OVSICORI-UNA reported that an event at Turrialba on 21 February generated a plume that rose 300 m and drifted NW. Frequent ash pulses were recorded that day. Ash emissions were frequent during 22-24 February, though of variable intensity and duration. Plumes rose as high as 300 m and drifted NW and SW. On 22 February ashfall was reported in Santa Cruz (31 km WSW) and Santa Ana, and a sulfur odor was evident in Moravia (31 km WSW). Cloudy weather conditions prevented visual observations of the vent during 25-26 February.

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)