes down to an average of once every 5 years.

Sources

Last updated 24/10/24 07:18 (). This article is automatically generated based on available data. We keep checking multiple sources for additional information. This article gets updated as new details on this earthquake become available.