Significant M5.4 Earthquake hit near Vallenar in Chile on Thursday Evening.

Written by Earthquakelist.org on October 26th, 2023. Last updated December 8th, 2023.

Under land 51 kilometer from Vallenar in Chile, a significant M5.4 earthquake occurred in the evening of Thursday October 26th, 2023. Shaking may have been felt by a total of 0.8 million people. Another nearby country is Argentina.

Earthquake Summary

The earthquake struck on land in Chile, 51 kilometer (32 mi) east-southeast of Vallenar in Atacama. The center of this earthquake had an intermediate depth of 101 km.

Date and Time:	Oct 26, 2023 18:49 (Santiago Time) - Oct 26, 2023 21:49 Universal Time.
Location:	51 km ESE of Vallenar, Atacama, Chile. Coordinates 28°42'2"S 70°15'35"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.4 Detected by 57 stations. Maximum Error Range ±0.041 .
Depth:	101 km (63 mi) An intermediate depth.
Max. Intensity:	V Moderate On the Modified Mercalli Scale.
Tsunami Risk:	Tsunami very unlikely Tsunami's are usually caused by MAG-6.5+ earthquakes, less than 100km shallow, and with an epicenter under sea. Neither of this seems to be the case. 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 0.8 million people exposed to shaking

An estimated 0.8 million have been exposed to shaking (An MMI or Modified Mercalli Intensity level II or higher) as a result of this earthquake according scientific estimates published by the USGS.

The highest earthquake impact level for this earthquake is IV, which corresponds with light shaking and likely no damage. Roughly 74,600 people are expected to be exposed to this level. Intensity level III was experienced by the majority of people (around 0.8 million). In their region, weak shaking and probably 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 IV (light shaking, likely no damage). In Argentina, shaking was experienced too.

People	MMI Level	Shaking	Damage
0	I	Not noticable	None
290	II	Very weak	None
774,800	III	Weak	Probably none
74,600	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 struck within proximity of multiple countries. Chile and Argentina are both within 300km distance of its epicenter.

Vallenar in Atacama, Chile is the nearest significant place from the epicenter. The earthquake occurred 51 kilometer (32 mi) east-southeast of Vallenar. The intensity of shaking and damage in Vallenar is estimated to be around level IV on the Modified Mercalli Intensity scale (light shaking, likely no damage).

Major cities near this earthquake: La Serena is located 165 km to the southwest and experienced an intensity of III (weak shaking, probably no damage). Coquimbo is located 174 km to the southwest and experienced an intensity of III (weak shaking, probably no damage). Copiapó is located 148 km to the north and experienced an intensity of III (weak shaking, probably 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

Cities and Towns around the epicenter of this earthquake.
Distance	Place	Intensity (MMI)
51 km (32 mi) WNW from epicenter	Vallenar Atacama, Chile.	IV Light
148 km (92 mi) N from epicenter	Copiapó Atacama, Chile.	III Weak
165 km (103 mi) SW from epicenter	La Serena Coquimbo Region, Chile.	III Weak
174 km (108 mi) SW from epicenter	Coquimbo Coquimbo Region, Chile.	III Weak
225 km (140 mi) SE from epicenter	San José de Jáchal San Juan, Argentina.	III Weak
230 km (143 mi) SSW from epicenter	Ovalle Coquimbo Region, Chile.
258 km (160 mi) N from epicenter	Diego de Almagro Atacama, Chile.
274 km (170 mi) E from epicenter	Chilecito La Rioja, Argentina.

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.

Aftershocks detected

Since this main shock, 1 smaller aftershock was detected. At a distance of 4 km (2.7 mi) west of this earthquake, an aftershock struck 37 mins later. It measured a magnitude of 4.3

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 This Earthquake	M 5.4	Oct 26, 2023 18:49 (Santiago Time)	-
Aftershock	M 4.3	37 mins later Oct 26, 2023 19:26 (Santiago Time)	4 km (2.7 mi) W from Main Shock.

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. This is the strongest earthquake to hit since September 15th, 2023, when a 5.7 magnitude earthquake hit 201 km (125 mi) further northwest. An even stronger magnitude 6.9 earthquake struck on November 11th, 2015.

In total, 83 earthquakes with a magnitude of 5.4 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 month.

Tsunami very unlikely

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.

It is very unlikely that this eartquake will cause any tsunami's. The reported magnitude is lower than the MAG-6.5 strength required to cause any earthquakes. In addition, this earthquake was not very shallow and appears to have occurred under land. However always 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	Not this earthquake. This earthquake appears to have struck on land far from any coast.	Not this earthquake. This earthquake had a magnitude of 5.4. Earthquakes of this strength are unlikely to trigger a tsunami.	Not this earthquake. This earthquake occurred at a depth of 101 km (63 mi). Earthquakes this deep in the earth are unlikely to trigger a tsunami.

Sources

Last updated 08/12/23 03:18 (). As more information on this earthquake becomes available this article will be updated. This article is automatically composed based on data originating from multiple sources.