On Monday Night a Shallow M6.2 AFTERSHOCK struck in the South Pacific Ocean 160km from Nuku‘alofa (Tonga).

Written by Earthquakelist.org on March 30th, 2025. Last updated April 3rd, 2025.

In the night of Monday March 31st, 2025, a shallow and strong Magnitude 6.2 aftershock hit in the South Pacific Ocean 160 kilometer from Nuku‘alofa, Tonga. Roughly 100 thousand people may have felt this earthquake.

Earthquake Summary

This earthquake hit under water in the South Pacific Ocean, 153 kilometers (95 mi) off the coast of Tonga, 160 kilometer east-northeast of Nuku‘alofa in Tongatapu. The center of this earthquake had a very shallow depth of 17 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Mar 31, 2025 04:04AM (Tongatapu Time) 4 days ago - Mar 30, 2025 15:04 Universal Time.
Location:	160 km ENE of Nuku‘alofa, Tongatapu, Tonga. Coordinates 20°25'47"S 173°51'57"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 6.2 Detected by 25 stations. Maximum Error Range ±0.062 .
Depth:	17 km (11 mi) A very shallow depth.
Max. Intensity:	V Moderate On the Modified Mercalli Scale.
Tsunami Risk:	Low tsunami risk Earthquakes under MAG-6.5 do not usually 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 100 thousand people exposed to shaking

This earthquake may have been felt by around 100 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.

The highest earthquake impact level for this earthquake is IV, which corresponds with light shaking and likely no damage. Roughly 73,190 people are expected to be exposed to this level. 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
30,550	III	Weak	Probably none
73,190	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 . Located 160 kilometer (99 mi) east-northeast of the epicenter of this earthquake, Nuku‘alofa (Tongatapu, Tonga) is the nearest significant population center. 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

Cities and Towns around the epicenter of this earthquake.
Distance	Place	Intensity (MMI)
160 km (99 mi) WSW from epicenter	Nuku‘alofa Tongatapu, Tonga.	IV Light

Earthquake Intensity Map

The maximum intensity (MMI Scale) caused by this earthquake is IV. 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.

This is likely an aftershock

Approximately 3 hrs before this earthquake hit, a larger 7 magnitude earthquake struck 12 km (7 mi) north-northwest of this one. For that reason, we classify the Mag. 6.2 earthquake as an aftershock.

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 7.0	Mar 31, 2025 01:18AM (Tongatapu Time)	-
Aftershock	M 4.8	2 hrs later Mar 31, 2025 03:24AM (Tongatapu Time)	23 km (14 mi) E from Main Shock.
Aftershock	M 4.8	3 hrs later Mar 31, 2025 03:58AM (Tongatapu Time)	42 km (26 mi) NNE from Main Shock.
Aftershock This Earthquake	M 6.2	3 hrs later Mar 31, 2025 04:04AM (Tongatapu Time)	12 km (7 mi) SSE from Main Shock.
Aftershock	M 4.9	3 hrs later Mar 31, 2025 04:26AM (Tongatapu Time)	20 km (13 mi) ENE from Main Shock.
Aftershock	M 5.8	3 hrs later Mar 31, 2025 04:33AM (Tongatapu Time)	20 km (13 mi) E from Main Shock.
Aftershock	M 4.8	4 hrs later Mar 31, 2025 05:10AM (Tongatapu Time)	19 km (12 mi) ESE from Main Shock.
Aftershock	M 4.8	7 hrs later Mar 31, 2025 08:30AM (Tongatapu Time)	28 km (17 mi) E from Main Shock.
Aftershock	M 5.3	10 hrs later Mar 31, 2025 10:51AM (Tongatapu Time)	23 km (14 mi) WNW from Main Shock.
Aftershock	M 4.9	1 day later Apr 1, 2025 02:20AM (Tongatapu Time)	20 km (12 mi) SE from Main Shock.
Aftershock	M 5.0	3 days later Apr 2, 2025 01:59PM (Tongatapu Time)	23 km (14 mi) E from Main Shock.

More earthquakes coming?

Earthquakes can create aftershocks. These are generally at least 1 magnitude lower than any main shock, and as time passes the chance and strength of aftershocks decreases.

The chance that a significant earthquake like this one is followed by an even larger earthquake is not so large. On average, scientists estimate a 94% chance that a major earthquake will not be followed by an even larger one. It is still adviced to be aware of this risk

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

Earthquakes like this are common in the region

Earthquakes of this strength occur quite regularly in the region. In total, 11 earthquakes with a magnitude of 6.2 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 year.

Low 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.

Based on early data it appears this earthquake was not strong enough (lower than MAG-6.5) to be likely to cause destructive tsunami's. However this earthquake appeared to have hit at a shallow depth under sea, so 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 6.2. Earthquakes of this strength are unlikely to trigger a tsunami.	This earthquake occurred at a depth of of 17 km (11 mi). Earthquakes this shallow could trigger a tsunami.

Sources

Last updated 03/04/25 14:28 (21 hours ago). 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.