Significant M5.5 AFTERSHOCK hit in the South Pacific Ocean 120km from Nuku‘alofa (Tonga) on Wednesday Evening.

Written by Earthquakelist.org on November 20th, 2024. Last updated November 21st, 2024.

A significant MAG-5.5 aftershock struck in the South Pacific Ocean 120 kilometer from Nuku‘alofa, Tonga just before midnight of Wednesday November 20th, 2024. Shaking may have been felt by a total of 90 thousand people.

Earthquake Summary

This earthquake hit under water in the South Pacific Ocean, 110 kilometers (68 mi) off the coast of Tonga, 120 kilometer west-northwest of Nuku‘alofa in Tongatapu. The center of this earthquake had an intermediate depth of 228 km.

Date and Time:	Nov 20, 2024 11:42PM (Tongatapu Time) - Nov 20, 2024 10:42 Universal Time.
Location:	120 km WNW of Nuku‘alofa, Tongatapu, Tonga. Coordinates 20°43'39"S 176°16'17"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.5 Detected by 38 stations. Maximum Error Range ±0.05 .
Depth:	228 km (141 mi) An intermediate depth.
Max. Intensity:	IV Light On the Modified Mercalli Scale.
Tsunami Risk:	Tsunami very unlikely Earthquakes under MAG-6.5 at depths deeper than 100km are very unlikely to cause tsunami's. Always stay cautious - More info here.

Minimal impact predicted

Based on scientific estimates by the US Geographic Survey (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 90 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 90 thousand have been exposed to shaking at an MMI level of II or higher.

Weak shaking and probably no damage may have been experienced by an estimated 85,700 people. At III, it is the highest MMI level this earthquake has caused.

People in 2 countries have been exposed to shaking. In Tonga , around 90 thousand people, with impact levels up to III (weak shaking, probably no damage).

People	MMI Level	Shaking	Damage
0	I	Not noticable	None
1,710	II	Very weak	None
85,700	III	Weak	Probably none
0	IV	Light	Likely none
0	V	Moderate	Very light
0	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 120 kilometer (75 mi) west-northwest of Nuku‘alofa. The intensity of shaking and damage in Nuku‘alofa is estimated to be around level III on the Modified Mercalli Intensity scale (weak shaking, probably no damage).

Overview of nearby places

Cities and Towns around the epicenter of this earthquake.
Distance	Place	Intensity (MMI)
120 km (75 mi) ESE from epicenter	Nuku‘alofa Tongatapu, Tonga.	III Weak

Earthquake Intensity Map

The maximum intensity (MMI Scale) caused by this earthquake is III. 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 3 people

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 3 people have reported shaking in 2 places in Tonga.We keep updating this article as more ground reports become available. You may report that you felt this earthquake here.

Places with most reports:

Nukuʿalofa, Tongatapu, Tonga: 2 people.
Tofoa-Koloua, Tongatapu, Tonga: 1 person.

This is likely an aftershock

This earthquake was an aftershock. A larger mag. 5.6 earthquake struck 67 km (41 mi) south-east in advance of this 5.5 earthquake around 1 day earlier.

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	M 5.6	Nov 19, 2024 03:41PM (Tongatapu Time)	-
Aftershock This Earthquake	M 5.5	1 day later Nov 20, 2024 11:42PM (Tongatapu Time)	67 km (41 mi) NW 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.

In only six percent of cases, significant earthquakes are followed by a larger main shock, making the current earthquake a foreshock. While the chance of this happening is not so large, it is adviced to maintain cautiousness in the hours and days following a major earthquake.

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

Earthquakes like this happen often in the region

Earthquakes of this strength are very common in the region. In total, 133 earthquakes with a magnitude of 5.5 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 27 days.

Tsunami very unlikely

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.

For a serious tsunami to occur, earthquakes usually need to have a magnitude of at least 6.5 and occur at a shallow depth of maximum 100km. Neither are the case with this earthquake. However always stay cautious and monitor advice from local authorities.

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.	Not this earthquake. This earthquake had a magnitude of 5.5. Earthquakes of this strength are unlikely to trigger a tsunami.	Not this earthquake. This earthquake occurred at a depth of 228 km (141 mi). Earthquakes this deep in the earth are unlikely to trigger a tsunami.

Sources

Last updated 21/11/24 06:08 (). 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.