A Rapid Gas Hydrate Dissociation in the Northern South China Sea since the Late Younger Dryas
-
摘要: 深海天然气水合物分解与全球变暖密切相关.南海北部是重要的天然气水合物蕴藏区，ZHS-176、ZHS-174、17940和MD2905孔CaCO3含量记录均表明，11.3~8.0 ka B.P.神狐海域存在一次典型的“低钙事件”(CM)，该事件具有“快速降低、缓慢升高”不对称的变化结构，CaCO3含量降幅高达9%.“低钙事件”期间，底栖有孔虫Cibicidoides wuellerstorfi和Cibicidoides kullenbergi壳体δ13C分别负偏了1.4 ‰和0.7 ‰，海底有机碳的堆积速率(MAR)也突然升高了1倍.综合分析表明，新仙女木末期南海北部天然气水合物很可能发生了一次较大规模的快速分解，大量甲烷气体从天然气水合物中逸散，氧化后使底层海水快速酸化，从而导致了神狐海域碳酸盐的溶解.底层水团温度上升很可能是神狐海域天然气水合物分解的主要触发因素.Abstract: Gas hydrate in the deep sea is closely related to the global warming. One of the most important gas hydrate stability zones (GHSZ) is located in the Shenhu of the northern South China Sea (SCS). All records of carbonate content in cores ZHS-176, ZHS-174, 17940 and MD2905 reveal a carbonate minimum (CM) from 11.3-8.0 ka B.P., which is characterized with an asymmetric pattern of a rapid decrease of 9% value followed by a gradual recovery. The benthic foraminifer δ13C levels in the shells of Cibicidoides wuellerstorfi and Cibicidoides kullenbergi are depleted by 1.4‰ and 0.7‰, respectively, during the CM period. Meanwhile, the mass accumulation rate (MAR) of the organisms suddenly increased nearly twofold on the seabed. These findings indicate a likely release of a large amount of methane from the gas hydrates since the late Younger Dryas (YD). Oxidation and absorption of the methane should have lowered pH of the bottom seawater, thereby triggering a shoaling of the carbonate lysocline. Temperature increasing of the bottom seawater in the northern SCS provides a possibility to induce gas hydrates dissociation.
-
Key words:
- global warming /
- the South China Sea /
- Younger Dryas /
- gas hydrate /
- seawater
-
图 1 南海北部地形及站位
三角形代表本研究实测站位，十字符代表参考站位，条带状阴影指示珠江口海底峡谷
Fig. 1. Schematic geographical map of the northern SCS and the location of the cores
图 2 南海周边“低钙事件”对比
箭头代表AMS14C测年点，ZHS-176孔AMS14C测年数据葛倩等(2008), 17940引自Jian et al.(1999), MD2905杨文光等(2008), MD2142引自Chen et al.(2003), SA12-19李学杰和江茂生(2003), MD2151引自Zhao et al.(2006)；灰色框指示“低钙事件”
Fig. 2. Comparison of the CMs around the SCS
图 3 神狐海域“低钙事件”剖面
箭头及数据指示B64孔AMS14C测年层位及年代; 南海17940孔CaCO3含量引自Wang et al.(1999)，其他各孔数据为本次分析结果；灰色框指示“低钙事件”
Fig. 3. The section of the CM in the Shenhu area
图 4 神狐海域“低钙事件”期间各种环境指标的变化特征
1266C孔CaCO3含量和δ13C引自Zachos et al.(2005); 南海17940孔CaCO3含量、底栖有孔虫C.wuellerstorfi和C.kullerbergi壳体δ13C引自Wang et al.(1999); 17940孔Corg MAR引自Jian et al.(1999); 海平面变化及上升速率数据引自Hanebuth et al.(2000); 湖光岩玛珥湖Ti元素含量和太阳辐射量引自Yancheva et al.(2007)
Fig. 4. Comparison of the different environmental proxies against the CM
表 1 主要沉积物柱状样站位信息
Table 1. Location of the studied cores
钻孔 经度E 纬度N 水深(m) 17940 117°23.0′ 20°07.0′ 1 727 MD2905 117°21.6′ 20°08.2′ 1 647 MD2142 119°27.9′ 12°41.1′ 1 557 MD2151 109°52.2′ 8°43.7′ 1 598 SA12-19 110°25.4′ 17°09.2′ 1 300 ZHS-176 115°33.3′ 20°00.0′ 1 383 ZHS-174 115°30.2′ 20°10.2′ 640 B64 112°28.8′ 21°33.1′ 19 注：17940引自 Jian et al.(1999) 和Wang et al.(1999) ，MD2905杨文光等(2008)，MD2142引自Chen et al.(2003) ，MD2151引自Huang et al.(1999) 和Zhao et al.(2006) ，SA12-19李学杰和江茂生(2003)，ZHS-176、ZHS-174和B64为本次研究站位.
下载: 导出CSV
-
[1] Alley, R.B., 2000. The Younger Dryas Cold Interval as Viewed from Central Greenland. Quaternary Science Reviews, 19: 213-226. doi: 10.1016/S0277-3791(99)00062-1 [2] Alley, R.B., Meeset, A.D., Shuman, C. A, et al., 1993. Abrupt Increase in Greenland Snow Accumulation at the End of the Younger Dryas Event. Nature, 362: 527-529. doi: 10.1038/362527a0 [3] Archer, D., 2007. Methane Hydrate Stability and Anthropogenic Climate Change. Biogeosciences, 4: 521-544. doi: 10.5194/bg-4-521-2007 [4] Blunier, T., Brook, E.J., 2001. Timing of Millennial-Scale Climate Change in Antarctica and Greenland during the Last Glacial Period. Science, 291(5501): 109-112. doi: 10.1126/science.291.5501.109 [5] Bock, M., Schmitt, J., Moller, L., et al., 2010. Hydrogen Isotopes Preclude Marine Hydrate CH4 Emissions at the Onset of Dansgaard-Oeschger Events. Science, 328(5986): 1686-1689. doi: 10.1126/science.1187651 [6] Bond, G., Broecker, W., Johnsen, S., et al., 1993. Correlations between Climate Records from North Atlantic Sediments and Greenland Ice. Nature, 365: 143-147. doi: 10.1038/365143a0 [7] Chen, M.T., Shiau, L.J., Yu, P.S., et al., 2003.500 000-Year Records of Carbonate, Organic Carbon, and Foraminiferal Sea-Surface Temperature from the South Eastern South China Sea (near Palawan Island). Paleogeography, Palaeoclimatology, Palaeoecology, 197: 113-131. doi: 10.1016/S0031-0182(03)00389-4 [8] Chen, R.H., Xu, J., Meng, Y., et al., 2003. Microorganisms and Carbonate Lysocline Depth and CCD in Surface Sediment of the Northeastern South China Sea. Acta Oceanologica Sinica, 25(2): 48-56 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/ http://search.cnki.net/down/default.aspx?filename=SEAC200302005&dbcode=CJFD&year=2003&dflag=pdfdown [9] Chen, Z., Yan, W., Chen, M.H., et al., 2006. Discovery of Seep Carbonate Nodules as New Evidence for Gas Venting on the Northern Continental Slope of South China Sea. Chinese Science Bulletin, 51(9): 1065-1072 (in Chinese with English abstract). doi: 10.1007/s11434-006-1065-9 [10] Dansgaard, W., Johnsen, S.J., Clausen, H.B., et al., 1993. Evidence for General Instability of Past Climate from a 250-kyr Ice-Core Record. Nature, 364: 218-220. doi: 10.1038/364218a0 [11] Dickens, G.R., 2001. The Potential Volume of Oceanic Methane Hydrates with Variable External Conditions. Organic Geochemistry, 32(10): 1179-1193. doi: 10.1016/S0146-6380(01)00086-9 [12] Dickens, G.R., 2003. Rethinking the Global Carbon Cycle with a Large, Dynamic and Microbially Mediated Gas Hydrate Capacitor. Earth and Planetary Science Letters, 213(3-4): 169-183. doi: 10.1016/S0012-821X(03)00325-X [13] Dickens, G.R., 2011. Down the Rabbit Hole: Toward Appropriate Discussion of Methane Release from Gas Hydrate Systems during the Paleocene-Eocene Thermal Maximum and Other Past Hyper Thermal Events. Climate of the Past, 7: 831-846. doi: 10.5194/cp-7-831-2011 [14] EPICA Community Members, 2006. One-to-One Coupling of Glacial Climate Variability in Greenland and Antarctica. Nature, 444: 195-198. doi: 10.1038/nature05301 [15] Ge, Q., Meng, X.W., Chu, F.Y., et al., 2008. The Carbonate Cycles in the Northern South China Sea during the Last 30 ka and the Paleoclimatic Significance. Journal of Marine Sciences, 26(1): 18-21 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DHHY200801002.htm [16] Ge, Q., Wang J.S., Xiang, H., et al., 2006. Computation of Thickness of Gas Hydrate Stability Zone and Potential Volume of Gas Hydrate in South China Sea. Earth Science—Journal of China University of Geosciences, 31(2): 245-249 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQKX200602014.htm [17] Han, X., Suess, E., Huang, Y., et al., 2008. Jiulong Methane Reef: Microbial Mediation of Seep Carbonates in the South China Sea. Marine Geology, 249(3-4): 243-256. doi: 10.1016/j.margeo.2007.11.012 [18] Hanebuth, T., Stattegger, K., Grootes, P.M., 2000. Rapid Flooding of the Sunda Shelf: A Late-Glacial Sea-Level Record. Science, 288(5468): 1033-1035. doi: 10.1126/science.288.5468.1033 [19] Heaton, T.J., Blackwell, P.G., Buck, C.E., 2009. A Bayesian Approach to the Estimation of Radiocarbon Calibration Curves: The INTCAL09 Methodology. Radiocarbon, 51(4): 1151-1164. doi: 10.1017/S0033822200034214 [20] Huang, C.Y., Wang, C.C., Zhao, M, 1999. High-Resolution Carbonate Stratigraphy of IMAGES Core MD972151 from South China Sea. Tao, 10(1): 225-238. http://www.researchgate.net/profile/Meixun_Zhao/publication/253817100_High-resolution_Carbonate_Stratigraphy_of_IMAGES_Core_MD972151_from_South_China_Sea/links/53f821460cf24ddba7db2cf1 [21] Jian, Z., Wang, L., Kienast, M., et al., 1999. Benthic Foraminiferal Paleoceanography of the South China Sea over the Last 40 000 Years. Marine Geology, 156(1): 159-186. doi: 10.1016/S0025-3227(98)00177-7 [22] Jiang, G.Q., Shi, X.Y., Zhang, S.H., 2006. Methane Seeps, Methane Hydrate Destabilization, and the Late Neoproterozoic Postglacial Cap Carbonates. Chinese Science Bulletin, 51(10): 1152-1173. doi: 10.1007/s11434-006-1152-y [23] Kennett, J.P., Cannariato, K.G., Hendy, I.L., et al., 2000. Carbon Isotopic Evidence for Methane Hydrate Instability during Quaternary Interstadials. Science, 288(5463): 128-133. doi: 10.1126/science.288.5463.128 [24] Kvenvolden, K.A., Lilley, M.D., Lorenson, T.D., 1993. The Beaufort Sea Continental Shelf as a Seasonal Source of Atmospheric Methane. Geophysical Research Letters, 20(22): 2459-2462. doi: 10.1029/93GL02727 [25] Li, L., Wang, H., Luo, B.C.R., et al., 2008. The Characterizations and Paleoceanographic Significances of Organic and Inorganic Carbon in Northern South China Sea during Past 40 ka. Marine Geology & Quaternary Geology, 28(6): 79-85 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-HYDZ200806013.htm [26] Li, X.J., Jiang, M.S., 2003. Low Carbonate Event in Northern South China Sea during the Early Holocene and Their Paleoclimatic Significance. Journal of Palaeogeography, 5(3): 355-364 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-GDLX200303007.htm [27] Liu, J.P., Xue, Z., Ross, K., et al., 2009. Fate of Sediments Delivered to the Sea by Asian Large Rivers: Long-Distance Transport and Formation of Remote Alongshore Clinotherms. The Sedimentary Record, 7(4): 4-9. doi: 10.2110/sedred.2009.4.4 [28] Lutaenko, K.A., Xu, F., 2008. A Catalogue of Types of Bivalve Mollusks in the Marine Biological Museum, Chinese Academy of Sciences (Qingdao). The Bulletin of the Russian Far East Malacological Society, 12: 42-70. http://www.researchgate.net/publication/299505775_Lutaenko_KA_Xu_F_A_catalogue_of_types_of_bivalve_mollusks_in_the_Marine_Biological_Museum_Chinese_Academy_of_Sciences_Qingdao_Bulletin_of_the_Russian_Far_East_Malacological_Society_2008_v_12_pp_42-70_ [29] Nisbet, E, 1990. Climate Change and Methane. Nature, 347: 23. doi: 10.1038/347023a0 [30] Nisbet, E.G., Chappellaz, J., 2009. Shifting Gear, Quickly. Science, 324(5926): 477-478. doi: 10.1126/science.1172001 [31] Paull, C.K., Brewer, P.G., UsslerⅢ, W., et al., 2003. An Experiment Demonstrating that Marine Slumping is a Mechanism to Transfer Methane from Seafloor Gas-Hydrate Deposits into the Upper Ocean and Atmosphere. Geo-Marine Letters, 22(4): 198-203. doi: 10.1007/s00367-002-0113-y [32] Petrenko, V.V., Smith, A.M., Brook, E.J., et al., 2009. 14CH4 Measurements in Greenland Ice: Investigating Last Glacial Termination CH4 Sources. Science, 324(5926): 506-508. doi: 10.1126/science.1168909 [33] Schrag, D.P., Hampt, G., Murray, D.W., 1996. Pore Fluid Constraints on the Temperature and Oxygen Isotopic Composition of the Glacial Ocean. Science, 272(5270): 1930-1932. doi: 10.1126/science.272.5270.1930 [34] Severinghaus, J.P., Sowers, T., Brook, E.J., et al., 1998. Timing of Abrupt Climate Change at the End of the Younger Dryas Interval from Thermally Fractionated Gases in Polar Ice. Nature, 391: 141-146. doi: 10.1038/34346 [35] Sowers, T., 2006. Late Quaternary Atmospheric CH4 Isotope Record Suggests Marine Clatherates are Stable. Science, 311(5762): 838-840. doi: 10.1126/science.1121235 [36] Su, X., 2004. Marine Gas Hydrates Distribution and Dynamic System of Gas-Water-Sediment. Science in China (Series D), 34(12): 1091-1099 (in Chinese with English abstract). [37] Suess, E., 2005. FS Sonne Fahrtbericht/Cruise Report SO177, Siger 2004, Sino-German Cooperative Project, South China Sea Continental Margin: Geological Methane Budget and Environmental Effects of Methane Emissions and Gas Hydrates. In: IFM-GEOMAR Reports. Earth & Environmental Science, Wolfvile. [38] Villasante-Marcos, V., Hollis, C.J., Dickens, G.R., et al., 2009. Rock Magnetic Properties across the Paleocene-Eocene Thermal Maximum in Marlborough, New Zealand. Geologica Acta, 7(1-2): 229-242. doi: 10.1344/105.000000280 [39] Voris, H.K., 2000. Maps of Pleistocene Sea Levels in Southeast Asia: Shorelines, River Systems and Time Durations. Journal of Biogeography, 27(5): 1153-1167. doi: 10.1046/j.1365-2699.2000.00489.x [40] Walker, J.C.G., Kasting, J.F., 1992. Effects of Fuel and Forest Conservation on Future Levels of Atmospheric Carbon Dioxide. Palaeogeography, Palaeoclimatology, Palaeoecology, 97: 151-189. doi: 10.1016/0031-0182(92)90207-L [41] Wang, L., Jian, Z., Chen, J., 1997. Late Quaternary Pteropods in the South China Sea: Carbonate Preservation and Paleoenvironmental Variation. Marine Micropaleontology, 32(1-2): 115-126. doi: 10.1016/S0377-8398(97)00016-9 [42] Wang, L., Sarnthein, M., Erlenkeuser, H., et al., 1999. East Asian Monsoon Climate during the Late Pleistocene: High-Resolution Sediment Records from the South China Sea. Marine Geology, 156: 245-284. doi: 10.1016/S0025-3227(98)00182-0 [43] Wu, N., Dong, H., Suess, E., 2006. Mineralogical Features and C-O Isotope Composition of Methane-Derived Carbonate Build-up Found in the Northeastern South China Sea. Western Pacific Geophysics Meeting, EOS Transactions, AGU Abstract (87), Hawaii, OS41F-01. [44] Yancheva, G., Nowaczyk, N.R., Mingram, J., et al., 2007. Influence of the Intertropical Convergence Zone on the East Asian Monsoon. Nature, 445: 74-77. doi: 10.1038/nature05431 [45] Yang, T., Jiang, S.Y., Ge, L., et al., 2010. Geochemical Characteristics of Pore Water in Shallow Sediments from Shenhu Area of South China Sea and Their Significance for Gas Hydrate Occurrence. Chinese Science Bulletin, 54(20): 3231-3240 (in Chinese with English abstract). [46] Yang, W.G., Zheng, H.B., Xie, X., et al., 2008. East Asian Summer Monsoon Maximum Records in Northern South China Sea during the Early Holocene. Quaternary Sciences, 28(3): 425-430 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DSJJ200803006.htm [47] Yuan, D., Cheng, H., Edwards, R.L., et al., 2004. Timing, Duration, and Transitions of the Last Interglacial Asian Monsoon. Science, 304(5670): 575-578. doi: 10.1126/science.1091220 [48] Zachos, J.C., Rohl, U., Schellenberg, S.A., et al., 2005. Rapid Acidification of the Ocean during the Paleocene-Eocene Thermal Maximum. Science, 308(5728): 1611-1615. doi: 10.1126/science.1109004 [49] Zhang, H., Yang, S., Wu, N., et al., 2007. China's First Gas Hydrate Expedition Successful. Methane Hydrate Newsletter, 7(2): 1. [50] Zhao, M., Huang, C.Y., Wang, C.C., et al., 2006. A Millennial-Scale U37k Sea-Surface Temperature Record from the South China Sea (8°N) over the Last 150 kyr: Monsoon and Sea-Level Influence. Palaeogeography, Palaeoclimatology, Palaeoecology, 236: 39-55. doi: 10.1016/j.palaeo.2005.11.033 [51] Zhou, B., Zheng, H.B., Yang, W.G., et al., 2008. Provenance and Paleo-Environment Changes in the Northern Part of South China Sea since the Last Glacial Period as Recorded by Organic Geochemistry Proxies. Quaternary Sciences, 28(3): 407-416 (in Chinese with English abstract). http://d.wanfangdata.com.cn/Periodical_dsjyj200803004.aspx [52] 陈荣华, 徐建, 孟翊, 等, 2003. 南海东北部表层沉积中微体化石与碳酸盐溶跃面和补偿深度. 海洋学报, 25(2): 48-56. doi: 10.3321/j.issn:0253-4193.2003.02.006 [53] 陈忠, 颜文, 陈木宏, 等, 2006. 南海北部大陆坡冷泉碳酸盐结核的发现: 海底天然气渗漏活动的新证据. 科学通报, 51(9): 1065-1072. doi: 10.3321/j.issn:0023-074X.2006.09.011 [54] 葛倩, 孟宪伟, 初凤友, 等, 2008. 近3万年来南海北部碳酸盐旋回及古气候意义. 海洋学研究, 26(1): 18-21. doi: 10.3969/j.issn.1001-909X.2008.01.003 [55] 葛倩, 王家生, 向华, 等, 2006. 南海天然水合物稳定带厚度及资源量估算. 地球科学——中国地质大学学报, 31(2): 245-249. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX200602014.htm [56] 李丽, 王慧, 罗布次仁, 等, 2008. 南海北部4万年以来有机碳和碳酸盐含量变化及古海洋学意义. 海洋地质与第四纪地质, 28(6): 79-85. https://www.cnki.com.cn/Article/CJFDTOTAL-HYDZ200806013.htm [57] 李学杰, 江茂生, 2003. 南海北部全新世早期低钙事件及其古气候解释. 古地理学报, 5(3): 355-364. doi: 10.3969/j.issn.1671-1505.2003.03.008 [58] 苏新, 2004. 海洋天然气水合物分布与"气-水-沉积物"动态体系. 中国科学(D辑), 34(12): 1091-1099. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK200412000.htm [59] 杨涛, 蒋少涌, 葛璐, 等, 2009. 南海北部神狐海域浅表层沉积物中孔隙水的地球化学特征及其对天然气水合物的指示意义. 科学通报, 54(20): 3231-3240. https://www.cnki.com.cn/Article/CJFDTOTAL-KXTB200920038.htm [60] 杨文光, 郑洪波, 谢昕, 等, 2008. 南海北部陆坡沉积记录的全新世早期夏季风极强事件. 第四纪研究, 28(3): 425-430. doi: 10.3321/j.issn:1001-7410.2008.03.006 [61] 周斌, 郑洪波, 杨文光, 等, 2008. 末次冰期以来南海北部物源及古环境变化的有机地球化学记录. 第四纪研究, 28(3): 407-416. doi: 10.3321/j.issn:1001-7410.2008.03.004 -
点击查看大图
图(4) / 表(1)
计量
- 文章访问数: 9851
- HTML全文浏览量: 186
- PDF下载量: 1590
- 被引次数: 0
