Significant M5.5 Earthquake struck on Tuesday Morning in the Sawu Sea 173km from Dili (Timor-Leste).

Written by Earthquakelist.org on April 21st, 2026.

A significant MAG-5.5 earthquake struck in the Sawu Sea 173 kilometer from Dili, Timor-Leste in the morning of Tuesday April 21st, 2026. Shaking may have been felt by a total of 4.2 million people. Another nearby country is Indonesia.

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Earthquake Summary

This earthquake hit under water in the Sawu Sea, 24 kilometers (15 mi) off the coast of Timor-Leste, 173 kilometer west of Dili in Díli. The center of this earthquake had an intermediate depth of 77 km.

Date and Time:	Apr 21, 2026 11:17 (Makassar Time) - Apr 21, 2026 03:17 Universal Time.
Location:	60 km NW of Kefamenanu, East Nusa Tenggara, Indonesia. Coordinates 9°4'5"S 124°5'11"E.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.5 Detected by 16 stations. Maximum Error Range ±0.078 .
Depth:	77 km (48 mi) An intermediate 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 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 4.2 million people exposed to shaking

This earthquake may have been felt by around 4.2 million 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 1,076,000 people. At IV, it is the highest MMI level this earthquake has caused. The majority of people (roughly 3.1 million) live in an area exposed to level III, where weak shaking and probably no damage is expected.

People in 2 countries have been exposed to shaking. Roughly 3 million people were exposed to shaking in Indonesia , with level IV (light shaking, likely no damage) as the highest recorded. In Timor-Leste , around 1.2 million people.

Nearby towns and cities

2 countries can be found within 300km of the epicenter of this earthquake: Indonesia and Timor-Leste .

Located 60 kilometer (37 mi) northwest of the epicenter of this earthquake, Kefamenanu (East Nusa Tenggara, Indonesia) is the nearest significant population center. Kefamenanu experienced an earthquake intensity (MMI Scale) of roughly IV. That level implies light shaking and likely no damage.

The table below provides an overview of all places in proximity of today's earthquake. Where available, the estimated intensity on the Modified Mercalli Intensity Scale in each place is included. Places where this information is omitted likely experienced little impact.

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

Shaking reported by 2 people in 2 countries

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

Places with most reports:

• Dili, Dili, East Timor: 1 person.
• Kupang, Nusa Tenggara Timur, Indonesia: 1 person.

8 Aftershocks detected

This main shock was followed by 8 smaller aftershocks. At a distance of 10 km (6 mi) south-east of this earthquake, an aftershock struck 2 mins later. It measured a magnitude of 4.4

This main shock was prefaced by 4 smaller foreshocks. Nearby this earthquake a foreshock struck 6 hrs earlier. It measured a magnitude of 2.6

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.

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.

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 October 26th, 2025, when a 6.2 magnitude earthquake hit 26 km (16 mi) further northwest. An even stronger magnitude 7.3 earthquake struck on December 14th, 2021.

In total, 22 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 6 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 21/04/26 09:08 (). This article contains currently available information about the earthquake and is automatically composed. We continue to update this article up to a few days after the earthquake occurred.

1. US Geographic Society (USGS): Earthquake us6000srrc
2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20260421_0000048
3. Geonames.org: World Cities Database
4. Google Maps: Static API
5. Earthquakelist.org: Historic Earthquakes Database

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