Significant M5.4 Earthquake hit in the South Pacific Ocean 283km from Nuku‘alofa (Tonga) on Thursday Morning.

Written by Earthquakelist.org on April 17th, 2024. Last updated April 30th, 2024.

A significant MAG-5.4 earthquake struck in the South Pacific Ocean 283 kilometer from Nuku‘alofa, Tonga in the morning of Thursday April 18th, 2024. Roughly 1 thousand people may have felt this earthquake.

Earthquake Summary

This earthquake hit under water in the South Pacific Ocean, 286 kilometers (178 mi) off the coast of Tonga, 283 kilometer west of Nuku‘alofa in Tongatapu. The center of this earthquake had a deep depth of 390 km.

Date and Time:	Apr 18, 2024 10:31AM (Tongatapu Time) - Apr 17, 2024 21:31 Universal Time.
Location:	283 km west of Nuku‘alofa, Tongatapu, Tonga. Coordinates 21°16'18"S 177°55'31"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.4 Detected by 9 stations. Maximum Error Range ±0.103 .
Depth:	390 km (242 mi) A deep depth.
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 1 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 1 thousand have been exposed to shaking at an MMI level of II or higher.

Very weak shaking and no damage may have been experienced by an estimated 1,070 people. At II, it is the highest MMI level this earthquake has caused. All exposure to shaking was within the borders of Fiji .

People	MMI Level	Shaking	Damage
0	I	Not noticable	None
1,070	II	Very weak	None
0	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 . The closest significant population center near the earthquake is Nuku‘alofa in Tongatapu, Tonga. Nuku‘alofa is located 283 kilometer (176 mi) west of the epicenter.

Overview of nearby places

Cities and Towns around the epicenter of this earthquake.
Distance	Place
283 km (176 mi) E from epicenter	Nuku‘alofa Tongatapu, Tonga.

Earthquake Intensity Map

The intensity in shaking and damage by this earthquake is illustrated through the map below. The highest intensity measured for this earthquake is 0.

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.

Aftershocks detected

After this earthquake struck, 1 smaller aftershock occurred. A 4.3 magnitude earthquake hit 3 days later 79 km (49 mi) west-northwest of this earthquake.

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 5.4	Apr 18, 2024 10:31AM (Tongatapu Time)	-
Aftershock	M 4.3	3 days later Apr 21, 2024 03:00AM (Tongatapu Time)	79 km (49 mi) WNW 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).

Earthquakes like this happen often in the region

Earthquakes of this strength are very common in the region. This is the strongest earthquake to hit since March 31st, 2024, when a 5.5 magnitude earthquake hit 255 km (158 mi) further north-east. An even stronger magnitude 7.2 earthquake struck on June 15th, 2023.

In total, 115 earthquakes with a magnitude of 5.4 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 month.

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 5.4. Earthquakes of this strength are unlikely to trigger a tsunami.	Not this earthquake. This earthquake occurred at a depth of 390 km (242 mi). Earthquakes this deep in the earth are unlikely to trigger a tsunami.

Sources

Last updated 30/04/24 22:08 (). 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.