Keywords
microscopía electrónica de barrido
espectroscopía de rayos-x
erupción freática
erupción freatomagmática
volcán Turrialba
Volcanic Ash
Scanning Electron Microscope
X-Ray Spectroscopy
Phreatic Eruption
Phreatomagmatic Eruption
Turrialba Volcano
How to Cite
Abstract
The Turrialba Volcano is a stratovolcano located approximately 35 km northwest from San José, Costa Rica’s capital city. Since October 29, 2014, until at least late 2015, a series of eruptions has represented the most significant activity of this volcano since the 1860s. These eruptions dispersed a significant volume of ash that reached the most populous areas of the country. In this article, the characteristics of the ash particles are analyzed in order to establish the nature of the eruptive events that occurred on 2014 and 2015, and to monitor the evolution of the eruptive processes. The analysis was carried out utilizing optical microscopy and stereomicroscopy techniques, as well as novel scanning electron microscopy (SEM) methods that involve imaging and element composition analysis by means of Energy Dispersive X-Ray Spectroscopy (EDX). Results show the evolution of the Turrialba eruptions from phreatic events in 2014, with ashes composed entirely of non-juvenile fragments, to phreatomagmatic events starting on March 12, 2015 with the appearance of a significant fraction of juvenile components in the ash.References
INEC, 2011: X Censo Nacional de Poblacióny VI de Vivienda: Resultados Generales.INEC. San José.- 140 págs. Instituto Nacional de Estadística y Censos, San José, Costa Rica [Tech. Rep.].
BARBERI, F., BERTAGNINI, A., LANDI, P. & PRINCIPE, C., 1992: A review on phreatic eruptions and their precursors.- J. Volcanol. Geothermal Res. 52(1992): 231-246, DOI: 10.1016/0377-0273(92)90046-g
BRAGADO-MASSA, E., MARCHAMALO, M., REJAS, J. G., BONATTI, J., MARTÍNEZ-FRÍAS, J. & MARTÍNEZ, R., 2014: Monitoring Hydrothermal alteration in active volcanoes using remote sensing: the case of Turrialba Volcano (Costa Rica).- Rev. Geol. Amér. Central, 51: 69-82, DOI: 10.15517/rgac.v51i1.16848
BROWNE, P. R. L. & LAWLESS, J. V., 2001: Characteristics of hydrothermal eruptions, with examples from New Zealand and elsewhere.- Earth-Science Rev.. 52(4): 299-331, DOI: 10.1016/s0012-8252(00)00030-1
CARR, M. J., 2014: Igpet for Windows.- 64 pp. Terra Softa Inc., Somerset, New Jersey.
LEBAS, M. J., LEMAITRE, R. W., STRECKEISEN, A. & ZANETTIN, B., 1986: A chemical classification of volcanic rocks based on the total alkali-silica diagram.- J. Petrol. 27: 745-750, DOI: 10.1093/petrology/27.3.745
MAHIMAIRAJA, S., BOLAN, N. S., ADRIANO, D. C. & ROBINSON, B., 2005: Arsenic contamination and its risk management in complex environmental settings.- Advances in Agronomy, 86: 1-82, DOI: 10.1016/s0065-2113(05)86001-8
PARDO, N., CRONIN, S. J., NÉMETH, K., BRENNA, M., SCHIPPER, C. I., BREARD, E., WHITE, J. D. L., PROCTER, J., STEWART, B., AGUSTÍN-FLORES, J., MOEBIS, A., ZERNACK, A., KERESZTURI, G., LUBE, G., AUER, A., NEALL, V. & WALLACE, C., 2014: Perils in distinguishing phreatic from phreatomagmatic ash; insights into the eruption mechanisms of the 6 August 2012 Mt. Tongariro eruption, New Zealand.- J. Volcanol. Geothermal Res. 286(2014): 397-414, DOI: 10.1016/j.jvolgeores.2014.05.001
REAGAN, M. K., DUARTE, E., SOTO, G. J. & FERNANDEZ, E., 2006: The eruptive history of Turrialba volcano, Costa Rica, and potential implication hazard from future eruptions.- Geol. Soc. Amer. Spec. Paper. 412: 235-257.
RECIO, P., 2015: Aeropuerto Juan Santamaría permanece cerrado hasta este viernes a las 8 a.m.- La Nación [online], http://www.nacion.com/nacional/transportes/Cierran-Aeropuerto-Juan-Santamaria-ceniza_0_1474852642.html [Consulted: 21 July, 2015].
REED, S. J. B., 2006: Electron Microprobe Analysis and Scanning Electron Microscopy in Geology.- 192 pp. Cambridge University Press, United Kingdom.
ROUWET, D., SANDRI, L., MARZOCCHI, W., GOTTSMANN, J., SELVA, J., TONINI, R. & PAPALE, P., 2014: Recognizing and tracking volcanic hazards related to non-magmatic unrest: a review.- J. Applied Volcanol. 3(17): 1-17, DOI: 10.1186/s13617-014-0017-3
ROY, P. & SAHA, A., 2002: Metabolism and toxicity of arsenic: A human carcinogen.- Current Sci. 82(1): 38-45.
RUÍZ, P., 2012: Reconstruction of the paleo and neo stages of Poás and Turrialba volcanoes, Costa Rica: Competing processes of growth and destruction.- 174 págs. Rutgers University, New Brunswick, New Jersey [Tesis Ph.D].
SMEDLEY, P. & KINNIBURGH, D., 2002: A review of the source, behaviour and distribution of arsenic in natural waters.- Applied Geochem. 17(5): 517-568.
SOTO, G. J., 1988: Geología y vulcanología del volcán Turrialba, Costa Rica.- Costa Rican Volcanism Workshop, Washington, D.C. and Shenandoah National Park: 18.
SOTO, G. J. & MORA, M., 2012: Actividad del volcán Turrialba en el periodo 2007-2011 y perspectivas de su amenaza.- In: ADAMSON, M. & CASTILLO, F. (eds): Desastres: Costa Rica en el tercer milenio desafíos y propuestas para la reducción de vulnerabilidad.- Contrastes Vivos de Costa Rica, San José: 287-310.