Written by on . Last updated March 3rd, 2024.

In the South Pacific Ocean 124 kilometer from Nuku‘alofa, Tonga, a significant MAG-5.8 earthquake occurred in the late afternoon of Thursday January 18th, 2024. Roughly 90 thousand people may have felt this earthquake.

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Earthquake Summary

This earthquake hit under water in the South Pacific Ocean, 117 kilometers (72 mi) off the coast of Tonga, 124 kilometer west-southwest of Nuku‘alofa in Tongatapu. The center of this earthquake had an intermediate depth of 155 km.

Date and Time: Jan 18, 2024 05:50PM (Tongatapu Time)
- Jan 18, 2024 04:50 Universal Time.
Location: 124 km WSW of Nuku‘alofa, Tongatapu, Tonga.
Coordinates 21°37'57"S 176°16'45"W.
Map: Map of area around epicenter.
Map of area around epicenter. Click to open in Google Maps.
Magnitude: MAG 5.8
Detected by 14 stations. Maximum Error Range ±0.083 .
Depth: 155 km (96 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

This earthquake may have been felt by around 90 thousand people. That is the expected population size of the area exposed to a level of shaking of II or higher on the Modified Mercalli scale according to the USGS.

Light shaking and likely no damage may have been experienced by an estimated 86,100 people. At IV, it is the highest MMI level this earthquake has caused.

People in 2 countries have been exposed to shaking. Roughly 90 thousand people were exposed to shaking in Tonga , with level IV (light shaking, likely no damage) as the highest recorded.

People MMI Level Shaking Damage
0
I
Not noticable None
0
II
Very weak None
3,760
III
Weak Probably none
86,100
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 124 kilometer (77 mi) west-southwest of the epicenter. The intensity of shaking and damage in Nuku‘alofa is estimated to be around level IV on the Modified Mercalli Intensity scale (light shaking, likely no damage).

Overview of nearby places

Distance Place Intensity (MMI)
124 km (77 mi)
ENE from epicenter
Nuku‘alofa

Tongatapu, Tonga.
IV
Light
Cities and Towns around the epicenter of this earthquake.

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 IV.

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.
  • Ohonua, Eua, Tonga: 1 person.

Aftershocks detected

This main shock was prefaced by 1 smaller foreshock. Roughly 2 days before this earthquake, a foreshock measuring MAG-4.5 was detected nearby this earthquake.

Overview of foreshocks and aftershocks

Classification Magnitude When Where
Foreshock M 4.5 2 days earlier
Jan 17, 2024 03:55AM (Tongatapu Time)
100 km (62 mi)
WSW from Main Shock.
Main Shock
This Earthquake
M 5.8 Jan 18, 2024 05:50PM
(Tongatapu Time)
-
Detected MAG2.5+ earthquakes within within 100km (62 mi), that occurred in the three days before and after the main shock.

More earthquakes coming?

The risk of aftershocks decreases rapidly over time. Usually, aftershocks are at least one order of magnitude lower than a main shock.

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. This is the strongest earthquake to hit since June 25th, 2023, when a 6.2 magnitude earthquake hit 282 km (175 mi) further south-southeast. An even stronger magnitude 7.2 earthquake struck on June 15th, 2023.

In total, 61 earthquakes with a magnitude of 5.8 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 2 months.

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 5.8. Earthquakes of this strength are unlikely to trigger a tsunami.
Not this earthquake.
This earthquake occurred at a depth of 155 km (96 mi). Earthquakes this deep in the earth are unlikely to trigger a tsunami.

Sources

Last updated 03/03/24 04:28 (). As more information on this earthquake becomes available this article will be updated. This article is automatically composed based on data originating from multiple sources.

  1. US Geographic Society (USGS): Earthquake us6000m4c9
  2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20240118_0000050
  3. Geonames.org: World Cities Database
  4. Google Maps: Static API
  5. Earthquakelist.org: Historic Earthquakes Database

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