Earthquakes in Costa Rica: Live Map & the Nicoya Seismic Gap

Costa Rica sits directly above the Middle America Trench, where the Cocos plate subducts beneath the Caribbean plate at one of the fastest rates in the region — roughly 8 to 9 centimetres a year in places. That rapid convergence makes Costa Rica one of the most seismically active countries in Central America, with earthquakes recorded somewhere in the country almost every day.

Costa Rica is also a rare scientific success story in earthquake forecasting. For decades, seismologists at the Volcanological and Seismological Observatory of Costa Rica (OVSICORI-UNA) had identified the Nicoya Peninsula as a mature 'seismic gap' — a locked patch of the subduction interface overdue to rupture. On 5 September 2012, it did: a magnitude 7.6 earthquake struck almost exactly where forecast, and thanks to dense instrumentation, strict building codes and a mostly rural epicentre, it caused remarkably few deaths for its size.

San José, the capital, sits inland in the Central Valley and generally experiences more moderate shaking than the Pacific coast. Costa Rica's National Seismological Network (Red Sismológica Nacional) and OVSICORI maintain one of the densest monitoring networks in Latin America, and the country has invested heavily in seismic-resistant construction, which is a major reason its earthquake death toll stays low despite very high seismic activity.