Shallow M5.6 Earthquake struck on Wednesday Afternoon in the North Pacific Ocean 266km from San José (Costa Rica).

Written by Earthquakelist.org on September 30th, 2026. Last updated October 1st, 2026.

In the North Pacific Ocean 266 kilometer from San José, Costa Rica, a shallow and significant MAG-5.6 earthquake occurred in the afternoon of Wednesday September 30th, 2026. Around 100 thousand people have been exposed to shaking. Nicaragua is also near its epicenter.

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Earthquake Summary

This earthquake hit under water in the North Pacific Ocean, 88 kilometers (55 mi) off the coast of Costa Rica, 266 kilometer west of San José. The center of this earthquake had a very shallow depth of 8 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Sep 30, 2026 03:55PM (Costa Rica Time) - Sep 30, 2026 21:55 Universal Time.
Location:	266 km south of Managua, Nicaragua. Coordinates 9°45'9"N 86°30'23"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.6 Detected by 27 stations. Maximum Error Range ±0.06 .
Depth:	8 km (5 mi) A very shallow depth.
Max. Intensity:	IV Light On the Modified Mercalli Scale.
Tsunami Risk:	Low tsunami risk Earthquakes under MAG-6.5 do not usually 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 100 thousand people exposed to shaking

This earthquake may have been felt by around 100 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.

The highest earthquake impact level for this earthquake is IV, which corresponds with light shaking and likely no damage. Roughly 36,090 people are expected to be exposed to this level. Intensity level III was experienced by the majority of people (around 60 thousand). In their region, weak shaking and probably no damage can be expected.

People in 2 countries have been exposed to shaking. In Costa Rica , around 100 thousand people, with impact levels up to IV (light shaking, likely no damage). Shaking was experienced by inhabitants of Nicaragua too.

Nearby towns and cities

Costa Rica and Nicaragua are both located within 300km distance of the epicenter of the earthquake.

Located 124 kilometer (77 mi) west of the epicenter of this earthquake, Nicoya (Guanacaste, Costa Rica) is the nearest significant population center.

Major cities near this earthquake: Managua is located 266 km to the north. San José is located 266 km to the east. Masaya is located 251 km to the north.

The table below provides an overview of all places in proximity of today's earthquake.

Overview of nearby places

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

Shaking reported by 3 people

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 3 people have reported shaking in 2 places in Costa Rica.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 Rafael, San José, Costa Rica: 2 people.
• Sardinal, Guanacaste, Costa Rica: 1 person.

2 Aftershocks detected

Since this main shock, 2 smaller aftershocks were detected. A 3.5 magnitude earthquake hit 33 mins later 6 km (3 mi) south-east of this earthquake.

This main shock was prefaced by 2 smaller foreshocks. Nearby this earthquake a foreshock struck 1 day earlier. It measured a magnitude of 2.7

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.

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

Earthquakes like this are common in the region

Earthquakes of this strength occur quite regularly in the region. This is the strongest earthquake to hit since April 15th, 2026, when a 5.7 magnitude earthquake hit 22 km (14 mi) further north-east. An even stronger magnitude 6.6 earthquake struck on April 21st, 2022.

In total, 12 earthquakes with a magnitude of 5.6 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 10 months.

Low tsunami risk

Based on early data it appears this earthquake was not strong enough (lower than MAG-6.5) to be likely to cause destructive tsunami's. However this earthquake appeared to have hit at a shallow depth under sea, so stay cautious and monitor advice from local authorities.

Tsunami Risk Factors

Sources

Last updated 01/10/26 22:18 (). 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 us6000tymj
2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20260930_0000275
3. Geonames.org: World Cities Database
4. Google Maps: Static API
5. Earthquakelist.org: Historic Earthquakes Database

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