Earthquakes in Costa Rica are common because the regions unquie structure. four plates converge in the region, the Cocos plate, the Nazca plate, the Caribbean plate and the Panama microplate. Further the thinnest mantle on the globe is found in Costa Rica.
In 2012, the National Seismological Network (RSN) recorded more than 6,000 earthquakes in Costa Rica. Of these, 259 were felt by the people of Costa Rica, this is significantly higher activity than 2011, when it senses 111 events were reported.
Of earthquakes felt in 2012, 159 had magnitudes less than 4.0, 86 and 14 magnitudes between 4 to 4.9 magnitudes greater than or equal to 5.0.
The earthquakes of greater magnitude in 2012 took place in the region of Guanacaste, Central Pacific and the south, mainly because in these regions there were several major events to 5.0 in each.
In the North Pacific (Guanacaste) is located the largest magnitude earthquake of the year was the earthquake of September 5 that was located south of Samara of magnitude Mw 7.6 and associated with the subduction of the Cocos plate.
This earthquake was felt strongly even in most of the country was not as serious damage or deaths to the scale that it did. Of the 259 earthquakes were 117 local earthquakes associated with failures of these was very important activity in the Central Valley triggered by the earthquake of Samara.
The subduction of the Cocos plate under the Caribbean plate and the Panama microplate and some breaks in deeper flaws were responsible for the 142 remaining events most notably the earthquake of September 5, Samara and other earthquakes south of Quepos in February of which the largest had a magnitude of 5.9 Mw.
The Costa Rica News (TCRN)
San Jose Costa Rica