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  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 10.748°N
  • 85.153°W

  • 2028 m
    6652 ft

  • 345030
  • Latitude
  • Longitude

  • Summit

  • Volcano

There are no activity reports for Miravalles.

 Available Weekly Reports

There are no Weekly Reports available for Miravalles.

Summary of eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1946 Sep 14 1946 Sep 14 Confirmed 1 Historical Observations SW flank (near Las Hornillas)
5050 BCE (?) Unknown Confirmed   Tephrochronology

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Alvarado G E, 1989. Los Volcanes de Costa Rica. San Jose, Costa Rica: Universidad Estatal a Distancia, 175 p.

Alvarado G E, 2000. Volcanes de Costa Rica: su geologia, historia y riqueza natural. San Jose, Costa Rica: EUNED, 269 p.

Alvarado G E, Kussmaul S, Chiesa S, Gillot P-Y, Appel H, Worner G, Rundle C, 1992. Resumen cronoestratigrafico de las rocas igneas de Costa Rica basado en dataciones radiometricas. J South Amer Earth Sci, 6: 151-168.

Alvarado G E, Vega E, Chaves J, Vasquez M, 2004. Los grandes deslizamientos (volcanicos y no volcanicos) de tip debris avalanche en Costa Rica. Rev Geol Amer Central, 30: 83-99.

Alvarado-Induni G E, 2005. Costa Rica, Land of Volcanoes. San Jose, Costa Rica: EUNID, 306 p.

Barquero-H J, Saenz-R R, 1987. Aparatos volcanicos de Costa Rica. Heredia, Costa Rica: OVSICORI-UNA, 1:750,000 map and volcano list.

Carr M J, 1984. Symmetrical and segmented variation of physical and geochemical characterisitics of the Central American volcanic front. J Volc Geotherm Res, 20: 231-252.

Chiesa S, Alvarado G E, Pecchio M, Corella M, Zanchi A, 1994. Contribution to petrological and stratigraphical understanding of the Cordillera de Guanacaste lava flows, Costa Rica. Rev Geol Amer Central, 17: 19-43.

Chiesa S, Civelli G, Gillot P-Y, Mora A, Alvarado G E, 1992. Rocas piroclasticas asociadas con la formacion de la caldera de Guayabo, Cordillera de Guanacaste, Costa Rica. Rev Geol Amer Central, 14: 59-75.

Hallinan S, 1993. Nonchaotic collapse at funnel calderas; gravity study of the ring fractures at Guayabo caldera, Costa Rica. Geology, 21: 367-370.

Hallinan S, Brown G, 1995. Incremental collapse and stratocone growth within a funnel-shaped caldera, Guayabo, Costa Rica. J Volc Geotherm Res, 67: 101-122.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

Mainieri P A, 2003. Costa Rica geothermal update. Geotherm Res Council Bull, 32: 157-158.

Mainieri P A, 1976. Proyecto geotermico de Guanacaste: informe de previabilidad tecnica. Inst Costarricense de Electricidad (ICE), 97 p.

Marini L, Yock Fung A, Sanchez E, 2003. Use of reaction path modeling to identify the process governing the generation of netrual Na-Cl and acidic Na-Cl-SO4 deep geothermal liquids at Miravalles geothermal system, Costa Rica. J Volc Geotherm Res, 128: 363-387.

Mooser F, Meyer-Abich H, McBirney A R, 1958. Central America. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 6: 1-146.

Newhall C G, Dzurisin D, 1988. Historical unrest at large calderas of the world. U S Geol Surv Bull, 1855: 1108 p, 2 vol.

Siebert L, Alvarado G E, Vallance J W, van Wyk de Vries B, 2006. Large-volume volcanic edifice failures in Central America and associated hazards. In: Rose W I, Bluth G J S, Carr M J, Ewert J W, Patino L C, Vallance J W (eds), Volcanic hazards in Central America, {Geol Soc Amer Spec Pap}, 412: 1-26.

Vega Zuniga E, Chavarria Rojas L, Barrantes Viquez M, Molina Zuniga F, Hakanson E C, Mora Protti O, 2005. Geologic model of the Miravalles geothermal field, Costa Rica. Proc World Geotherm Cong 2005, Antalya, Turkey, 24-29 April 2005 CD-ROM, 5 p.

Miravalles is a 2028-m-high andesitic stratovolcano that is one of five post-caldera cones along a NE-trending line within the broad 15 x 20 km Guayabo (Miravalles) caldera. The caldera was formed during several major explosive eruptions that produced voluminous dacitic-rhyolitic pyroclastic flows between about 1.5 and 0.6 million years ago. Growth of post-caldera volcanoes in the eastern part of the caldera that overtopped much of the eastern and southern caldera rims was interrupted by edifice collapse that produced a major debris avalanche to the SW. Morphologically youthful lava flows cover the western and SW flanks of the post-caldera Miravalles complex, which rises above the town of Guayabo on the flat western caldera floor. The only reported historical eruptive activity was a small steam explosion on the SW flank in 1946. High heat flow remains, and Miravalles is the site of the largest developed geothermal field in Costa Rica.