Costa Rica's Earthquakes
For more than a year after I had moved to Costa Rica, I didn’t feel one earthquake or tremor; either they were too weak for me to register, or they occurred while I was sleeping. When I finally felt my first minor quake, I flew down the steps to celebrate with a visiting Costa Rican friend – I was one step close to experiencing all of Costa Rica!
Flanked by active tectonic plates on both the Pacific and Caribbean coasts, Costa Rica is one of the most earthquake prone countries in the world. The Caribbean and the Cocos Plate are in constant motion, and when they pull apart or collide, they release geological forces, causing minor tremors to full-scale quakes. There are also 51 faults located throughout the country. Ranging in size from minute to large, faults form the boundaries for tectonic plates. When faults experience sudden movement, released energy can also create earthquakes.
Thankfully, most earthquakes in Costa Rica are minor, registering below a 5.0 magnitude. One factor that affects an earthquake’s strength above ground is the depth at which it occurs; the more shallow the fault line, the stronger it will feel to you. In 2010, the Costa Rican Volcanology and Seismology Institute recorded 111 quakes, ranging in magnitude from 1.5 to 6.2, and from .62 to 62 miles in depth.
In Spanish, earthquakes are known as temblores, or tremors, and are a minor inconvenience, mostly causing small ground vibrations. There’s no one way to experience a tremor: they can cause a rolling sensation, as if you were on a mini roller coaster, or a gentle vibration, like when your downstairs neighbors have the bass turned up too high.
In the last 100 years, Costa Rica has only experienced five major earthquakes, the most recent in 2009. Known as the Cinchona earthquake, it occurred near Poas Volcano, and registered a 6.1 magnitude at 2.8 miles below the ground. An estimated 34 lives were lost during the disaster, mostly due to substandard construction that was not earthquake-resistant. (Today, all new construction is required to meet strict safety controls and seismic standards.)
During a major earthquake, known as a terremoto, you will feel significant ground movement, and items will likely fall off of walls and shelves. Though strong earthquakes are rare, it’s best to prepare in advance. Secure large bookcases and display shelves to the wall, and store breakables on shelves with a small lip. In the event of an earthquake, authorities recommend that you do not run for cover, as most injuries occur when people inside attempt to move to a different location. Instead, crawl underneath a table or desk, or simply drop to the ground and cover your head until the shaking stops. The natural forces that make Costa Rica so incredibly beautiful are still hard at work, so it’s always good to be prepared.