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.

Uncertainty is ±33% from the calculated mean. Sediment depth is given in mbsf.

Supplement to: Spivack, Arthur J; McNeil, Craig; Holm, Nils G; Hinrichs, Kai-Uwe (2006): Determination of in situ methane based on analysis of void gas. In: Jørgensen, BB; D'Hondt, SL; Miller, DJ (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 201, 1-11