OVSICORI-UNA reported that an event at Turrialba at 1607 on 9 August generated a plume that rose 200 m above the crater rim and drifted NW. The report noted that since 6 August a monitoring station in Coronado San José had been detecting the presence of ash in emissions. Sporadic and passive emissions of ash, water vapor, magmatic gases, and aerosols continued to be observed at least through 14 August.

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)