Shallow M5.7 AFTERSHOCK hit near Ruteng in Indonesia on Thursday Morning.

Written by Earthquakelist.org on August 20th, 2026.

Under land 32 kilometer from Ruteng in Indonesia, a shallow and significant Magnitude 5.7 aftershock occurred in the morning of Thursday August 20th, 2026. Shaking may have been felt by a total of 2.9 million people.

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Earthquake Summary

The earthquake struck on land in Indonesia, 32 kilometer (20 mi) north-east of Ruteng in East Nusa Tenggara. 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:	Aug 20, 2026 10:46 (Makassar Time) - Aug 20, 2026 02:46 Universal Time.
Location:	32 km NE of Ruteng, East Nusa Tenggara, Indonesia. Coordinates 8°21'30"S 120°36'37"E.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.7 Detected by 11 stations. Maximum Error Range ±0.093 .
Depth:	10 km (6 mi) A very shallow depth.
Max. Intensity:	VII Very Strong On the Modified Mercalli Scale.
Tsunami Risk:	Tsunami very unlikely While this was a shallow earthquake in a coastal area, it appears to have occurred under land (7 km from the sea) with a magnitude that is usually not strong enough 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 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 2.9 million people exposed to shaking

This earthquake may have been felt by around 2.9 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.

The highest earthquake impact level for this earthquake is VII, which corresponds with very strong shaking and likely moderate damage. Roughly 750 people are expected to be exposed to this level. Intensity level III was experienced by the majority of people (around 1.7 million). In their region, weak shaking and probably no damage can be expected. All exposure to shaking was within the borders of Indonesia .

People	MMI Level	Shaking	Damage
0	I	Not noticable	None
0	II	Very weak	None
1,657,000	III	Weak	Probably none
1,001,000	IV	Light	Likely none
172,100	V	Moderate	Very light
45,610	VI	Strong	Light
750	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 Indonesia . Ruteng in East Nusa Tenggara, Indonesia is the nearest significant place from the epicenter. The earthquake occurred 32 kilometer (20 mi) north-east of Ruteng. The intensity of shaking and damage in Ruteng is estimated to be around level V on the Modified Mercalli Intensity scale (moderate shaking, very light damage).

A complete list of nearby places is included below. Estimated intensity data (MMI) sourced from a shake-map published by the US Geographic Survey is shown where available (cities without data probably experienced little impact).

Overview of nearby places

Earthquake Intensity Map

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

Shaking reported by 1 person

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 1 person has reported shaking in one place in 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:

• Ruteng, Nusa Tenggara Timur, Indonesia: 1 person.

This is likely an aftershock

This earthquake is likely an aftershock of the MAG-5.8 earthquake that struck 4 hrs earlier. That main earthquake hit 10 km (6 mi) southwest of the epicenter of this MAG-5.7 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.

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. In total, 17 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 7 months.

Tsunami very unlikely

While MAG-6.5+ earthquakes may cause tsunami's, it appears that the epicenter of this earthquake hit under land. In addition, the reported depth is deeper than 100km, making the risk of a tsunami even less likely. However always stay cautious and monitor advice from local authorities.

Tsunami Risk Factors

Sources

Last updated 20/08/26 09:38 (). 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 us6000tm1j
2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20260820_0000097
3. Geonames.org: World Cities Database
4. Google Maps: Static API
5. Earthquakelist.org: Historic Earthquakes Database

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