On Monday Evening a Shallow M5.7 AFTERSHOCK struck in the South Pacific Ocean 226km from Apia (Samoa).

Written by Earthquakelist.org on March 23rd, 2026. Last updated April 18th, 2026.

In the evening of Monday March 23rd, 2026, a shallow and significant MAG-5.7 aftershock hit in the South Pacific Ocean 226 kilometer from Apia, Samoa. Around 180 thousand people have been exposed to shaking. American Samoa is also near its epicenter.

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Earthquake Summary

This earthquake hit under water in the South Pacific Ocean, 198 kilometers (123 mi) off the coast of Samoa, 226 kilometer southwest of Apia in Tuamasaga. The center of this earthquake had a very shallow depth of 10 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Mar 23, 2026 19:02 (Apia Time) - Mar 23, 2026 06:02 Universal Time.
Location:	226 km SW of Apia, Tuamasaga, Samoa. Coordinates 15°32'45"S 172°53'48"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.7 Detected by 35 stations. Maximum Error Range ±0.052 .
Depth:	10 km (6 mi) A very shallow depth.
Max. Intensity:	IV Light 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 90% likelyhood of between 0 and 1 fatalities.

The USGS classifies the economic impact of this earthquake at level GREEN (low). They expect an 90% likelyhood of between 0 and 1 million US Dollars in economic damage and impact.

Roughly 180 thousand people exposed to shaking

This earthquake may have been felt by around 180 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.

Weak shaking and probably no damage may have been experienced by an estimated 62,080 people. At III, it is the highest MMI level this earthquake has caused. The majority of people (roughly 120 thousand) live in an area exposed to level II, where very weak shaking and no damage is expected.

People in 2 countries have been exposed to shaking. In Samoa , around 180 thousand people, with impact levels up to III (weak shaking, probably no damage).

Nearby towns and cities

Samoa and American Samoa are both located within 300km distance of the epicenter of the earthquake.

Located 226 kilometer (140 mi) southwest of the epicenter of this earthquake, Apia (Tuamasaga, Samoa) is the nearest significant population center. The intensity of shaking and damage in Apia is estimated to be around level III on the Modified Mercalli Intensity scale (weak shaking, probably no damage).

Overview of nearby places

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

This is likely an aftershock

Approximately 15 hrs before this earthquake hit, a larger 6.3 magnitude earthquake struck 35 km (22 mi) north-east of this one. For that reason, we classify the Mag. 5.7 earthquake as an aftershock.

Overview of foreshocks and aftershocks

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.

Earthquakes like this happen often in the region

Earthquakes of this strength are very common in the region. In total, 35 earthquakes with a magnitude of 5.7 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 3 months.

Low tsunami risk

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

Sources

Last updated 18/04/26 00:38 (). 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.

1. US Geographic Society (USGS): Earthquake us6000sisb
2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20260323_0000100
3. Geonames.org: World Cities Database
4. Google Maps: Static API
5. Earthquakelist.org: Historic Earthquakes Database

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