Report on Turrialba (Costa Rica) — 12 July-18 July 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 12 July-18 July 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Turrialba (Costa Rica). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 12 July-18 July 2017. 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 eruptive events at Turrialba daily during 12-17 July. Gas and ash plumes rose 200-500 m above the vent and generally drifted NW, W, and SW. There were multiple events on 15 July, causing ashfall in Sabanilla de Montes de Oca (30 km WSW), Ipis (27 km SW), El Carmen de Guadalupe, Purral (26 km WSW), Guadalupe (32 km WSW), and Tibás (35 km WSW). A sulfur dioxide odor was also reported that day, in San José (36 km WSW), Tibas (35 km WSW), Guadalupe, Escazú (42 km WSW), and Puriscal (65 km WSW).
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.