20. Determination of In Situ Methane Based on Analysis of Void Gas1

Arthur J. Spivack,2 Craig McNeil,2 Nils G. Holm,3 and Kai-Uwe Hinrichs4


A method for quantifying in situ dissolved methane concentrations in sediment cores that have gas voids is described. The method relies on normalizing methane (CH4) in the gas voids to nitrogen (N2) and/or argon (Ar). The principles of the method are presented. The method was tested during Ocean Drilling Program Leg 201, and preliminary results indicate that it can be used to generate reproducible and accurate dissolved methane values if argon and nitrogen are both measured or if one is measured along with pressure of the gas void.

1Spivack, A.J., McNeil, C., Holm, N.G., and Hinrichs, K.-U., 2006. Determination of in situ methane based on analysis of void gas. In Jørgensen, B.B., D'Hondt, S.L., and Miller, D.J. (Eds.), Proc. ODP, Sci. Results, 201 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/201_SR/119/119.htm>. [Cited YYYY-MM-DD]

2NASA Astrobiology Institute, Graduate School of Oceanography, University of Rhode Island, Narragansett RI 02882, USA. spivack@gso.uri.edu

3Department of Geology and Geochemistry, Stockholm University, 10691 Stockholm, Sweden.

4DFG-Research Center Ocean Margins, Department of Geosciences, University of Bremen, P.O. Box 330440, 28334 Bremen, Germany.

Initial receipt: 18 January 2005
Acceptance: 1 February 2006
Web publication: 10 July 2006
Ms 201SR-119