Estimating thermal inflow to El Chichón crater lake using the energy-budget, chemical and isotope balance approaches

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• 作者：Yuri Taran ; Dmitri Rouwet
• 关键词：El Chichó ; n ; crater lake ; mass-energy budget ; CO₂ flux
• 刊名：Journal of Volcanology and Geothermal Research
• 出版年：2008
• 出版时间：20 August 2008
• 年：2008
• 卷：175
• 期：4
• 页码：472-481
• 全文大小：885 K

文摘

El Chichón crater lake appeared immediately after the 1982 catastrophic eruption in a newly formed, 1-km wide, explosive crater. During the first 2 years after the eruption the lake transformed from hot and ultra-acidic caused by dissolution of magmatic gases, to a warm and less acidic lake due to a rapid “magmatic-to-hydrothermal transition” — input of hydrothermal fluids and oxidation of H₂S to sulfate. Chemical composition of the lake water and other thermal fluids discharging in the crater, stable isotope composition (δD and δ¹⁸O) of lake water, gas condensates and thermal waters collected in 1995–2006 were used for the mass-balance calculations (Cl, SO₄ and isotopic composition) of the thermal flux from the crater floor. The calculated fluxes of thermal fluid by different mass-balance approaches become of the same order of magnitude as those derived from the energy-budget model if values of 1.9 and 2 mmol/mol are taken for the catchment coefficient and the average H₂S concentration in the hydrothermal vapors, respectively. The total heat power from the crater is estimated to be between 35 and 60 MW and the CO₂ flux is not higher than 150 t/day or ~ 200 gm^− 2 day^− 1.