DOI: 10.1016/j.epsl.2018.06.011
Scopus记录号: 2-s2.0-85048936616
论文题名: Chlorate brines on Mars: Implications for the occurrence of liquid water and deliquescence
作者: Toner J.D. ; Catling D.C.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 497 起始页码: 161
结束页码: 168
语种: 英语
英文关键词: chlorate salts
; deliquescence
; isopiestic
; liquid water
; Mars
; water activity
Scopus关键词: Chlorine compounds
; Inorganic compounds
; Liquids
; Salts
; Solubility
; Thermodynamic properties
; deliquescence
; isopiestic
; Liquid water
; Mars
; Water activity
; Magnesium compounds
英文摘要: Oxychlorine salts (chlorates and perchlorates) are globally important components of surface soils on Mars, and could form liquid water in concentrated salt solutions despite prevailing cold and dry conditions. Although perchlorate salts are well-characterized, basic thermodynamic properties of chlorate solutions, such as water activity (aw) and even solubility, are poorly known. To address this knowledge-gap, we measured water activities and solubilities in the Na–Ca–Mg–ClO3 system at 25 °C using the isopiestic method, and fit the data to an aqueous ion-interaction Pitzer model. We find that chlorate solutions have extremely low water activities that could allow liquid water to form on the surface of Mars. Compared to perchlorates, chlorates generally have higher water activities at the same concentration; however, saturated Mg(ClO3)2 solutions, in particular, are extremely concentrated (7.59 mol kg−1) and have aw=0.2 at 25 °C, substantially below saturated Mg(ClO4)2 solutions (aw=0.4). If Mg(ClO3)2 salts are present on Mars’ surface, then our results suggest a much greater potential for liquid water formation in soils due to freezing point depression or deliquescence than with perchlorates. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109780
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: University of Washington, Dept. Earth & Space Sciences, Box 351310, Seattle, WA 98195, United States
Recommended Citation:
Toner J.D.,Catling D.C.. Chlorate brines on Mars: Implications for the occurrence of liquid water and deliquescence[J]. Earth and Planetary Science Letters,2018-01-01,497