Strong M6.6 Earthquake hit in the South Pacific Ocean near Vallenar (Chile) on Tuesday Morning.

Written by Earthquakelist.org on October 31st, 2023. Last updated December 8th, 2023.

In the South Pacific Ocean 80 kilometer from Vallenar, Chile, a strong MAG-6.6 earthquake occurred in the morning of Tuesday October 31st, 2023. The USGS has indicated there is a potential risk at tsunami's following this earthquake. Another country near the epicenter is Argentina.

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Earthquake Summary

This earthquake hit under water in the South Pacific Ocean, right off the coast of Chile (9 mi offshore), 80 kilometer west-southwest of Vallenar in Atacama. The center of this earthquake had a quite shallow depth of 35 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Oct 31, 2023 09:33 (Santiago Time) - Oct 31, 2023 12:33 Universal Time.
Location:	80 km WSW of Vallenar, Atacama, Chile. Coordinates 28°44'42"S 71°33'17"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 6.6 Detected by 21 stations. Maximum Error Range ±0.069 .
Depth:	35 km (22 mi) A quite shallow depth.
Max. Intensity:	VII Very Strong On the Modified Mercalli Scale.
Tsunami Risk:	Potential tsunami risk The USGS has indicated there is a potential risk at tsunami's following this earthquake. Always stay cautious - More info here.

Potential tsunami risk

There is a potential tsunami risk in the aftermath of this earthquake, immediately evacuate to higher grounds away from coastal areas and monitor advice from local authorities. The US Geographic Survey organization has indicated a potential risk for tsunami's following this earthquake.

Tsunami Risk Factors

Minimal impact predicted

The US Geographic Survey (USGS) describes the impact of this earthquake as follows:

One home destroyed by rockfalls at Las Breas; six homes damaged at Vallenar. Some buildings damaged at Freirina and San Felix. Rockslides reported at Copiapo, Coquimbo, Freirina, La Serena and Vallenar.

Based on scientific estimates by the 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 98% likelyhood of between 0 and 1 million US Dollars in economic damage and impact.

Roughly 0.8 million people exposed to shaking

The USGS has published a report estimating the number of people exposed to this earthquake. Acoording to their analysis, roughly 0.8 million have been exposed to shaking at an MMI level of II or higher.

The highest earthquake impact level for this earthquake is VII, which corresponds with very strong shaking and likely moderate damage. Roughly 390 people are expected to be exposed to this level. Intensity level IV was experienced by the majority of people (around 740 thousand). In their region, light shaking and likely no damage can be expected.

People in 2 countries have been exposed to shaking. In Chile , around 0.8 million people, with impact levels up to VII (very strong shaking, likely moderate damage). Shaking was experienced by inhabitants of Argentina too.

Nearby towns and cities

Chile and Argentina are both located within 300km distance of the epicenter of the earthquake.

The closest significant population center near the earthquake is Vallenar in Atacama, Chile. Vallenar is located 80 kilometer (50 mi) west-southwest of the epicenter. The intensity of shaking and damage in Vallenar is estimated to be around level V on the Modified Mercalli Intensity scale (moderate shaking, very light damage).

Multiple major population centers exist within 300km of the earthquake that struck today. Coquimbo is located 136 km to the south and experienced an intensity of IV (light shaking, likely no damage). La Serena is located 132 km to the south-southeast and experienced an intensity of IV (light shaking, likely no damage). San Juan is located 425 km to the south-east (intensity unknown, possibly low).

An overview of nearby towns and cities is available in the overview below. If places don't have intensity data available, it likely means the experienced impact in those places was fairly small.

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 VII.

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 59 people in 2 countries

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 59 people have reported shaking in 22 places in 2 countries (Argentina, Chile).We keep updating this article as more ground reports become available. You may report that you felt this earthquake here.

Places with most reports:

• Santiago, Metropolitana, Chile: 14 people.
• La Serena, Coquimbo, Chile: 6 people.
• Viña del Mar, Valparaíso, Chile: 4 people.
• San Juan, San Juan, Argentina: 4 people.
• Coquimbo, Coquimbo, Chile: 4 people.
• Mendoza, Mendoza, Argentina: 3 people.
• Diego de Almagro, Atacama, Chile: 3 people.
• Córdoba, Córdoba, Argentina: 3 people.
• Lampa, Metropolitana, Chile: 2 people.
• Quilpué, Valparaíso, Chile: 2 people.

10 Aftershocks detected

This main shock was followed by 10 smaller aftershocks. Just 2 days after this main shock, an earthquake measuring MAG-4 was detected 99 km (62 mi) north-northeast of this earthquake.

Overview of foreshocks and aftershocks

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.

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

This is the strongest earthquake in 3 years

Earthquakes of this strength occur quite regularly in the region. This is the strongest earthquake to hit since September 1st, 2020, when a 6.8 magnitude earthquake hit 90 km (56 mi) further north-northeast. An even stronger magnitude 6.9 earthquake struck on November 11th, 2015.

In total, 6 earthquakes with a magnitude of 6.6 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 years.

Sources

Last updated 08/12/23 02:48 (). 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 us7000l7si
2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20231031_0000107
3. Geonames.org: World Cities Database
4. Google Maps: Static API
5. Earthquakelist.org: Historic Earthquakes Database

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