Written by on . Last updated March 3rd, 2024.

In the late afternoon of Saturday January 20th, 2024, a strong Magnitude 6.6 earthquake hit under land 139 kilometer from Cruzeiro do Sul in Brazil. Roughly 320 thousand people may have felt this earthquake. Another nearby country is Peru.

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Earthquake Summary

The earthquake struck on land in Brazil, 139 kilometer (86 mi) east-northeast of Cruzeiro do Sul in Acre. The center of this earthquake had a very deep depth of 607 km. Deep earthquakes usually have less impact than shallower earthquakes of similar strenght.

Date and Time: Jan 20, 2024 16:31 (Rio Branco Time)
- Jan 20, 2024 21:31 Universal Time.
Location: 139 km ENE of Cruzeiro do Sul, Acre, Brazil.
Coordinates 7°17'16"S 71°27'50"W.
Map: Map of area around epicenter.
Map of area around epicenter. Click to open in Google Maps.
Magnitude: MAG 6.6
Detected by 18 stations. Maximum Error Range ±0.073 .
Depth: 607 km (377 mi)
A very deep depth.
Max. Intensity:
III
Weak

On the Modified Mercalli Scale.
Tsunami Risk: Tsunami very unlikely
While a very strong earthquake, it appears to have occurred under land.
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 320 thousand people exposed to shaking

This earthquake may have been felt by around 320 thousand 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.

An estimated 30,250 people were exposed to level III. At this level, weak shaking and probably no damage can be expected. Intensity level II was experienced by the majority of people (around 290 thousand). In their region, very weak shaking and no damage can be expected.

People in 2 countries have been exposed to shaking. Roughly 320 thousand people were exposed to shaking in Brazil , with level III (weak shaking, probably no damage) as the highest recorded. In Peru, shaking was experienced too.

People MMI Level Shaking Damage
0
I
Not noticable None
289,800
II
Very weak None
30,250
III
Weak Probably none
0
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

Brazil and Peru are both located within 300km distance of the epicenter of the earthquake. Futher away, this earthquake may also have been felt in Colombia.

Tarauacá in Acre, Brazil is the nearest significant place from the epicenter. The earthquake occurred 124 kilometer (77 mi) northwest of Tarauacá. Tarauacá experienced an earthquake intensity (MMI Scale) of roughly II. That level implies very weak shaking and no 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

Distance Place Intensity (MMI)
124 km (77 mi)
SE from epicenter
Tarauacá

Acre, Brazil.
II
Weak
139 km (86 mi)
WSW from epicenter
Cruzeiro do Sul

Acre, Brazil.
II
Weak
189 km (117 mi)
ENE from epicenter
Eirunepé

Amazonas, Brazil.
II
Weak
360 km (224 mi)
WSW from epicenter
San Fernando

Ucayali, Peru.
361 km (224 mi)
WSW from epicenter
Pucallpa

Ucayali, Peru.
365 km (227 mi)
ESE from epicenter
Sena Madureira

Acre, Brazil.
379 km (235 mi)
NNE from epicenter
Tabatinga

Amazonas, Brazil.
381 km (237 mi)
NNE from epicenter
Leticia

Amazonas, Colombia.
439 km (273 mi)
NNW from epicenter
San Juan

Loreto, Peru.
439 km (273 mi)
NNW from epicenter
Belen

Loreto, Peru.
441 km (274 mi)
NNW from epicenter
Iquitos

Loreto, Peru.
Cities and Towns around the epicenter of this earthquake.

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 III.

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 4 people in 4 countries

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 4 people have reported shaking in 4 places in 4 countries (Brazil, Chile, Colombia, Peru).We keep updating this article as more ground reports become available. You may report that you felt this earthquake here.

Places with most reports:

  • Cruzeiro do Sul, Acre, Brazil: 1 person.
  • Iquique, Tarapacá, Chile: 1 person.
  • Soacha, Cundinamarca, Colombia: 1 person.
  • Lima, Lima Provincias, Peru: 1 person.

Risk of aftershocks?

We monitor for foreshocks or aftershocks that have a magnitude of 2.5+ and occur within 100km (62 mi) of the epicenter of this earthquake. So far no such earthquakes have been detected.

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

Read: How to Stay Safe during an Earthquake (cdc.gov).

This is the strongest earthquake in 5 years

Earthquakes of this strength are not so common in the region, but it's not the first time. This is the strongest earthquake to hit since January 5th, 2019, when a 6.8 magnitude earthquake hit 96 km (60 mi) further south. That was also the heaviest earthquake to hit the region in the past 10 years.

In total, 2 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 5 years.

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.

While MAG-6.5+ earthquakes may cause tsunami's, it appears that the epicenter of this earthquake hit inland, more than 100 km away from coastal areas. In addition, the reported depth is deeper than 100km, making the risk at a tsunami even less likely. 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.
This earthquake had a magnitude of 6.6. Earthquakes of this strength could trigger a tsunami. Not this earthquake.
This earthquake occurred at a depth of 607 km (377 mi). Earthquakes this deep in the earth are unlikely to trigger a tsunami.

Sources

Last updated 03/03/24 03:18 (). 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 us6000m52p
  2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20240120_0000217
  3. Geonames.org: World Cities Database
  4. Google Maps: Static API
  5. Earthquakelist.org: Historic Earthquakes Database

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