Residents and tourists in the Cobano coastal community of Puntarenas were recently enjoying a pleasant, sunny afternoon when they were suddenly shaken by a strong earthquake that was felt across Costa Rica. It was hardly the first seismic event of 2014, but it was a strong enough reminder about what might be in store for this year.
The epicenter of the January 17th earthquake was about 27.5 kilometers off Montezuma de Cobano, very close to the southern tip of the Nicoya Peninsula. As a result, residents and visitors across Guanacaste were reminded of the September 2012 earthquake in that region. The intensity of the Cobano earthquake was measured as 5.6 on the Richter scale, which makes it the strongest earthquake in Costa Rica thus far in 2014. Fortunately, no major damages or injuries have been reported, but dozens of aftershocks were reported in the following hours.
High Seismicity Zones
The first earthquake of 2014 was felt in the Central Pacific coast, between Quepos and San Marcos. That was on January 5th, and it registered a 3.5 magnitude. So far this year, seismic activity has been felt in the Dota Valley, Guanacaste, Puntarenas, San Ramon, Golfito, Coto Brus, and Cartago.
Earthquakes can strike at just about anytime and anywhere in Costa Rica. They may be of tectonic or volcanic origin. Geologists in Costa Rica have been able to forecast the intensity of future seismic events, but there is no mechanism for predicting earthquakes. However, the Observatory of Seismology and Volcanism of Costa Rica (Spanish acronym: OVSICORI) routinely reviews seismic activities to determine earthquake clusters.
Over the last two years, the Nicoya Peninsula and Guanacaste region have been affected by the ongoing wave of aftershocks produced by the September 2012 earthquake. As the earth below Costa Rica continues to adjust, more earthquakes can be expected in this region.
An earthquake cluster that garnered attention in early 2012 was located in the Orosi Valley of Cartago. This region has once again earned the title of being a seismic hotspot (PDF report) in Costa Rica, with 33 earthquakes ranging between Richter magnitudes of 1.5 to 4. The depths of this cluster range from 1 to 15 kilometers and the seismic faults below are very active. Based on this information, residents and visitors in Cartago and Guanacaste should not be surprised to suddenly feel shaky and aquiver during 2014.