Abstract
Methane emissions from the sea floor affect methane inputs into the atmosphere1, ocean acidification and de-oxygenation2,3, the distribution of chemosynthetic communities and energy resources. Global methane flux from seabed cold seeps has only been estimated for continental shelves4, at 8 to 65 Tg CH4 yrâ1, yet other parts of marine continental margins are also emitting methane. The US Atlantic margin has not been considered an area of widespread seepage, with only three methane seeps recognized seaward of the shelf break. However, massive upper-slope seepage related to gas hydrate degradation has been predicted for the southern part of this margin5, even though this process has previously only been recognized in the Arctic2,6,7. Here we use multibeam water-column backscatter data that cover 94,000 km2 of sea floor to identify about 570 gas plumes at water depths between 50 and 1,700 m between Cape Hatteras and Georges Bank on the northern US Atlantic passive margin. About 440 seeps originate at water depths that bracket the updip limit for methane hydrate stability. Contemporary upper-slope seepage there may be triggered by ongoing warming of intermediate waters, but authigenic carbonates observed imply that emissions have continued for more than 1,000 years at some seeps. Extrapolating the upper-slope seep density on this margin to the global passive margin system, we suggest that tens of thousands of seeps could be discoverable.
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References
McGinnis, D. F., Greinert, J., Artemov, Y., Beaubien, S. E. & Wuest, A. Fate of rising methane bubbles in stratified waters: How much methane reaches the atmosphere? J. Geophys. Res. 111, C09007 (2006).
Biastoch, A. et al. Rising Arctic Ocean temperatures cause gas hydrate destabilization and ocean acidification. Geophys. Res. Lett. 38, L08602 (2011).
Archer, D., Buffett, B. & Brovkin, V. Ocean methane hydrates as a slow tipping point in the global carbon cycle. Proc. Natl Acad. Sci. USA 106, 20596â20601 (2009).
Hovland, M., Judd, A. G. & Burke, R. A. Jr The global flux of methane from shallow submarine sediments. Chemosphere 26, 559â578 (1993).
Phrampus, B. J. & Hornbach, M. J. Recent changes to the Gulf Stream causing widespread gas hydrate destabilization. Nature 490, 527â530 (2012).
Berndt, C. et al. Temporal constraints on hydrate-controlled methane seepage off Svalbard. Science 343, 284â287 (2014).
Westbrook, G. K. et al. Escape of methane gas from the seabed along the West Spitsbergen continental margin. Geophys. Res. Lett. 36, L15608 (2009).
Brothers, L. L. et al. Evidence for extensive methane venting on the southeastern US Atlantic margin. Geology 41, 807â810 (2013).
Demopoulos, A. W., Bourque, J. R., Brooke, S. & Ross, S. W. Benthic Community Structure at Newly Investigated Hydrocarbon Seeps on the Continental Slope of the Western North Atlantic (Ocean Sciences Meeting, 2014).
Reeburgh, W. S. Oceanic methane biogeochemistry. Chem. Rev. 107, 486â513 (2007).
Bayon, G., Henderson, G. M. & Bohn, M. UâTh stratigraphy of a cold seep carbonate crust. Chem. Geol. 260, 47â56 (2009).
Austin, J. A., Christie-Blick, N., Malone, M. & Party, S. S. Proc. Ocean Drilling Program, Initial Reports Vol. 174A (Ocean Drilling Program, 1998)
Scranton, M. I., Guida, V., Gong, D., Kessler, J. & Rona, P. Methane Venting in the Hudson Canyon: Hydrate Destabilization or Something Else? (Ocean Sciences Meeting, 2012).
Newman, K. R. et al. Active methane venting observed at giant pockmarks along the US mid-Atlantic shelf break. Earth Planet. Sci. Lett. 267, 341â352 (2008).
Frye, M., Shedd, W. & Schuenemeyer, J. Gas Hydrate Resource Assessment Atlantic Outer Continental Shelf RED 2013-1 49 (BOEM, 2013); available at www.boem.gov/BOEM-Report-RED/
Poag, C. W. Stratigraphy of the Atlantic continental shelf and slope of the United States. Annu. Rev. Earth Planet. Sci. 6, 251â280 (1978).
Brothers, D. S. et al. Seabed fluid expulsion along upper slope and outer shelf of the US Atlantic continental margin. Geophys. Res. Lett. 41, 96â101 (2014).
Ruppel, C. Methane hydrates and contemporary climate change. Nature Educ. Knowl. 3, 29 (2011); available at www.nature.com/scitable/knowledge/library/methane-hydrates-and-contemporary-climate-change-24314790
Hovland, M., Gardner, J. V. & Judd, A. G. The significance of pockmarks to understanding fluid flow processes and geohazards. Geofluids 2, 127â136 (2002).
Gawarkiewicz, G. G., Todd, R. E., Plueddemann, A. J., Andres, M. & Manning, J. P. Direct interaction between the Gulf Stream and the shelfbreak south of New England. Sci. Rep. 2, 553 (2012).
Greene, C. H. & Pershing, A. J. The flip-side of the North Atlantic Oscillation and modal shifts in slope-water circulation patterns. Limnol. Oceanogr. 48, 319â322 (2003).
Benway, R. L. Water Column Thermal Structure Across the Shelf and Slope Southeast of Sandy Hook, New Jersey in 1985 Report No. N1196, 6 (Northwest Atlantic Fisheries Organization, 1986)
Hornbach, M. J., Ruppel, C. & Van Dover, C. L. Three-dimensional structure of fluid conduits sustaining an active deep marine cold seep. Geophys. Res. Lett. 34, L05601 (2007).
Person, M. et al. Pleistocene hydrogeology of the Atlantic continental shelf, New England. Geol. Soc. Am. Bull. 115, 1324â1343 (2003).
Cohen, D. et al. Origin and extent of fresh paleowaters on the Atlantic Continental Shelf, USA. Ground Water 48, 143â158 (2010).
Römer, M., Sahling, H., Pape, T., Bohrmann, G. & SpieÃ, V. Quantification of gas bubble emissions from submarine hydrocarbon seeps at the Makran continental margin (offshore Pakistan). J. Geophys. Res. 117, C10015 (2012).
Weber, T. C. et al. Acoustic estimates of methane gas flux from the seabed in a 6000 km2 region in the Northern Gulf of Mexico. Geochem. Geophys. Geosyst. 15, 1911â1925 (2014).
Kessler, J. D. et al. A persistent oxygen anomaly reveals the fate of spilled methane in the deep Gulf of Mexico. Science 331, 312â315 (2011).
Sychev, V. V. et al. Thermodynamic Properties of Methane (Hemisphere Publishing, 1987).
Sloan, E. D. Jr Clathrate Hydrates of Natural Gases 2nd edn (Marcel Dekker Inc., 1998).
Acknowledgements
The National Oceanographic and Atmospheric Administration (NOAA) Office of Ocean Exploration and Research funded the 2012/2013 Atlantic canyons mapping project and managed the acquisition of the data used in this study with the vessel Okeanos Explorer and ROV Deep Discoverer. C. Van Dover analysed the length scales for Fig. 2. W. Waite, A. Demopoulos, L. Brothers and J. Chaytor provided advice and comments. C.R. had support from US Department of Energy-USGS interagency agreement DE-FE0006781. M.K. was financially supported by a NOAA Hollings Scholarship in summer 2013. Fledermaus Mid-Water software for A.S. and M.K. was provided by QPS. Mention of trade names does not imply US Government endorsement of commercial products.
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A.S. collected some of the multibeam data, devised the approach for analysis of the water-column anomalies, conducted the second full analysis of the plumes, completed the cluster analysis and prepared the plume database. C.R. wrote the paper, prepared most of the figures, and performed the video analysis and flux calculations. M.K. completed the first full analysis of the backscatter data set. D.B. contributed the pockmark database and assisted with geologic interpretations and map preparation. E.L. collected some of the multibeam data and analysed the episodicity of some seeps using repeat multibeam data sets.
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Skarke, A., Ruppel, C., Kodis, M. et al. Widespread methane leakage from the sea floor on the northern US Atlantic margin. Nature Geosci 7, 657â661 (2014). https://doi.org/10.1038/ngeo2232
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DOI: https://doi.org/10.1038/ngeo2232
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