OVSICORI-UNA reported that events at Turrialba at 0600 and 1319 on 8 January generated ash emissions that rose 400-500 m above the crater rim and drifted NW and NE, respectively. An event at 2005 generated an ash plume that rose 800 m above the crater rim and drifted SW. At 0630 on 9 January an ash plume rose 300 m above the crater rim and drifted SW. An event was recorded at 1412, though weather conditions prevented visual conformation.

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)