Silicon tetrafluoride on Io

被引：12

作者：

Schaefer, L ^{[1
]}

Fegley, B ^{[1
]}

机构：

[1] Washington Univ, Dept Earth & Planetary Sci, Planetary Chem Lab, St Louis, MO 63130 USA

来源：

ICARUS | 2005年 / 179卷 / 01期

基金：

美国国家航空航天局;

关键词：

Io; volcanic gases; silicon; fluorine; silicon tetrafluoride; condensates; geochemistry; atmospheric chemistry;

D O I：

10.1016/j.icarus.2005.05.020

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Silicon tetrafluoride (SiF4) is observed in terrestrial volcanic gases and is predicted to be the major F-bearing species in low-temperature volcanic gases on Io [Schaefer, L., Fegley Jr., B., 2005b. Alkali and halogen chemistry in volcanic gases on Io. Icarus 173, 454-468]. SiF4 gas is also a potential indicator of silica-rich crust on to. We used F/S ratios in terrestrial and extraterrestrial basalts, and gas/lava enrichment factors for F and S measured at terrestrial volcanoes to calculate equilibrium SiF4/SO2 ratios in volcanic gases on to. We conclude that SiF4 can be produced at levels comparable to the observed NaCI/SO2 gas ratio. We also considered potential loss processes for SiF4 in volcanic plumes and in Io's atmosphere including ion-molecule reactions, electron chemistry, photochemistry, reactions with the major atmospheric constituents, and condensation. Photochemical destruction (t(chem) similar to 266 days) and/or condensation as Na2SiF6 (s) appear to be the major sinks for SiF4. We recommend searching for SiF4 with infrared spectroscopy using its 9.7 mu m band as done on Earth. (c) 2005 Elsevier Inc. All rights reserved.

引用

页码：252 / 258

页数：7

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