ESTIMATION OF METHANE FLUX FROM BOTTOM SEDIMENTS TO WATER AS A RESULT OF METHANE HYDRATE DEGRADATION CAUSED BY WATER WARMING IN THE STRAIT OF TARTARY

B.A. Burov, V.A. Luchin, A.I. Obzhirov and A.A. Karnaukhov

Il′ichev Pacific Oceanologic Institute, Far East Branch, Russian Academy of Sciences, ul. Baltiiskaya 43, Vladivostok, 690041 Russia e-mail: burov@poi.dvo.ru

The paper presents estimates of methane fluxes emanated to water because of methane hydrate dissociation induced by the trend to water warming in the Strait of Tartary. These estimates are based on the measured depth of methane hydrate occurrence in sediments, hydrological measurements made just after the cores with methane hydrates were lifted up, and calculated trends to water temperature variation in a number of water horizons in the Strait of Tartary, where methane hydrates were found. It is shown that methane, which is produced by the methane hydrate degradation, is the main source of anomaly high methane concentrations in water column and methane fluxes to the atmosphere in this region. The source of the methane ecological hazard in the eastern region of the Strait of Tartary is localized in the narrow band of bottom sediments within the depth interval of 300–330 m extending for about of 150 km in the longitudinal direction. The methane flux from the bottom sediments to the water layer in this zone is about 0.17 mol/m2day. The response of methane hydrate to sea water warming may be described as the thickness of sediment layer with dissociated methane hydrates which corresponding to 0.1 °C water temperature growth. In the Strait of Tartary area under research this characteristic has a value between 1.5 and 1.8 м/0.1 °C.

Key words: methane hydrate stability zone; conditions of methane hydrate growth and dissociation; trend of sea water warming; heat flux.

REFERENCES

1. Gidrometeorologiya i gidrokhimiya morei. [Hydro-meteorology and hydrochemistry of seas. Vol. 8. Japan sea. Issue 1. Hydrochemical conditions]. Vasilev A.S., Terziev F.S., Kosarev A.N., Eds., St. Petersburg, Gidrometeoizdat Publ., 2003. 398 p. (in Russian).

2. Zharov, A.E., Kirillova, G.L., Margulis, L.S., et al. Geolog iya, geodinamika i perspektivy neftegazonosnosti osadochnykh basseinov Tatarskogo proliva. [Geology, geodynamics and perspectives in oil and gas potential of the Strait of Tartary sedimentary basins]. Vladivostok, Dalnauka Publ., 2004. 220 p. (in Russian).

3. Lein, A. Yu., Ivanov, M.V. Biogeokhimicheskii tsykl metana v okeane. [Biogeochemical cycle of methane in the Ocean]. Moscow, Nauka Publ., 2009. 576 p. (in Russian).

4. Luchin, V.A. Seasonal water temperature variability in an active layer of Far Eastern seas. Dal’nevostochnye morya Rossii. Kn. 1. Okeanologicheskie issledovaniya (Far Eastern Seas of Russia. Book 1. Oceanological Studies), Akulichev, V.A., et al., Eds., Moscow, Nauka Publ., 2007, pp. 232–252. (in Russian).

5. Mishukova, G.I., Mishukov, V.F., Obzhirov, A.I., Pestrikova, N.L., Vereshchagina, O.F. Peculiarities of the distribution of methane concentration and methane fluxes at the water-air interface in the Strait of Tartary of the Sea of Japan. Meteorologiya i Gidrologiya. [Meteorology and Hydrology]. 2015, vol. 6, pp. 89–96. (in Russian).

6. Sergienko, V.I., Lobkovskiy, L.I., Semiletov, I.P., Dudarev, O.V., et al. Underwater permafrost degradation and dissociation of gas hydrates on the shelf of eastern Arctic seas as a possible reason of “methane catastrophe”: some results of complex investigations in 2011. Doklady Akademii Nauk, 2012, vol. 446, no. 3, pp. 330–335. (in Russian).

7. Yarichin, V.G. Some features of horizontal water motion in the Sea of Japan to the north of 40° N, Tr. DVNII, 1982, no. 96, pp. 111–120. (in Russian).

8. Dickens, G. R., Quinby-Hunt, M.S. Methane hydrate stability in sea-water. Geophys. Res. Lett., 1994, no. 21, pp. 2115–2118.

9. Ed Dlugokencky. NOAA/ESRL //www.esrl.noaa.gov/ gmd/ccgg/trends_ch4/

10. Ferre, B., Mienert, J., and Feseker, T. Ocean temperature variability for the past 60 years оn the Norwegian-Svalbard margin influences gashydrate stability on human time scales. J. Geoph. Res., 2012, vol. 117. C10017. DOI: 10.1029/2012JC008300.

11. Itoh, M. Warming of intermediate water in the Sea of Okhotsk since the 1950s. J. of Oceanography, 2007, vol. 63, pp. 637–641.

12. Jin, Y.K., Minami, H., Baranov, B., Obzhirov, A. Operation report of Sakhalin slope gas hydrate project II, 2014, R/V Akademik M.A. Lavrentyev Cruise 67, KOPRI Incheon, 2015, 121 p.

13. Kannberg, P.K., Trehu, A.M., Pierce, S.D., Paull, C.K., Caress, D.W. Temporal variation of methane flares in theocean above Hydrate Ridge, Oregon. Earth and Planetary Science Letters, 2013, vol. 368, pp. 33–42.

14. Kwon, Y.-O., Kim K., Kim Y.-G., and Kim K.-R. Diagnosing long-term trends of the water mass properties in the East Sea (Sea of Japan). Geophys. Res. Lett., 2004. 31, L20306, DOI:10.1029/2004GL020881.

15. Lee, M.W., and Collett, T.S. Gas hydrate and free gas saturations estimated from velocity logs on Hydrate Ridge, offshore Oregon, USA. In Tréhu, A.M., Bohrmann, G., Torres, M.E., and Colwell, F.S. (Eds.), Proc. ODP, Sci. Results, 204: College Station, TX (Ocean Drilling Program), 2006, pp. 1–25. DOI:10.2973/ odp.proc.sr.204.103.2006.

16. Levitus, S., Antonov, J., Boyer, T.P. Warming of the world ocean, 1955–2003. Geophys. Res. Lett., 2005/ 32, L02604. DOI:10.1029/2004GL021592.

17. Luchin, V., Kruts A., Sokolov, O., et al. Climatic Atlas of the North Pacific Seas 2009: Bering Sea, Sea of Okhotsk, and Sea of Japan. V. Akulichev, Yu. Volkov, V. Sapozhnikov, S. Levitus, (Eds.), NOAA Atlas NESDIS67. U.S. Gov. Printing Office, Wash. D.C., 329 pp., CD- Disc.

18. Mascarelli A.L. A sleeping giant? Nat. Rep. Clim. Change, 2009, no. 3, pp. 46–49. DOI:10.1038/climate.2009.24.

19. Milkov, A.V., Sassen R., Novikova I., Mikhailov E. Gas hydrates at minimum stability water depths in the Gulf of Mexico: significance to geohazard assessment. Gulf Coast Association of Geological Societies Transactions, 2000, vol. L, pp. 217–224.

20. Nakanowatari, T., Ohshima K.I., and Wakats uchi M. Warming and oxygen decrease of intermediate water in the northwestern North Pacific, originating from the Sea of Okhotsk, 1955–2004. Geophys. Res. Lett., 2007, no. 34. L04602. DOI: 10.1029/2006GL028243.

21. Reagan, M.T., Moridis, G.J. Dynamic response of oceanic hydrate deposits to ocean temperature change. J. Geoph. Res., 2008, vol. 113. C12023. DOI:10.1029/2008JC004938.

22. Shoji, H., Jin, Y. K., Baranov, B., Nikolaeva, N. and Obzhirov, A. Operation report of Sakhalin slope gas hydrate Project II, 2013, R/V Akademic M.A. Lavren-tyev Cruise 62, June 19–July 6, 2013. Eds. H. Shoji, Y.K. Jin, B. Baranov, N. Nikolaeva and A. Obzhirov. Published by Environmental and Energy Resources Research Center, Kitami Institute of Technology, Feb. 2014.

23. Thatcher, K.E., Westbrook, G.K., Sarkar, S., and Minshull, T.A. Methane release from warming-induced hydrate dissociation in the West Svalbard continental margin: Timing, rates, and geological controls. J. Geophys. Res. Solid Earth, 2013, vol. 118, pp. 22–38.

24. Torres, M.E., McManus, J., Hammond, D.E., et al. Fluid and chemical fluxes in and out of sediments hosting methane hydrate deposits on Hydrate Ridge, OR, I: hydrologic provinces. Earth Planet. Sci. Lett. 2002, vol. 201, pp. 525–540.

25. Xu, W., Lowel, R., Peltzer, E.T. Effect of sea floor temperature and pressure variations on methane flux from a gas hydrate layer: comparison between current and late Paleocene climate conditions. J. Geophys. Res., 2001, vol. 106, N B1, pp. 26413–26423.