HR: 1400h
AN: V43A-05    [Abstracts]
TI: 20 months of sustained changes at Turrialba volcano. Visual changes.
AU: * Duarte, E
EM: eduarte@una.ac.cr
AF: OVSICORI-UNA Costa Rica, Campus Heredia Costa Rica, Heredia, 3000, Costa Rica
AU: Fernandez, E
EM: efernan@una.ac.cr
AF: OVSICORI-UNA Costa Rica, Campus Heredia Costa Rica, Heredia, 3000, Costa Rica
AU: Saenz, W
EM: wsaenz@una.ac.cr
AF: OVSICORI-UNA Costa Rica, Campus Heredia Costa Rica, Heredia, 3000, Costa Rica
AU: Martinez, M
EM: mmartine@una.ac.cr
AF: OVSICORI-UNA Costa Rica, Campus Heredia Costa Rica, Heredia, 3000, Costa Rica
AU: Barboza, V
EM: vbarboza@una.ac.cr
AF: OVSICORI-UNA Costa Rica, Campus Heredia Costa Rica, Heredia, 3000, Costa Rica
AB: Turrialba Volcano (3340 m) is located at the southern end of the Mesoamerican Volcanic Arc. The summit area has three craters aligned NE-SW: East, Central and West craters. The last active period of Turrialba Volcano occurred between 1864-1866. During this period, the West crater of Turrialba was formed and ash falls were reported in the Central Valley of Costa Rica. Mild to moderate fumarolic activity has been present at Turrialba volcano, Central and West craters, since 1866. This volcano has shown a variety of activity peaks during the last 10 years, mainly seismic swarms and vigorous gas activity. Furthermore, at the middle of 2005 one of the greater degassing events took place provoking serious effects on vegetation and expanding fumaroles towards the W and NW edges of the caldera. Cracks around these sectors are releasing unestimated amounts of gas and vapor. Rapid sedimentation in the bottom of W crater has been also reported. Enrichment of routinely sampled fumaroles make gas sampling process more difficult. Expansion of heated ground around the W crater is accompanied by deposition of sulphur salts and other sulphur-relative deposits. Rapid erosion of the W crater accompanied of yet more vigorous degassing has sustained all through 2006. On august a report was given to the national and international community due to the rapid burning and death of major tree species. Most of dwarf vegetation and small vegetation coverage is rapidly disappearing thus affecting directly the fragile balance between flora and fauna. Disorders in the feeding and behavior of a community of coyotes has been observed, always related to acute impact of volcanic activity. More changes in other species that inhabit the summit areas are expected. Moreover, pressure and impact on settlers, living in the low lands around the volcano, is also expected. A poster will illustrate areas of gas expansion, physical instability and sedimentation. It will also show areas where major impact on vegetation and fauna is taking place.
UR: http:www.ovsicori.una.ac.cr
DE: 0370 Volcanic effects (8409)
DE: 1011 Thermodynamics (0766, 3611, 8411)
DE: 1034 Hydrothermal systems (0450, 3017, 3616, 4832, 8135, 8424)
DE: 8485 Remote sensing of volcanoes
SC: Volcanology, Geochemistry, and Petrology [V]
MN: 2007 Joint Assembly