A large methane plume east of Bear Island (Barents Sea): implications for the marine methane cycle

Abstract

A pockmark field extending over 35 km2 at 74°54′N, 27°3′E, described by Solheim and Elverhøi (1993), was re-surveyed and found to be covered with more than 30 steep-sided craters between 300 and 700 m in diameter and up to 28 m deep. The craters are thought to have been formed by an explosive gas eruption. Anomalously high concentrations of methane in the shelf waters around the craters suggest that a strong methane source near this area is still active today. Methane enrichment more than 10 km away from the crater field indicates the large dimensions of a plume and the amount of gas released from sources below the seafloor of the Barents Sea shelf. From the characteristic vertical decrease of methane towards the sea surface, it is concluded that biota are extensively using this energy pool and reducing the methane concentration within the water column by about 98% between 300 m depth and the sea surface. Degassing to the atmosphere is minimal based on the shape of the methane concentration gradient. Nevertheless, the net flux of methane from this area of the Barents Sea is about 2.9 × 104 g CH4 km−2 yr−1 and thus in the upper range of the presently estimated global marine methane release. This flux is a minimum estimate and is likely to increase seasonally when rough weather leads to more effective vertical mixing during autumn and winter. The amount of methane consumed in the water column, however, is about 50 times greater and hence should significantly contribute to the marine carbon inventory.

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References

  1. Andreassen K, Hogstad K, Berteusen KA (1990) Gas hydrate in the southern Barents Sea, indicated by a shallow seismic anomaly. First Break 8:235–245

    Google Scholar 

  2. Antonsen P, Elverhøi A, Dypvik H, Solheim A (1991) Shallow bedrock geology of the Olga Basin area, northwestern Barents Sea. AAPG Bull 75:1178–1194

    Google Scholar 

  3. Baker ET, Massoth GJ, Feeley RA (1987) Cataclysmic hydrothermal venting on the Juan de Fuca Ridge. Nature 329:149–151

    Google Scholar 

  4. Blake DR, Rowland FS (1988) Continuing worldwide increase in tropospheric methane. Science 239:1129–1131

    Google Scholar 

  5. Cicerone RJ, Oremland R (1988) Biogeochemical aspects of atmospheric methane. Global Biogeochemical Cycles 2:299–327

    Google Scholar 

  6. Conrad R, Seiler W (1988) Methane and hydrogen in seawater (Atlantic Ocean). Deep-Sea Res 35:1903–1917

    Google Scholar 

  7. Elverhøi A, Antonsen P, Flood SB, Solheim A, Vullstad AA (1988) The physical environment, western Barents Sea 1:1500000, shallow bedrock geology. Norsk Polarinst Skrif 179:32 pp

    Google Scholar 

  8. Faber E, Stahl W (1983) Analytic procedure and results of an isotope geochemical surface survey in an area of the British North Sea. In: Brooks J (ed) Petroleum Geochemistry and Exploration in Europe. Blackwell Scientific, Oxford, pp 51–63

    Google Scholar 

  9. Hovland M (1984) Gas-induced erosion features in the North Sea. Earth Surf Process Landforms 9:209–228

    Google Scholar 

  10. Hovland M (1991) Large pockmarks, gas-charged sediments and possible clay diapirs in the Skagerrak. Mar Petrol Geol 8:311–316

    Google Scholar 

  11. Hovland M, Judd AG (1988) Seabed Pockmarks and Seepages, Impact on Geology, Biology and the Marine Environment. Graham and Trotman, London

    Google Scholar 

  12. Hovland M, Judd AG, Burke Jr RA (1993) The global flux of methane from shallow submarine sediments. Chemosphere 26:559–578

    Google Scholar 

  13. Lang PM, Steele LP, Martin RC (1992) Atmospheric Methane Mixing Ratios: Cooperative Flask Sampling Network, 1983–1991. National Oceanic and Atmospheric Administration (NOAA), Climate Monitoring and Diagnostics Laboratory (CMDL), Boulder

    Google Scholar 

  14. Lammers S (1994) Methane cycling in the marine environment. Dissertation, Univ Kiel

  15. Lammers S, Suess E (1994) An improved head-space analysis method for methane in seawater. Mar Chem 47:115–125

    Google Scholar 

  16. Løvø V, Elverhøi A, Antonsen P, Solheim A, Butenko G, Gregersen O, Liestøl O (1990) Submarine permafrost and gas hydrates in the northern Barents Sea. Norsk Polarinst Rapp 56:171 pp

  17. Rasmussen RA, Khalil MAK (1981a) Atmospheric methane (CH4): trends and seasonal cycles. J Geophys Res 86:9826–9832

    Google Scholar 

  18. Rasmussen RA, Khalil MAK (1981b) Increase in the concentration of atmospheric methane. Atmos Environ 15:883–886

    Google Scholar 

  19. Schmitt M, Faber E, Botz R, Stoffers P (1991) Extraction of methane from seawater using ultrasonic vacuum degassing. Anal Chem 63:529–531

    Google Scholar 

  20. Scranton M, Brewer PG (1978) Consumption of dissolved methane in the deep ocean. Limnol Oceanogr 23:1207–1213

    Google Scholar 

  21. Solheim A, Elverhøi A (1985) A pockmark field in the central Barents Sea; gas from petrogenic source? Polar Res 3:11–19

    Google Scholar 

  22. Solheim A, Elverhøi A (1993) Gas related sea-floor craters in the Barents Sea. Geo-Mar Lett 13:235–243

    Google Scholar 

  23. Solheim A, Russwurm L, Elverhøi A, Nyland-Berg M (1991) Glacial geomorphic features in the northern Barents Sea: direct evidence for grounded ice and implications for the pattern of deglaciation and late glacial sedimentation. In: Dowdeswell JA, Scourse JD (eds) Glacimarine Environments: Processes and Sediments. Spec Publ Geol Soc London 53:253–268

  24. Steele LP, Dlugokencky EJ, Lang PM, Tans PP, Martin RC, Masarie KA (1992) Slowing down of the global accumulation of atmospheric methane during the 1980s. Nature 358:313–316

    Google Scholar 

  25. Swift JH (1986) The arctic waters. In: Hurdle BG (ed) The Nordic Seas. Springer, New York, pp 129–153

    Google Scholar 

  26. Wanninkhof R (1992) Relationship between wind speed and gas exchange over the ocean. J Geophys Res 97:7373–7382

    Google Scholar 

  27. Ward BB, Kilpatrick KA (1992) Methane oxidation associated with mid-depth methane maxima in the Southern California Bight. Cont Shelf Res 13:1111–1122

    Google Scholar 

  28. Ward BB, Kilpatrick KA, Novelli PC, Scranton M (1987) Methane oxidation and methane fluxes in the ocean surface layer and deep anoxic waters. Nature 327:226–229

    Google Scholar 

  29. Wiesenburg DA, Guinasso NL (1979) Equilibrium solubilities of methane, carbon monoxide and hydrogen in water and seawater. J Chem Engin Data 24:356–360

    Google Scholar 

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Lammers, S., Suess, E. & Hovland, M. A large methane plume east of Bear Island (Barents Sea): implications for the marine methane cycle. Geol Rundsch 84, 59–66 (1995). https://doi.org/10.1007/BF00192242

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Key words

  • Methane plumes
  • Marine methane cycle
  • Pockmarks
  • Barents Sea