OVSICORI-UNA reported that during 15-16 February high-amplitude tremor at Turrialba remained constant, and sporadic gas emissions with minor amounts of ash drifted S and E. Occasional ballistics were ejected from the crater. During 16-17 February sporadic gas emissions with low ash content rose no higher than 300 m and drifted NW and SW. Tremor amplitude had decreased to moderate levels. Similar emissions were observed during 20-21 February, although they drifted NW and NE.

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)