Report on Turrialba (Costa Rica) — 12 December-18 December 2018
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 12 December-18 December 2018
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2018. Report on Turrialba (Costa Rica). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 12 December-18 December 2018. Smithsonian Institution and US Geological Survey.
10.025°N, 83.767°W; summit elev. 3340 m
All times are local (unless otherwise noted)
OVSICORI-UNA reported semi-continuous activity at Turrialba during 11-16 December. Ash emissions rose as high as 500 m above the vent rim and drifted NW and SW during 11-12 December. Ashfall was reported in Guadalupe (32 km WSW) on 13 December. Pulsing ash emissions were visible on 13 December and caused ashfall in areas of Valle Central. During 14-16 December emissions had diffuse amounts of ash and drifted W and SW.
Geologic Background. 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.