Magnitude 6.7 Earthquake Strikes Costa Rica — 13th November 2017

A strong magnitude 6.7 earthquake struck Costa Rica on 13th November 2017, shaking large parts of the country and prompting emergency responses across several provinces. The quake occurred near Jacó, a coastal region southwest of the capital San José, and was widely felt throughout Costa Rica as well as parts of Nicaragua and Panama.

Although the earthquake caused no major structural destruction, it resulted in three fatalities, all due to heart attacks triggered during the intense shaking. Several minor injuries and localised damage were reported.

Event Overview

Seismic monitoring agencies recorded the earthquake at a depth of approximately 18–20 km, placing it within the active interplate subduction zone where the Cocos Plate descends beneath the Caribbean Plate. This region is known for producing strong earthquakes due to accumulated tectonic stress.

Key details:

• Magnitude: 6.7 (initially reported between 6.5 and 6.8)
• Date: 13th November 2017
• Depth: ~19 km
• Epicentre: Southeast of Jacó, Pacific coast
• Intensity: Up to MMI VIII (Severe) in localised areas
• Casualties: 3 deaths (heart attacks), at least 2 injuries
• Aftershocks: More than 20 recorded overnight, first at magnitude 5.1 just minutes later

Regional Impact

The strongest shaking was reported in:

• Jacó
• Quepos
• Parrita
• Garabito district

These areas experienced falling objects, cracked walls, and temporary power outages. One building in Jacó was evacuated due to structural concerns, and landslides temporarily blocked sections of the highway connecting Jacó to nearby cities.

In San José, approximately 100 km from the epicentre, shaking reached MMI IV–V, enough for residents to feel strong vibrations and see household items move.

Cause of the Earthquake

Geological analysis confirmed the quake originated from reverse faulting within the Cocos–Caribbean subduction interface, a zone responsible for many of Costa Rica’s strongest earthquakes. Studies of the event show:

• Fault orientation consistent with interplate compression
• Maximum slip around 0.6 m near the centroid
• A rupture radius of approximately 8 km

This region has a history of significant seismicity, including:

• 1990 Cóbano earthquake (M7.0)
• 1999 Quepos earthquake (M6.9)
• 2002 Osa earthquake (M6.4)
• 2004 Damas de Parrita earthquake (M6.4)

Emergency Response

Costa Rica’s emergency agencies activated immediately:

• Hospitals remained fully operational
• Power was restored quickly in affected districts
• No tsunami warning was issued
• Structural inspections were carried out in commercial centres, including Mall San Pedro, which reported wall and floor cracking

Authorities urged residents to remain cautious due to ongoing aftershocks.

Aftershocks

More than 20 aftershocks were recorded within hours of the main event, with the strongest reaching magnitude 5.1 just four minutes later. Most aftershocks occurred within the first 25 km of depth, consistent with typical subduction‑zone behaviour.

Related Guide

What Aftershocks Are and Why They Continue for Weeks or Months

Safety Notes

A magnitude 6.7 earthquake is considered strong, capable of causing:

• Moderate structural damage
• Landslides
• Power outages
• Falling debris

Costa Rica’s robust emergency infrastructure and the quake’s offshore‑adjacent location helped limit serious damage.