Real-time coverage of earthquake event — 72 km SW of Tamarindo, Costa Rica — Pandita Data.
🌍 OPEN LIVE 3D EARTHQUAKE MAPA magnitude 5.7 earthquake struck 72 kilometres southwest of Tamarindo, Costa Rica, on April 15, 2026, at 06:56 UTC, with rupture initiating at 20 kilometres depth. The US Geological Survey issued a GREEN PAGER alert—indicating minimal economic loss and few casualties expected—though the shallow focal depth and proximity to populated Pacific coastal zones warranted immediate seismic assessment. Thirty-four people reported feeling the tremor across Guanacaste Province, the nearest major population centre. No tsunami warning was issued by the Pacific Tsunami Warning Centre; however, the moderate magnitude and shallow geometry produced significant ground acceleration across the epicentral region.
Costa Rica sits along the Central American Volcanic Arc, where the Cocos Plate subducts beneath the Caribbean Plate at a rate of approximately 9.2 centimetres per year. This earthquake occurred within the subducting Cocos Plate slab, roughly 70 kilometres landward of the Middle America Trench. The Tamarindo region experiences frequent intermediate-depth seismicity driven by slab bending and dehydration reactions within the descending oceanic lithosphere. Unlike megathrust earthquakes at the plate interface, intraslab ruptures like this one typically produce narrower damage zones but can trigger strong motion in coastal communities due to efficient seismic wave propagation through intact oceanic crust.
At 20 kilometres depth, this rupture occurred in the upper, brittle portion of the Cocos slab where stress accumulation and elastic rebound drive rapid slip. A magnitude 5.7 earthquake releases approximately 5.6 × 1018 joules of energy—roughly equivalent to 1.3 megatons of TNT. Shallow earthquakes radiate energy more efficiently to the surface than deeper events; the proximity of this rupture to the crust–slab interface means high-frequency seismic waves reach coastal populations with minimal attenuation, producing perceptible shaking across distances exceeding 200 kilometres.
Focal Depth 20 km: Within the elastic core of the subducting plate. Rupture nucleation and propagation occur through intact oceanic crust with high rigidity, permitting efficient elastic wave transmission. Ground accelerations typically exceed 0.1 g within 80 kilometres of the epicentre. The USGS Modified Mercalli Intensity scale predicts shaking of V–VI (Moderate to Strong) in Tamarindo and coastal Guanacaste, sufficient to knock objects from shelves and cause minor structural damage to unreinforced masonry.
Tamarindo, Flamingo, and Nosara—Pacific resort towns with growing residential and tourism infrastructure—experienced the strongest ground motion. Historic seismicity in the region includes a magnitude 6.3 event in 1991 (Limón earthquake), which caused widespread damage across Costa Rica and killed 75 people. The 2026 earthquake's M5.7 magnitude and 20-kilometre depth placed it below the threshold for significant structural failure in modern, code-compliant buildings, but older constructions and non-engineered structures remain vulnerable. The Green PAGER classification reflects low expected casualties given building standards and population distribution, though emergency services mobilised precautionary inspections of hospitals, schools, and critical infrastructure.