|Assessing the Response of Methane Hydrates to Environmental Change at the Svalbad Continental Margin
||Last Reviewed 1/5/2015
The goal of this project is to study the biogeochemical response of the gas hydrate system on the Svalbard margin to environmental change.
Oregon State University, Corvallis, OR 97339-1086
Many questions must be answered in order to understand the role gas hydrates play in the global carbon cycle and their potential as a future energy resource. More research is needed to determine:
- The residence time of gas hydrates near the seafloor and deeper within the sediment column
- The sources and pathways of methane transport
- The nature and driving mechanisms for flow
- The changes in the (above) variables over time
Characterizing carbon cycling in the critical zone on the upper continental slope will increase our knowledge of the hydrate stability transition at/near the seafloor. The upper edge of gas hydrate stability defines one of the most climate-sensitive boundaries and represents a potential “window” to fluid and gas migration from below the seaward-deepening bottom simulating reflector. Hydrate transformations can be documented through analyses of geochemical data, modeling efforts to quantify each process and its associated rate, and obtaining ground truth data of these geochemically-derived inferences through analyses of microbial communities.
German and Norwegian colleagues are focusing on characterizing gas hydrate abundance, distribution, and the effect of environmental changes on gas hydrate stability at the western Spitsbergen continental margin. Oregon State researchers will explore the role of biogeochemical processes in the region via pore water and sediment geochemical analyses, microbiological analyses, and kinetic modeling. The roles of microbial methane generation and oxidation will be constrained at and below the sulfate-methane transition zone, enabling researchers to quantify the amount of methane as it escapes, moves, or is consumed. These fundamental data are needed in order to constrain models for assessing the residence time of carbon in various methane-rich reservoirs as well as the dynamic response of these systems to environmental change and the resulting effect in the overlying water column. The proposed research has the potential to increase our understanding of the response and impact of gas hydrates to changing environmental conditions.
Researchers participated in two research cruises at the edge of the gas hydrate stability field where they collaborated with Norwegian scientists to collect samples offshore Svalbard for geochemical and microbiological analyses. In addition, researchers participated in another DOE-funded cruise to the Cascadia margin, where they collected additional samples for microbiological analyses, which will complement the principal investigator’s geochemistry data. Modelling is underway and a comparative study using the various available codes to calculate gas hydrate stability was presented at a gas conference in Taiwan in September 2014.
Current Status (January 2015)
Geochemical and microbiological samples are being analyzed. Samples from Cascadia are being analyzed to establish procedures that will be applied to the Svalbard samples. Researchers continue to test and improve methane measurement techniques using the Los Gatos instruments. Concentration measurements are now very routine and highly accurate. Isotope analyses have not yet been fully implemented because their analytical precision and accuracy needs to be improved.
Project Start: 11/01/2013
Project End: 10/31/2015
DOE Contribution: $645,724
Performer Contribution: $180,000
NETL – Joseph Renk (Joseph.Renk@netl.doe.gov or 412-386-6406)
Oregon State University – Marta Torres (firstname.lastname@example.org or 541-737-2901)