西沙海槽晚更新世冰期以来原地微生物成因水合物储库的变化
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摘要
利用基于热力学理论的CSMHYD程序,计算现今及晚更新世冰期琼东南盆地西沙海槽天然气水合物的稳定带厚度及资源量,讨论晚更新世冰期以来海平面、底水温度和沉积速率变化对西沙海槽天然气水合物储库变化的影响。结果表明:①研究区水深超过600m的海域具备天然气水合物赋存的温压条件。天然气水合物稳定带最大厚度约300 m,位于研究区的中东部和东南部。②晚更新世冰期以来,底水温度的升高抵消了海平面上升对天然气水合物稳定性的影响。研究区冰期和间冰期旋回中沉积速率収生显著变化,沉积速率大的区域,原地微生物成因天然气水合物的浓度也相应较大;导致冰期-间冰期旋回过程中原地微生物成因水合物储库变化的关键因素是甲烷供给及沉积速率,而不是温压条件的变化。③西沙海槽天然气水合物现今的储库比晚更新世冰期的减少了0.78×1012 m3的甲烷气。
Sloan's CSMHYD program was used to calculate the thickness of the gas hydrate stable zone(GHSZ) and the amount of gas hydrate in the Xisha Trough at present and at the last Pleistocene Glaciation, respectively. The effects of the changes in the bottom water temperature and the sea level on GHSZ also discussed. Results showed that the temperature and pressure conditions for gas hydrate formation were available in the Xisha Trough of Qiongdongnan Basin, where water depth is more than 600 m. The thickest GHSZ was located in the east of the study area, with a maximum thickness of more than 300 m. The thickness of GHSZ decreased with the bottom water temperature increase and increased with the sea level increase, wherein the effect of the former was stronger than that of the latter. In the study area, the deposition rate changed significantly during the glacial and interglacial cycles, which changed the concentration of in-situ microbial hydrates. The concentration of methane hydrate formed by in-situ microbial hydrates was also higher in the area with high deposition rate.0.78 × 1012 m3 of methane is released from gas hydrate since the Last Pleistocene Glaciation. The released methane should have greatly affected the environment, such as inducing submarine landslides.
Sloan's CSMHYD program was used to calculate the thickness of the gas hydrate stable zone(GHSZ) and the amount of gas hydrate in the Xisha Trough at present and at the last Pleistocene Glaciation, respectively. The effects of the changes in the bottom water temperature and the sea level on GHSZ also discussed. Results showed that the temperature and pressure conditions for gas hydrate formation were available in the Xisha Trough of Qiongdongnan Basin, where water depth is more than 600 m. The thickest GHSZ was located in the east of the study area, with a maximum thickness of more than 300 m. The thickness of GHSZ decreased with the bottom water temperature increase and increased with the sea level increase, wherein the effect of the former was stronger than that of the latter. In the study area, the deposition rate changed significantly during the glacial and interglacial cycles, which changed the concentration of in-situ microbial hydrates. The concentration of methane hydrate formed by in-situ microbial hydrates was also higher in the area with high deposition rate.0.78 × 1012 m3 of methane is released from gas hydrate since the Last Pleistocene Glaciation. The released methane should have greatly affected the environment, such as inducing submarine landslides.
引文
[1]SLOAN E D.Gas hydrates:review of physical/chemical properties[J].Energy&fuels,1998,12(2):191-196.DOI:10.1021/ef970164+.
[2]于晓果,李家彪.天然气水合物分解及其生态环境效应研究迚展[J].地球科学迚展,2004,19(6):947-954.DOI:10.3321/j.issn:1001-8166.2004.06.012.
[3]陈忠,颜文,陈木宏,等.海底天然气水合物分解与甲烷归宿研究迚展[J].地球科学迚展,2006,21(4):394-400.DOI:10.3321/j.issn:1001-8166.2006.04.008.
[4]MILKOV A V.Global estimates of hydrate-bound gas in marine sediments:how much is really out there?[J].Earth-science reviews,2004,66(3/4):183-197.DOI:10.1016/j.earscirev.2003.11.002.
[5]MéNOT G,BARD E.Geochemical evidence for a large methane release during the last deglaciation from Marmara Sea sediments[J].Geochimica et cosmochimica acta,2010,74(5):1537-1550.DOI:10.1016/j.gca.2009.11.022.
[6]PLAZA-FAVEROLA A,BüNZ S,MIENERT J.Repeated fluid expulsion through sub-seabed chimneys offshore Norway in response to glacial cycles[J].Earth and planetary science letters,2011,305(3/4):297-308.DOI:10.1016/j.epsl.2011.03.001.
[7]KENNETT J P,CANNARIATO K G,HENDY I L,et al.Carbon isotopic evidence for methane hydrate instability during quaternary interstadials[J].Science,2000,288(5463):128-133.DOI:10.1126/science.288.5463.128.
[8]叶黎明,初凤友,葛倩,等.新仙女木末期南海北部天然气水合物分解事件[J].地球科学-中国地质大学学报,2013,38(6):1299-1308.DOI:10.3799/dqkx.2013.127.
[9]WALLMANN K,PINERO E,BURWICZ E,et al.The global inventory of methane hydrate in marine sediments:a theoretical approach[J].Energies,2012,5(7):2449-2498.DOI:10.3390/en5072449.
[10]苏新,陈芳,于兴河,等.南海陆坡中新世以来沉积物特性与气体水合物分布初探[J].现代地质,2005,19(1):1-13.DOI:10.3969/j.issn.1000-8527.2005.01.001.
[11]苏明,杨睿,张翠梅,等.深水沉积体系研究迚展及其对南海北部陆坡区天然气水合物研究的启示[J].海洋地质与第四纪地质,2013,33(3):109-116.
[12]赵广明,叶思源,丁喜桂,等.黄河三角洲全新世以来沉积环境的划分及各环境中碳埋藏速率的评价[J].地球科学-中国地质大学学报,2014,39(4):451-461.DOI:10.3799/dqkx.2014.043.
[13]GUAN J A,LIANG D Q,WU N Y,et al.The methane hydrate formation and the resource estimate resulting from free gas migration in seeping seafloor hydrate stability zone[J].Journal of Asian earth sciences,2009,36(4/5):277-288.DOI:10.1016/j.jseaes.2009.05.008.
[14]TRUNG N N.The gas hydrate potential in the South China Sea[J].Journal of petroleum science and engineering,2012,88-89:41-47.DOI:10.1016/j.petrol.2012.01.007.
[15]王淑红,颜文,宋海斌.末次盛冰期以来西沙海槽天然气水合物储库变化及其对环境的影响[J].地球科学-中国地质大学学报,2008,33(1):74-82.DOI:10.3321/j.issn:1000-2383.2008.01.010.
[16]孙春岩,牛滨华,文鹏飞,等.海上E区天然气水合物地质、地震、地球化学特征综合研究与成藏进景预测[J].地球物理学报,2004,47(6):1076-1085.DOI:10.3321/j.issn:0001-5733.2004.06.021.
[17]苏明,张成,解习农,等.深水峡谷体系控制因素分析-以南海北部琼东南盆地中央峡谷体系为例[J].中国科学:地球科学,2014,44(8):1807-1820.
[18]姚悦,周江羽,雷振宇,等.西沙海槽盆地强限制性中央峡谷水道地震相与内部结构的分段特征[J].沉积学报,2018,36(4):787-795.DOI:10.14027/j.issn.1000-0550.2018.048.
[19]QIN Z L,WU S G,WANG D W,et al.Mass transport deposits and processes in the north slope of the Xisha Trough,northern South China Sea[J].Acta oceanologica sinica,2015,34(9):117-125.DOI:10.1007/s13131-015-0608-9.
[20]CHEN H,XIE X N,ZHANG W Y,et al.Deep-water sedimentary systems and their relationship with bottom currents at the intersection of Xisha Trough and Northwest Sub-Basin,South China Sea[J].Marine geology,2016,378:101-113.DOI:10.1016/j.margeo.2015.11.002.
[21]刘方兰,吴庐山.西沙海槽海域地形地貌特征及成因[J].海洋地质与第四纪地质,2006,26(3):7-14.DOI:10.16562/j.cnki.0256-1492.2006.03.002.
[22]ZENG L L,WANG Q,XIE Q,et al.Hydrographic field investigations in the Northern South China Sea by open cruises during 2004-2013[J].Science bulletin,2015,60(6):607-615.DOI:10.1007/s11434-015-0733-z.
[23]NISSEN S S,HAYES D E,YAO B C,et al.Gravity,heat flow,and seismic constraints on the processes of crustal extension:northern margin of the South China Sea[J].Journal of geophysical research:solid earth,1995,100(B11):22447-22483.DOI:10.1029/95JB01868.
[24]SHI X B,JIANG H Y,YANG J,et al.Models of the rapid post-rift subsidence in the eastern Qiongdongnan Basin,South China Sea:implications for the development of the deep thermal anomaly[J].Basin research,2017,29(3):340-362.DOI:10.1111/bre.12179.
[25]徐行,施小斌,罗贤虎,等.南海西沙海槽地区的海底热流测量[J].海洋地质与第四纪地质,2006,26(4):51-58.DOI:10.16562/j.cnki.0256-1492.2006.04.008.
[26]李亚敏,罗贤虎,徐行,等.南海北部陆坡深水区的海底原位热流测量[J].地球物理学报,2010,53(9):2161-2170.DOI:10.3969/j.issn.0001-5733.2010.09.016.
[27]施小斌,于传海,陈梅,等.南海北部陆缘热流变化特征及其影响因素分析[J].地学前缘,2017,24(3):56-64.DOI:10.13745/j.esf.2017.03.005.
[28]KIENAST M,STEINKE S,STATTEGGER K,et al.Synchronous tropical South China Sea SST change and Greenland warming during deglaciation[J].Science,2001,291(5511):2132-2134.DOI:10.1126/science.1057131.
[29]BATES S L,SIDDALL M,WAELBROECK C.Hydrographic variations in deep ocean temperature over the mid-Pleistocene transition[J].Quaternary science reviews,2014,88:147-158.DOI:10.1016/j.quascirev.2014.01.020.
[30]SHAO L,CUI Y C,QIAO P J,et al.Sea-level changes and carbonate platform evolution of the Xisha Islands(South China Sea)since the Early Miocene[J].Palaeogeography,palaeoclimatology,palaeoecology,2017,485:504-516.DOI:10.1016/j.palaeo.2017.07.006.
[31]WANG P X.Response of Western Pacific marginal seas to glacial cycles:paleoceanographic and sedimentological features[J].Marine geology,1999,156(1/4):5-39.DOI:10.1016/S0025-3227(98)00172-8.
[32]黄维,汪品先.南海深水区末次冰期和冰后期沉积物堆积速率的特征[J].海洋学报,2007,29(5):69-73.DOI:10.3321/j.issn:0253-4193.2007.05.008.
[33]李学杰.南海西部沉积特征及其从晚更新世以来的变化[D].上海:同济大学,2005.
[34]BURWICZ E,REICHEL T,WALLMANN K,et al.3-Dbasin-scale reconstruction of natural gas hydrate system of the Green Canyon,Gulf of Mexico[J].Geochemistry,geophysics,geosystems,2017,18(5):1959-1985.DOI:10.1002/2017GC006876.
[35]HORNBACH M J,SAFFER D M,HOLBROOK W S.Critically pressured free-gas reservoirs below gas-hydrate provinces[J].Nature,2004,427(6970):142-144.DOI:10.1038/nature02172.
[36]TORRES M E,WALLMANN K,TRéHU A M,et al.Gas hydrate growth,methane transport,and chloride enrichment at the southern summit of Hydrate Ridge,Cascadia margin off Oregon[J].Earth and planetary science letters,2004,226(1/2):225-241.DOI:10.1016/j.epsl.2004.07.029.
[37]LINKE P,WALLMANN K,SUESS E,et al.In situ benthic fluxes from an intermittently active mud volcano at the Costa Rica convergent margin[J].Earth and planetary science letters,2005,235(1/2):79-95.DOI:10.1016/j.epsl.2005.03.009.
[2]于晓果,李家彪.天然气水合物分解及其生态环境效应研究迚展[J].地球科学迚展,2004,19(6):947-954.DOI:10.3321/j.issn:1001-8166.2004.06.012.
[3]陈忠,颜文,陈木宏,等.海底天然气水合物分解与甲烷归宿研究迚展[J].地球科学迚展,2006,21(4):394-400.DOI:10.3321/j.issn:1001-8166.2006.04.008.
[4]MILKOV A V.Global estimates of hydrate-bound gas in marine sediments:how much is really out there?[J].Earth-science reviews,2004,66(3/4):183-197.DOI:10.1016/j.earscirev.2003.11.002.
[5]MéNOT G,BARD E.Geochemical evidence for a large methane release during the last deglaciation from Marmara Sea sediments[J].Geochimica et cosmochimica acta,2010,74(5):1537-1550.DOI:10.1016/j.gca.2009.11.022.
[6]PLAZA-FAVEROLA A,BüNZ S,MIENERT J.Repeated fluid expulsion through sub-seabed chimneys offshore Norway in response to glacial cycles[J].Earth and planetary science letters,2011,305(3/4):297-308.DOI:10.1016/j.epsl.2011.03.001.
[7]KENNETT J P,CANNARIATO K G,HENDY I L,et al.Carbon isotopic evidence for methane hydrate instability during quaternary interstadials[J].Science,2000,288(5463):128-133.DOI:10.1126/science.288.5463.128.
[8]叶黎明,初凤友,葛倩,等.新仙女木末期南海北部天然气水合物分解事件[J].地球科学-中国地质大学学报,2013,38(6):1299-1308.DOI:10.3799/dqkx.2013.127.
[9]WALLMANN K,PINERO E,BURWICZ E,et al.The global inventory of methane hydrate in marine sediments:a theoretical approach[J].Energies,2012,5(7):2449-2498.DOI:10.3390/en5072449.
[10]苏新,陈芳,于兴河,等.南海陆坡中新世以来沉积物特性与气体水合物分布初探[J].现代地质,2005,19(1):1-13.DOI:10.3969/j.issn.1000-8527.2005.01.001.
[11]苏明,杨睿,张翠梅,等.深水沉积体系研究迚展及其对南海北部陆坡区天然气水合物研究的启示[J].海洋地质与第四纪地质,2013,33(3):109-116.
[12]赵广明,叶思源,丁喜桂,等.黄河三角洲全新世以来沉积环境的划分及各环境中碳埋藏速率的评价[J].地球科学-中国地质大学学报,2014,39(4):451-461.DOI:10.3799/dqkx.2014.043.
[13]GUAN J A,LIANG D Q,WU N Y,et al.The methane hydrate formation and the resource estimate resulting from free gas migration in seeping seafloor hydrate stability zone[J].Journal of Asian earth sciences,2009,36(4/5):277-288.DOI:10.1016/j.jseaes.2009.05.008.
[14]TRUNG N N.The gas hydrate potential in the South China Sea[J].Journal of petroleum science and engineering,2012,88-89:41-47.DOI:10.1016/j.petrol.2012.01.007.
[15]王淑红,颜文,宋海斌.末次盛冰期以来西沙海槽天然气水合物储库变化及其对环境的影响[J].地球科学-中国地质大学学报,2008,33(1):74-82.DOI:10.3321/j.issn:1000-2383.2008.01.010.
[16]孙春岩,牛滨华,文鹏飞,等.海上E区天然气水合物地质、地震、地球化学特征综合研究与成藏进景预测[J].地球物理学报,2004,47(6):1076-1085.DOI:10.3321/j.issn:0001-5733.2004.06.021.
[17]苏明,张成,解习农,等.深水峡谷体系控制因素分析-以南海北部琼东南盆地中央峡谷体系为例[J].中国科学:地球科学,2014,44(8):1807-1820.
[18]姚悦,周江羽,雷振宇,等.西沙海槽盆地强限制性中央峡谷水道地震相与内部结构的分段特征[J].沉积学报,2018,36(4):787-795.DOI:10.14027/j.issn.1000-0550.2018.048.
[19]QIN Z L,WU S G,WANG D W,et al.Mass transport deposits and processes in the north slope of the Xisha Trough,northern South China Sea[J].Acta oceanologica sinica,2015,34(9):117-125.DOI:10.1007/s13131-015-0608-9.
[20]CHEN H,XIE X N,ZHANG W Y,et al.Deep-water sedimentary systems and their relationship with bottom currents at the intersection of Xisha Trough and Northwest Sub-Basin,South China Sea[J].Marine geology,2016,378:101-113.DOI:10.1016/j.margeo.2015.11.002.
[21]刘方兰,吴庐山.西沙海槽海域地形地貌特征及成因[J].海洋地质与第四纪地质,2006,26(3):7-14.DOI:10.16562/j.cnki.0256-1492.2006.03.002.
[22]ZENG L L,WANG Q,XIE Q,et al.Hydrographic field investigations in the Northern South China Sea by open cruises during 2004-2013[J].Science bulletin,2015,60(6):607-615.DOI:10.1007/s11434-015-0733-z.
[23]NISSEN S S,HAYES D E,YAO B C,et al.Gravity,heat flow,and seismic constraints on the processes of crustal extension:northern margin of the South China Sea[J].Journal of geophysical research:solid earth,1995,100(B11):22447-22483.DOI:10.1029/95JB01868.
[24]SHI X B,JIANG H Y,YANG J,et al.Models of the rapid post-rift subsidence in the eastern Qiongdongnan Basin,South China Sea:implications for the development of the deep thermal anomaly[J].Basin research,2017,29(3):340-362.DOI:10.1111/bre.12179.
[25]徐行,施小斌,罗贤虎,等.南海西沙海槽地区的海底热流测量[J].海洋地质与第四纪地质,2006,26(4):51-58.DOI:10.16562/j.cnki.0256-1492.2006.04.008.
[26]李亚敏,罗贤虎,徐行,等.南海北部陆坡深水区的海底原位热流测量[J].地球物理学报,2010,53(9):2161-2170.DOI:10.3969/j.issn.0001-5733.2010.09.016.
[27]施小斌,于传海,陈梅,等.南海北部陆缘热流变化特征及其影响因素分析[J].地学前缘,2017,24(3):56-64.DOI:10.13745/j.esf.2017.03.005.
[28]KIENAST M,STEINKE S,STATTEGGER K,et al.Synchronous tropical South China Sea SST change and Greenland warming during deglaciation[J].Science,2001,291(5511):2132-2134.DOI:10.1126/science.1057131.
[29]BATES S L,SIDDALL M,WAELBROECK C.Hydrographic variations in deep ocean temperature over the mid-Pleistocene transition[J].Quaternary science reviews,2014,88:147-158.DOI:10.1016/j.quascirev.2014.01.020.
[30]SHAO L,CUI Y C,QIAO P J,et al.Sea-level changes and carbonate platform evolution of the Xisha Islands(South China Sea)since the Early Miocene[J].Palaeogeography,palaeoclimatology,palaeoecology,2017,485:504-516.DOI:10.1016/j.palaeo.2017.07.006.
[31]WANG P X.Response of Western Pacific marginal seas to glacial cycles:paleoceanographic and sedimentological features[J].Marine geology,1999,156(1/4):5-39.DOI:10.1016/S0025-3227(98)00172-8.
[32]黄维,汪品先.南海深水区末次冰期和冰后期沉积物堆积速率的特征[J].海洋学报,2007,29(5):69-73.DOI:10.3321/j.issn:0253-4193.2007.05.008.
[33]李学杰.南海西部沉积特征及其从晚更新世以来的变化[D].上海:同济大学,2005.
[34]BURWICZ E,REICHEL T,WALLMANN K,et al.3-Dbasin-scale reconstruction of natural gas hydrate system of the Green Canyon,Gulf of Mexico[J].Geochemistry,geophysics,geosystems,2017,18(5):1959-1985.DOI:10.1002/2017GC006876.
[35]HORNBACH M J,SAFFER D M,HOLBROOK W S.Critically pressured free-gas reservoirs below gas-hydrate provinces[J].Nature,2004,427(6970):142-144.DOI:10.1038/nature02172.
[36]TORRES M E,WALLMANN K,TRéHU A M,et al.Gas hydrate growth,methane transport,and chloride enrichment at the southern summit of Hydrate Ridge,Cascadia margin off Oregon[J].Earth and planetary science letters,2004,226(1/2):225-241.DOI:10.1016/j.epsl.2004.07.029.
[37]LINKE P,WALLMANN K,SUESS E,et al.In situ benthic fluxes from an intermittently active mud volcano at the Costa Rica convergent margin[J].Earth and planetary science letters,2005,235(1/2):79-95.DOI:10.1016/j.epsl.2005.03.009.