Fumarolic Activity of Avachinsky and Koryaksky Volcanoes, Kamchatka, from 1993 to 1994
Document Type
Article
Publication Date
4-1997
Keywords
Key words Volcanic gases, Vapor-liquid separation, Avachinsky and Koryaksky volcanoes, Kamchatka
Digital Object Identifier (DOI)
https://doi.org/10.1007/s004450050152
Abstract
Volcanic gas and condensate samples were collected in 1993–1994 from fumaroles of Koryaksky and Avachinsky, basaltic andesite volcanoes on the Kamchatka Peninsula near Petropavlovsk–Kamchatsky. The highest-temperature fumarolic discharges, 220 °C at Koryaksky and 473 °C at Avachinsky, are water-rich (940–985 mmol/mol of H2O) and have chemical and isotopic characteristics typical of Kamchatka–Kurile, high- and medium-temperature volcanic gases. The temperature and chemical and water isotopic compositions of the Koryaksky gases have not changed during the past 11 years. They represent an approximate 2 : 1 mixture of magmatic and meteoric end members. Low-temperature, near-boiling-point discharges of Avachinsky Volcano are water poor (≈880 mmol/mol); Their compositions have not changed since the 1991 eruption, and are suggested to be derived from partially condensed magmatic gases at shallow depth. Based on a simple model involving mixing and single-step steam separation, low water and high CO2 contents, as well as the observed Cl concentration and water isotopic composition in low-temperature discharges, are the result of near-surface boiling of a brine composed of the almost pure condensed magmatic gas. High methane content in low-temperature Avachinsky gases and the 220 °C Koryaksky fumarole, low C isotopic ratio in CO2 at Koryaksky (–11.8‰), and water isotope data suggest that the "meteoric" end member contains considerable amounts of the regional methane-rich thermal water discovered in the vicinity of both volcanoes.
Was this content written or created while at USF?
No
Citation / Publisher Attribution
Bulletin of Volcanology, v. 58, issue 6, p. 441-448
Scholar Commons Citation
Taran, Yuri A.; Connor, Charles B.; Shapar, Vyacheslav N.; Ovsyannikov, Alexandre A.; and Bilichenko, Arthur A., "Fumarolic Activity of Avachinsky and Koryaksky Volcanoes, Kamchatka, from 1993 to 1994" (1997). School of Geosciences Faculty and Staff Publications. 1662.
https://digitalcommons.usf.edu/geo_facpub/1662
