Environmental Geology

, Volume 46, Issue 8, pp 997–1002 | Cite as

A new estimate of global methane flux from onshore and shallow submarine mud volcanoes to the atmosphere

  • Giuseppe EtiopeEmail author
  • Alexei V. Milkov
Original Article


A new estimate of global methane emission into the atmosphere from mud volcanoes (MVs) on land and shallow seafloor is presented. The estimate, considered a lower limit, is based on 1) new direct measurements of flux, including both venting of methane and diffuse microseepage around craters and vents, and 2) a classification of MV sizes in terms of area (km2) based on a compilation of data from 120 MVs. The methane flux to the atmosphere is conservatively estimated between 6 and 9 Mt y−1. This emission from MVs is 3–6% of the natural methane sources and is comparable with ocean and hydrate sources, officially considered in the atmospheric methane budget. The total geologic source, including MVs, seepage from seafloor, microseepage in hydrocarbon-prone areas and geothermal sources, would amount to 35–45 Mt y−1. The authors believe it is time to add this parameter in the Intergovernmental Panel on Climate Change official tables of atmospheric methane sources.


Methane Mud volcanoes Greenhouse gas Climate change 



This work is a contribution of the CCD-7 Working-Group (Internal Carbon) of the INQUA Carbon Commission. Thanks are due to A. Feizullayev and A. Solecki for providing useful information on MVs of Azerbaijan and Ukraine, and to P. Favali for valuable discussions and support. Tha authors also thank A. Judd and an anonymous reviewer for their helpful comments.


  1. Aslan A, Warne AG, White WA, Guevara EH, Smyth RC, Raney JA, Gibeaut JC (2001) Mud volcanoes of the Orinoco Delta, Eastern Venezuela. Geomorphology, 41:323–336Google Scholar
  2. Crutzen PJ (1991) Methane’s sinks and sources. Nature, 350:380–381Google Scholar
  3. Dadashev FG (1963) Hydrocarbon gases of mud volcanoes of Azerbaijan. Azerneshr, Baku (in Russian)Google Scholar
  4. Delisle G, Von Rad U, Andruleit H, Von Daniels CH, Tabrez AR, Inam A (2002) Active mud volcanoes on- and offshore eastern Makran, Pakistan. Int.J.Earth Sci., 91:93–110Google Scholar
  5. Dia AN, Castrec M, Boulegue J, Comeau P (1999). Trinidad mud volcanoes: where do the expelled fluids come from? Geochim. Cosm. Acta, 63, 7/8:1023–1038Google Scholar
  6. Dimitrov L (2002) Mud volcanoes—the most important pathway for degassing deeply buried sediments. Earth-Sci. Rev., 59:49–76Google Scholar
  7. Dimitrov L (2003) Mud volcanoes—a significant source of atmospheric methane. Geo-Mar. Lett., doi: 10.1007/s00367–003–0140–3Google Scholar
  8. Etiope G, Caracausi A, Favara R, Italiano F, Baciu C (2002) Methane emission from the mud volcanoes of Sicily (Italy). Geoph. Res. Lett., 29, 8, 10.1029/2001GL014340Google Scholar
  9. Etiope G, Caracausi A, Favara R, Italiano F, Baciu C (2003) Reply to comment by A. Kopf on “Methane emission from the mud volcanoes of Sicily (Italy)”, and notice on CH4 flux data from European mud volcanoes. Geoph. Res. Lett., 30, 2, 1094, 10.1029/2002GL016287Google Scholar
  10. Etiope G, Baciu C, Caracausi A, Italiano F, Cosma C (2004) Gas flux to the atmosphere from mud volcanoes in Eastern Romania. Terra Nova (in press)Google Scholar
  11. Etiope G, Klusman RW (2002) Geologic emissions of methane into the atmosphere. Chemosphere, 49:777–789Google Scholar
  12. Guliyev IS (1992) A review of mud volcanism. Azerbaijan Academy of Sciences, Institute of Geology, Azerbaijan, 65 ppGoogle Scholar
  13. Guliyev IS, Feizullayev AA (1997) All about mud volcanoes. Baku Pub.House, NAFTA-Press, 120 ppGoogle Scholar
  14. Gurieva ZI, Sharkov VV (1987) The study of mud volcanoes on Sakhalin Island based on aerophoto data. Pacific Ocean Geology (Tihookeanskaya Geologiya), 4:58–65 (in Russian)Google Scholar
  15. Henry P, Le Pichon X, Lallemant S, Lance S, Martin JB, Foucher J-P, Fiala-Medioni A, Rostek F, Guilhaumou N, Pranal V, Castrec M (1996) Fluid flow in and around and volcano field seaward of the Barbados accretionary wedge: results from Manon cruise. J Geoph Res 101:20297–20323CrossRefGoogle Scholar
  16. Holland CW, Etiope G, Milkov AV, Michelozzi E, Favali P (2003) Mud volcanos discovered offshore Sicily. Marine Geology, 199:1–6Google Scholar
  17. Hovland M, Curzi PV (1989) Gas seepage and assumed mud-diapirism in the Italian central Adriatic sea. Mar Pet Geol 6:161–169CrossRefGoogle Scholar
  18. Humphrey WE (1963) Sedimentary volcanism in eastern Mexico and northern Colombia. Geol.Soc.Am.Bull., 74:125–128Google Scholar
  19. Intergovernmental Panel on Climate Change (2001) In: Houghton JT, Ding Y, Griggs DJ, Noguer M, van der Linden PJ, Dai X, Maskell K, Johnson CA (Eds), Climate Change 2001: The scientific basis. Cambridge Univ PressCambridge, UK, 881 ppGoogle Scholar
  20. Jakubov AA, Alizade AA, Zeinalov MM (1971) Mud volcanoes of Azerbaijan SSR, Atlas, Elm, Baku, pp.257 (in Russian)Google Scholar
  21. Judd AG, Hovland M, Dimitrov LI, Garcia Gil S, Jukes V (2002). The geological methane budget at Continental Margins and its influence on climate change. Geofluids, 2:109–126Google Scholar
  22. Kopf AJ (2002) Significance of mud volcanism. Rev. Geophysics, 40(2):1005, doi: 10.1029/2000RG000093Google Scholar
  23. Kopf AJ (2003) Global methane emisssion through mud volcanoes and its past and present impact on the Earth’s climate. Int.J.Earth Sci., 92:806–816Google Scholar
  24. Kvenvolden KA, Lorenson TD, Reeburgh W (2001) Attention turns to naturally occurring methane seepage. EOS, 82:457Google Scholar
  25. Lacroix AV (1993) Unaccounted-for sources of fossil and isotopically enriched methane and their contribution to the emissions inventory: a review and synthesis. Chemosphere, 26:507–557Google Scholar
  26. Leifer I, Patro RK (2002) The bubble mechanism for methane transport from the shallow sea bed to the surface: A review and sensitivity study: Cont. Shelf Res., 22(16):2409–2428Google Scholar
  27. Lelieveld J, Crutzen PJ, Dentener FJ (1998) Changing concentration, lifetime and climate forcing of atmospheric methane. Tellus, 50B:128–150Google Scholar
  28. Martinelli G (1999) Mud volcanoes of Italy: a review. Giornale di Geologia, 61:107–113Google Scholar
  29. Milkov AV (2000) Worldwide distribution of submarine mud volcanoes and associated gas hydrates. Marine Geology, 167(1–2):29–42Google Scholar
  30. Milkov AV, Sassen R, Apanasovich TV, Dadashev FG (2003) Global gas flux from mud volcanoes: a significant source of fossil methane in the atmosphere and the ocean. Geoph. Res. Lett., 30(2):1037, doi:10.1029/2002GL016358Google Scholar
  31. Reed DL, Silver EA, Tagudin JE, Shipley TH, Vrolijk P (1990) Relations between mud volcanoes, thrust deformation, slope sedimentation, and gas hydrate, offshore north Panama. Mar.Pet. Geol., 7:44–54Google Scholar
  32. Revil A (2002) Genesis of mud volcanoes in sedimentary basins: a solitary wave-based mechanism. Geoph.Res. Lett., 29, 12:10.1029/2001GL014465Google Scholar
  33. Yin P, Berné S, Vagner P, Loubrieu B, Liu Z (2003) Mud volcanoes at the shelf margin of the East China Sea. Mar. Geology, 194:135–149Google Scholar

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  1. 1.INGVIstituto Nazionale di Geofisica e VulcanologiaRomeItaly
  2. 2.Exploration and Production TechnologyBP AmericaHoustonUSA

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