Report on Turrialba (Costa Rica) — May 1993
Bulletin of the Global Volcanism Network, vol. 18, no. 5 (May 1993)
Managing Editor: Edward Venzke.
Turrialba (Costa Rica) Seismic activity continues
Please cite this report as:
Global Volcanism Program, 1993. Report on Turrialba (Costa Rica). In: Venzke, E (ed.), Bulletin of the Global Volcanism Network, 18:5. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199305-345070.
10.025°N, 83.767°W; summit elev. 3340 m
All times are local (unless otherwise noted)
A seismograph 0.5 km E of the active crater recorded 18 low-frequency events during May. Seismicity has remained at approximately the same level for the past year. There were 17 low-frequency events recorded in June 1992, 6 in July, 14 in August, and 13 in September (17:6-9). Tilt measurements reported in January revealed no changes since 1982 (18:01). Fumarolic activity and landslides from the main crater walls were continuing in April (18:04).
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.
Information Contacts: E. Fernández, J. Barquero, F. De Obaldía, T. Marino, R. Van Der Laat, V. Barboza, and R. Saenz, OVSICORI.