In situ Raman-based measurements of high dissolved methane concentrations in hydrate-rich ocean sediments

70Citations
Citations of this article
54Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

Ocean sediment dissolved CH 4 concentrations are of interest for possible climate-driven venting from sea floor hydrate decomposition, for supporting the large-scale microbial anaerobic oxidation of CH 4 that holds the oceanic CH 4 budget in balance, and for environmental issues of the oil and gas industry. Analyses of CH 4 from recovered cores near vent locations typically show a maximum of ∼1 mM, close to the 1 atmosphere equilibrium value. We show from novel in situ measurement with a Raman-based probe that geochemically coherent profiles of dissolved CH 4 occur rising to 30 mM (pCH 4 = 3 MPa) or an excess pressure ∼3× greater than CO 2 in a bottle of champagne. Normalization of the CH 4 Raman 1 peak to the ubiquitous water 2 bending peak provides a fundamental internal calibration. Very large losses of CH 4 and fractions of other gases (CO 2, H 2 S) must typically occur from recovered cores at gas rich sites. The new data are consistent with observations of microbial biomass and observed CH 4 oxidation rates at hydrate rich sites and support estimates of a greatly expanded near surface oceanic pore water CH 4 reservoir. Copyright 2011 by the American Geophysical Union.

Cite

CITATION STYLE

APA

Zhang, X., Hester, K. C., Ussler, W., Walz, P. M., Peltzer, E. T., & Brewer, P. G. (2011). In situ Raman-based measurements of high dissolved methane concentrations in hydrate-rich ocean sediments. Geophysical Research Letters, 38(8). https://doi.org/10.1029/2011GL047141

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free