A Costa Rican Volcano Sees Its Biggest Blast in Years

Mount Etna spews lava during an eruption on April 11, 2017.Salvatore Allegra/AP Some updates on current volcanic activity worldwide: On April 13, Poás in Costa Rica had its largest explosive eruption in years. The explosion was mainly driven by water heated at the summit crater lake/vent area, generating what is called a "phreatic" eruption. Although water turning to steam is the main player, these explosions can still produce plumes that reach over 1 kilometer (~3,200 feet). This eruption at Poás did just that, with plumes 500 to 1,000 meters tall. News reports also mentioned ash fall in the surrounding region, incandescent blocks suggesting magma relatively close to the surface, and boulders 2 meters wide being thrown from the lake vent. (They broke the floor at the Poas visitor's center!) Passengers on a flight out of San José got quite a view of the eruption. You can watch video of the eruption that was captured by the webcam at Poás. The eruptions have continued, with another blast on April 18.