On Sunday Evening a Significant M5.7 Earthquake struck near San Juan in Argentina.

Written by Earthquakelist.org on October 20th, 2024. Last updated December 19th, 2024.

In the evening of Sunday October 20th, 2024, a significant M5.7 earthquake hit under land 74 kilometer from San Juan in Argentina. Shaking may have been felt by a total of 1.3 million people. Another country near the epicenter is Chile.

Earthquake Summary

The earthquake struck on land in Argentina, 74 kilometer (46 mi) north-northwest of San Juan. The center of this earthquake had an intermediate depth of 107 km.

Date and Time:	Oct 20, 2024 19:59 (San Juan Time) - Oct 20, 2024 22:59 Universal Time.
Location:	74 km NNW of San Juan, Argentina. Coordinates 30°53'29"S 68°43'46"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.7 Detected by 95 stations. Maximum Error Range ±0.032 .
Depth:	107 km (67 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 1.3 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 1.3 million have been exposed to shaking at an MMI level of II or higher.

The highest earthquake impact level for this earthquake is IV, which corresponds with light shaking and likely no damage. Roughly 747,900 people are expected to be exposed to this level.

People in 2 countries have been exposed to shaking. Roughly 1.2 million people were exposed to shaking in Argentina , with level IV (light shaking, likely no damage) as the highest recorded. In Chile , around 70 thousand people.

People	MMI Level	Shaking	Damage
0	I	Not noticable	None
33,260	II	Very weak	None
512,600	III	Weak	Probably none
747,900	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

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

Albardón in San Juan, Argentina is the nearest significant place from the epicenter. The earthquake occurred 64 kilometer (40 mi) north-northwest of Albardón. The intensity of shaking and damage in Albardón is estimated to be around level IV on the Modified Mercalli Intensity scale (light shaking, likely no damage).

Multiple major population centers exist within 300km of the earthquake that struck today. San Juan is located 74 km to the south-southeast and experienced an intensity of IV (light shaking, likely no damage). Mendoza is located 223 km to the south (intensity unknown, possibly low). La Rioja is located 244 km to the north-east 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)
64 km (40 mi) SSE from epicenter	Albardón San Juan, Argentina.	IV Light
68 km (42 mi) SSE from epicenter	Chimbas San Juan, Argentina.	IV Light
69 km (43 mi) SSE from epicenter	Villa Paula de Sarmiento San Juan, Argentina.	IV Light
72 km (45 mi) N from epicenter	San José de Jáchal San Juan, Argentina.	IV Light
74 km (46 mi) SSE from epicenter	San Juan San Juan, Argentina.	IV Light
75 km (47 mi) SSE from epicenter	Santa Lucía San Juan, Argentina.	IV Light
89 km (55 mi) S from epicenter	Pocito San Juan, Argentina.	IV Light
95 km (59 mi) SSE from epicenter	Caucete San Juan, Argentina.	IV Light
223 km (139 mi) S from epicenter	Mendoza Mendoza, Argentina.
226 km (140 mi) NNE from epicenter	Chilecito La Rioja, Argentina.	III Weak
238 km (148 mi) W from epicenter	Ovalle Coquimbo Region, Chile.
244 km (152 mi) NE from epicenter	La Rioja La Rioja, Argentina.	III Weak
245 km (152 mi) S from epicenter	San Martín Mendoza, Argentina.
246 km (153 mi) WSW from epicenter	Illapel Coquimbo Region, Chile.
265 km (165 mi) WNW from epicenter	La Serena Coquimbo Region, Chile.
271 km (168 mi) WNW from epicenter	Coquimbo Coquimbo Region, Chile.
279 km (173 mi) SW from epicenter	Los Andes Valparaíso, Chile.
280 km (174 mi) SW from epicenter	San Felipe Valparaíso, Chile.
294 km (183 mi) SW from epicenter	La Ligua Valparaíso, Chile.

Earthquake Intensity Map

The graph below overlays a map of the region around the epicenter with earthquake intensity data provided by the US Geographic Survey. The highest intensity level detected 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

Earthquake Intensity Map based on Shakemap Data provided by USGS.

Shaking reported by 22 people in 2 countries

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 22 people have reported shaking in 6 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:

San Juan, San Juan, Argentina: 12 people.
La Serena, Coquimbo, Chile: 3 people.
Santiago, Metropolitana, Chile: 3 people.
Córdoba, Córdoba, Argentina: 2 people.
Vicuña, Coquimbo, Chile: 1 person.
Villa Alemana, Valparaíso, Chile: 1 person.

5 Aftershocks detected

After this earthquake struck, 5 smaller aftershocks occurred. A 3.6 magnitude earthquake hit 3 days later 79 km (49 mi) south of this earthquake.

This main shock was prefaced by 6 smaller foreshocks. Nearby this earthquake a foreshock struck 2 days earlier. It measured a magnitude of 3.6

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
Foreshock	M 3.1	3 days earlier Oct 17, 2024 23:43 (San Juan Time)	81 km (50 mi) SW from Main Shock.
Foreshock	M 3.1	3 days earlier Oct 18, 2024 06:53 (San Juan Time)	69 km (43 mi) SE from Main Shock.
Foreshock	M 3.6	2 days earlier Oct 18, 2024 18:24 (San Juan Time)	56 km (34 mi) SSE from Main Shock.
Foreshock	M 3.1	2 days earlier Oct 18, 2024 22:02 (San Juan Time)	74 km (46 mi) S from Main Shock.
Foreshock	M 3.2	2 days earlier Oct 19, 2024 00:10 (San Juan Time)	65 km (41 mi) S from Main Shock.
Foreshock	M 3.1	1 day earlier Oct 19, 2024 14:08 (San Juan Time)	86 km (54 mi) SE from Main Shock.
Main Shock This Earthquake	M 5.7	Oct 20, 2024 19:59 (San Juan Time)	-
Aftershock	M 3.2	1 day later Oct 22, 2024 00:47 (San Juan Time)	46 km (29 mi) SSE from Main Shock.
Aftershock	M 3.2	2 days later Oct 22, 2024 18:33 (San Juan Time)	79 km (49 mi) S from Main Shock.
Aftershock	M 3.1	2 days later Oct 23, 2024 00:05 (San Juan Time)	83 km (51 mi) S from Main Shock.
Aftershock	M 3.3	2 days later Oct 23, 2024 07:42 (San Juan Time)	82 km (51 mi) SSE from Main Shock.
Aftershock	M 3.6	3 days later Oct 23, 2024 08:06 (San Juan Time)	79 km (49 mi) S 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 21st, 2024, when a 6 magnitude earthquake hit 207 km (129 mi) further east-southeast. An even stronger magnitude 8.3 earthquake struck on September 16th, 2015.

In total, 28 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 4 months.

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 5.7. Earthquakes of this strength are unlikely to trigger a tsunami.	Not this earthquake. This earthquake occurred at a depth of 107 km (67 mi). Earthquakes this deep in the earth are unlikely to trigger a tsunami.

Sources

Last updated 19/12/24 06:08 (). 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.