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Read Full Article (file size: 192329 bytes) Cited by
GEOPHYSICAL RESEARCH LETTERS,
VOL. 34,
L11202,
doi:10.1029/2006GL029156,
2007
Salinity-induced hydrate dissociation: A mechanism for recent CH4 release on Mars
M. E. Elwood Madden
Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
S. M. Ulrich
Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
T. C. Onstott
Department of Geosciences, Princeton University, Princeton, New Jersey, USA
T. J. Phelps
Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
Abstract
Recent observations of CH4 in the Martian atmosphere suggest that CH4 has been added relatively recently. Several mechanisms for recent CH4 release have been proposed including subsurface biological methanogenesis, abiogenic hydrothermal and/or volcanic activity,
dissociation of CH4 hydrates, atmospheric photolysis, or addition of organics via bolide impact. This study examines the effects of increasing
salinity on gas hydrate stability and compares estimates of the Martian geothermal gradient to CH4 and CO2 hydrate stability fields in the presence of high salinity brines. The results demonstrate that salinity increases alone result
in a significant decrease in the predicted hydrate stability zone within the Martian subsurface and may be a driving force
in CH4 hydrate destabilization. Active thermal and/or pressure fluctuations are not required in order for CH4 hydrates to be the source of atmospheric CH4.
Received 20
December
2006;
accepted 7
May
2007;
published 8
June
2007.
Keywords: Mars;
methane;
hydrate.
Index Terms: 1060 Geochemistry: Planetary geochemistry (5405, 5410, 5704, 5709, 6005, 6008); 3004 Marine Geology and Geophysics: Gas and hydrate systems; 5210 Planetary Sciences: Astrobiology: Planetary atmospheres, clouds, and hazes (0343); 5220 Planetary Sciences: Astrobiology: Hydrothermal systems and weathering on other planets; 6225 Planetary Sciences: Solar System Objects: Mars.
Read Full Article (file size: 192329 bytes) Cited by
Citation: Elwood Madden, M. E., S. M. Ulrich, T. C. Onstott, and T. J. Phelps
(2007),
Salinity-induced hydrate dissociation: A mechanism for recent CH4 release on Mars,
Geophys. Res. Lett.,
34,
L11202,
doi:10.1029/2006GL029156.
Copyright 2007 by the American Geophysical Union.
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