Seasonal variations in the stable carbon isotopic signature of biogenic methane in a coastal sediment
Martens, Christopher S, Blair NE, Green CD, Des Marais DJ. 1986. Seasonal variations in the stable carbon isotopic signature of biogenic methane in a coastal sediment. Science. 233(4770):1300-1303
Systematic seasonal variations in the stable carbon isotopic signature of methan gas occur in the anoxic sediments of Cape Lookout Bight, a lagoonal basin on North Carolina's Outer Banks. Values for the carbon isotope ratio (Delta-13-C) of methan range from -57.3 per mil during summer to -68.5 per mil during winter in gas bubbles with an average methan content of 95%. The variations are hypothesized to result from changes in the pathways of microbial methan production and cycling of key substrates including acetate and hydrogen. The use of stable isotopic signatures to investigate the global methane cycle through mass balance calculations, involving various sediment and soil biogenic sources, appears to require seasonally averaged data from individual sites.
- Type
- Journal Article
- Authors
- Martens, Christopher S; Blair, Neal; Green, Carol; Des Marais, David
- Units
- CALO
- Keywords
- biogenic effects, c 12, C 13, CALO, Cape Lookout Bight, Carbon, Carbon Dioxide, Carteret County, Eastern U.S., Ecology, Gases, Geochemistry, Geology, Hydrocarbons, Isotopes, Marine Sediments, Methane, nearshore environment, North Carolina, Organic Materials, Outer Banks, Seasonal Variations, Sediments, Southeastern U.S., Stable Isotopes