Costa Rica could experience more tremors in the coming days and weeks as Panama continues to record aftershocks from yesterday’s powerful magnitude 7.7 earthquake. Seismologists say some of those aftershocks could be strong enough to be felt across the country, particularly in southern communities near the Panamanian border.
Panama’s Geosciences Institute has recorded more than 100 aftershocks since the earthquake struck yesterday at 11:56 a.m. Costa Rica time. The institute’s director, Néstor Luque, reported approximately 107 aftershocks as monitoring continued into today. Leopold Linkimer, a seismologist with the University of Costa Rica’s National Seismological Network (RSN), warned that significant aftershocks could continue for hours, days, weeks or even months.
The warning comes after yesterday’s earthquake shook much of Costa Rica, sending people out of homes and offices from the Southern Zone to the Central Valley. The earthquake was centered on Panama’s Azuero Peninsula, approximately 12 kilometers (7 miles) west-southwest of Pitaloza Arriba.
Several aftershocks followed within hours. One of the strongest occurred at approximately 2:25 p.m. yesterday, registering magnitude 6.6 according to Costa Rica’s RSN. That earthquake was also felt throughout Costa Rica. The concern now is how long the activity might continue and whether another strong earthquake could affect Costa Rican communities.
Linkimer explained that large earthquakes can disturb surrounding areas underground, sometimes setting off additional earthquakes as the Earth’s crust adjusts to the sudden movement. These smaller earthquakes are called aftershocks, and they are a normal part of what happens after a major earthquake.
The U.S. Geological Survey says aftershocks generally become less frequent over time. Most occur shortly after the main earthquake, but some can continue for months or even years following an especially powerful event. That does not mean every new earthquake will necessarily be weaker than the one before it. Strong aftershocks can still occur as the overall number of earthquakes gradually declines.
For Costa Rica, there is another possibility scientists are watching. Linkimer said the movement caused by Panama’s earthquake could potentially affect faults within Costa Rican territory. A fault is a break in the Earth’s crust where sections of rock can move, sometimes producing an earthquake.
A powerful earthquake can change pressure along nearby faults, occasionally causing movement in areas outside the original earthquake zone. However, Linkimer emphasized that this does not happen after every major earthquake. The possibility of additional activity in Costa Rica does not mean another destructive earthquake is expected.
Scientists cannot predict exactly when or where the next significant earthquake will occur. Another issue for everyone is the reliability of earthquake alerts. The Volcanological and Seismological Observatory of Costa Rica (OVSICORI) explained that its earthquake warning application did not issue an alert for yesterday’s main earthquake because the epicenter was outside the geographic area covered by the system’s early warning settings.
Walter Jiménez, a seismic analyst with OVSICORI, explained that Costa Rican monitoring equipment is better able to detect larger earthquakes occurring in Panama. Smaller aftershocks can be difficult to identify because of their distance from Costa Rican monitoring stations.
As a result, you should not assume that earthquake activity has stopped simply because they are no longer receiving notifications. The earthquakes have caused considerably more damage in Panama than in Costa Rica. Panamanian authorities reported at least 27 people with minor injuries, approximately 300 evacuations and damage to more than 400 buildings, including homes and schools. No deaths had been confirmed in their latest reported assessment.
Costa Rica’s National Emergency Commission (CNE) reported no severe damage following yesterday’s initial earthquake, although the Red Cross confirmed that small objects had fallen in some southern communities. The earthquake also disrupted regional air travel. Tocumen International Airport temporarily suspended flights yesterday, affecting passengers traveling between Costa Rica, Panama and international destinations. Operations resumed after safety inspections, but travelers with connections through Panama should continue checking directly with their airlines for schedule changes.
Costa Rica’s National Tsunami Monitoring System ruled out a tsunami threat from yesterday’s initial earthquake. However, any future major earthquake would require a separate assessment. For everyone here you should stay prepared without assuming another major earthquake is coming.
The CNE recommends having a family emergency plan, identifying safe places inside homes and businesses, and knowing evacuation procedures. During an earthquake, people indoors should generally drop to the ground, take cover beneath sturdy furniture and hold on until the shaking stops. Everyoe should also check for signs of structural damage afterward and avoid entering buildings that appear unsafe.
People living along the Pacific coast should know their tsunami evacuation routes. Strong or prolonged shaking near the beach is a reason to move inland or to higher ground once it is safe to do so, without waiting for an official warning. Costa Rican and Panamanian seismologists will continue monitoring the activity as the region adjusts to yesterday’s earthquake.
Although the number of aftershocks is expected to decline, scientists say everyone here should be prepared for the possibility of additional tremors over the coming weeks and months.
