Tectonic Plates

Costa Rica is located on the overlapping area of the Cocos Tectonic Plate and the Caribbean Plate, which created a convergent boundary. Due to the Cocos Plate moving under the Caribbean Plate, it has resulted in the formation of a volcanic arc in Costa Rica. The subduction zone in Costa Rica is the cause of the volcanic arc, that is shown in the picture to the left. Another effect of these plates is earthquakes, which Costa Rica can experience many earthquakes a year. In 2018, over 200 earthquakes with a magnitude of 3.8 or higher, was recorded in Costa Rica. 

The south-west area of Costa Rica is located near the border of the two tectonic plates. These colliding plates are known as a convergent boundary. The types of plates that are colliding are ocean-continent plates, which means the Cocos Plate is moving under the Caribbean Plate. This type of plate boundary often is the cause of volcanic formation, earthquakes, tsunamis, and flooding.





References:
https://geology.com/volcanoes/arenal/
https://www.volcanodiscovery.com/earthquakes/costarica/archive/2018.html
Keller, Edward A., and Duane Edward DeVecchio. Natural Hazards. 4th ed., Pearson Education,
       2014.