OVSICORI-UNA reported that an ash emission from Turrialba occurred at 1520 on 14 May and drifted W. An eruption that started at 1018 on 18 May, and lasted for 23 minutes, generated an ash plume that rose 400 m above the crater and drifted NW. Another ash emission from a 25-minute-long eruption, which began at 1350, rose 500 m and drifted NW. At 1549 a third ash emission drifted NNW at an unknown altitude due to cloudy conditions.

Geological Summary. Turrialba, the easternmost of Costa Rica's Holocene volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano located across a broad saddle NE of Irazú volcano overlooking the city of Cartago. The massive edifice covers an area of 500 km2. Three well-defined craters occur at the upper SW end of a broad 800 x 2200 m summit depression that is breached to the NE. Most activity originated from the summit vent complex, but two pyroclastic cones are located on the SW flank. Five major explosive eruptions have occurred during the past 3500 years. A series of explosive eruptions during the 19th century were sometimes accompanied by pyroclastic flows. Fumarolic activity continues at the central and SW summit craters.

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)