Abstract
Previous studies of gas hydrate in the Dongsha area mainly focused on the deep-seated gas hydrates that have a high energy potential, but cared little about the shallow gas hydrates occurrences. Shallow gas hydrates have been confirmed by drill cores at three sites (GMGS2 08, GMGS2 09 and GMGS2 16) during the GMGS2 cruise, which occur as veins, blocky nodules or massive layers, at 8–30 m below the seafloor. Gas chimneys and faults observed on the seismic sections are the two main fluid migration pathways. The deep-seated gas hydrate and the shallow hydrate-bearing sediments are two main seals for the migrating gas. The occurrences of shallow gas hydrates are mainly controlled by the migration of fluid along shallow faults and the presence of deep-seated gas hydrates. Active gas leakage is taking place at a relatively high-flux state through the vent structures identified on the geophysical data at the seafloor, although without resulting in gas plumes easily detectable by acoustic methods. The presence of strong reflections on the high-resolution seismic profiles and dim or chaotic layers in the sub-bottom profiles are most likely good indicators of shallow gas hydrates in the Dongsha area. Active cold seeps, indicated by either gas plume or seepage vent, can also be used as indicators for neighboring shallow gas hydrates and the gas hydrate system that is highly dynamic in the Dongsha area.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Attias E, Weitemeyer K, Minshull T A, et al. 2016. Controlled-source electromagnetic and seismic delineation of subseafloor fluid flow structures in a gas hydrate province, offshore Norway. Geophysical Journal International, 206(2): 1093–1110, doi: https://doi.org/10.1093/gji/ggw188
Bahk J J, Kim J H, Kong G S, et al. 2009. Occurrence of near-seafloor gas hydrates and associated cold vents in the Ulleung Basin, East Sea. Geosciences Journal, 13(4): 371–385, doi: https://doi.org/10.1007/s12303-009-0039-8
Bangs N L B, Sawyer D S, Golovchenko X. 1993. Free gas at the base of the gas hydrate zone in the vicinity of the Chile triple junction. Geology, 21(10): 905–908, doi: https://doi.org/10.1130/0091-7613(1993)021<0905:FGATBO>2.3.CO;2
Berndt C, Bunz S, Clayton T, et al. 2004. Seismic character of bottom simulating reflectors: examples from the mid-Norwegian margin. Marine and Petroleum Geology, 21(6): 723–733, doi: https://doi.org/10.1016/j.marpetgeo.2004.02.003
Boswell R, Collett T S. 2011. Current perspectives on gas hydrate resources. Energy & Environmental Science, 4(4): 1206–1215
Boswell R, Shipp C, Reichel T, et al. 2016. Prospecting for marine gas hydrate resources. Interpretation, 4(1): SA13–SA24, doi: https://doi.org/10.1190/INT-2015-0036.1
Chen Duofu, Huang Yongyang, Yuan Xunlai, et al. 2005. Seep carbonates and preserved methane oxidizing archaea and sulfate reducing bacteria fossils suggest recent gas venting on the sea-floor in the northeastern South China Sea. Marine and Petroleum Geology, 22(5): 613–621, doi: https://doi.org/10.1016/j.marpetgeo.2005.05.002
Chen Duofu, Su Zheng, Cathles L M. 2006. Types of gas hydrates in marine environments and their thermodynamic characteristics. Terrestrial, Atmospheric and Oceanic Sciences, 17(4): 723–737, doi: https://doi.org/10.3319/TAO.2006.17.4.723(GH)
Chen Fang, Hu Yu, Feng Dong, et al. 2016. Evidence of intense methane seepages from molybdenum enrichments in gas hydrate-bearing sediments of the northern South China Sea. Chemical Geology, 1: 173–181, doi: https://doi.org/10.1016/j.chemgeo.2016.09.029
Chen Jiangxin, Guan Yongxian, Song Haibin, et al. 2015a. Distribution characteristics and geological implications of pockmarks and mud volcanoes in the northern and western continental margins of the South China Sea. Chinese Journal of Geophysics (in Chinese), 58(3): 919–938
Chen Jiangxin, Song Haibin, Guan Yongxian, et al. 2015b. Morphologies, classification and genesis of pockmarks, mud volcanoes and associated fluid escape features in the northern Zhongjiannan Basin, South China Sea. Deep Sea Research Part II: Topical Studies in Oceanography, 1: 106–117, doi: https://doi.org/10.1016/j.dsr2.2015.11.007
Chen Jiangxin, Song Haibin, Guan Yongxian, et al. 2018. Geological and oceanographic controls on seabed fluid escape structures in the northern Zhongjiannan Basin, South China Sea. Journal of Asian Earth Sciences, 1: 8–47
Etiope G, Milkov A V, Derbyshire E. 2008. Did geologic emissions of methane play any role in Quaternary climate change?. Global and Planetary Change, 61(1–2): 79–88, doi: https://doi.org/10.1016/j.gloplacha.2007.08.008
Feng Dong, Chen Duofu. 2015. Authigenic carbonates from an active cold seep of the northern South China Sea: New insights into fluid sources and past seepage activity. Deep Sea Research Part II: Topical Studies in Oceanography, 1: 74–83, doi: https://doi.org/10.1016/j.dsr2.2015.02.003
Feng Dong, Qiu Jianwen, Hu Yu, et al. 2018. Cold seep systems in the South China Sea: An overview. Journal of Asian Earth Sciences, 1: 3–16, doi: https://doi.org/10.1016/j.jseaes.2018.09.021
Foucher J P, Westbrook G K, Boetius A, et al. 2009. Structure and drivers of cold seep ecosystems. Oceanography, 22(1): 92–109, doi: https://doi.org/10.5670/oceanog.2009.11
Gardner J M. 2001. Mud volcanoes revealed and sampled on the western moroccan continental margin. Geophysical Research Letters, 28(2): 339–342, doi: https://doi.org/10.1029/2000GL012141
Han Xiqiu, Suess E, Huang Yongyang, et al. 2008. Jiulong methane reef: Microbial mediation of seep carbonates in the South China Sea. Marine Geology, 249(3–4): 243–256, doi: https://doi.org/10.1016/j.margeo.2007.11.012
Han Xiqiu, Suess E, Liebetrau V, et al. 2014. Past methane release events and environmental conditions at the upper continental slope of the South China Sea: constraints by seep carbonates. International Journal of Earth Science, 103(7): 1873–1887, doi: https://doi.org/10.1007/s00531-014-1018-5
Hovland M. 2002. On the self-sealing nature of marine seeps. Continental Shelf Research, 22(16): 2387–2394, doi: https://doi.org/10.1016/S0278-4343(02)00063-8
Huang Chiyue, Chien C W, Zhao Meixun, et al. 2006. Geological study of active cold seeps in the syn-collision accretionary prism Kaoping slope off SW Taiwan. Terrestrial, Atmospheric and Oceanic Sciences, 17(4): 679–702, doi: https://doi.org/10.3319/TAO.2006.17.4.679(GH)
Hyndman R D, Spence G D. 1992. A seismic study of methane hydrate marine bottom simulating reflectors. Journal of Geophysical Research: Solid Earth, 97(B5): 6683–6698, doi: https://doi.org/10.1029/92JB00234
Kvenvolden K A. 1993. Gas hydrates-geological perspective and global change. Reviews of Geophysics, 31(2): 173–187, doi: https://doi.org/10.1029/93RG00268
Li Jinfa, Ye Jianliang, Qin Xuwen, et al. 2018. The first offshore natural gas hydrate production test in South China Sea. China Geology, 1(1): 5–16, doi: https://doi.org/10.31035/cg2018003
Li Lun, Lei Xinhua, Zhang Xin, et al. 2013. Gas hydrate and associated free gas in the Dongsha Area of northern South China Sea. Marine and Petroleum Geology, 39(1): 92–101, doi: https://doi.org/10.1016/j.marpetgeo.2012.09.007
Li Niu, Feng Dong, Chen Linying, et al. 2016. Using sediment geochemistry to infer temporal variation of methane flux at a cold seep in the South China Sea. Marine and Petroleum Geology, 1: 835–845, doi: https://doi.org/10.1016/j.marpetgeo.2016.07.026
Liu Bin. 2017. Gas and gas hydrate distribution around seafloor mound in the Dongsha area, north slope of the South China Sea. Haiyang Xuebao (in Chinese), 39(3): 68–75
Liu Boran, Song Haibin, Guan Yongxian, et al. 2015a. Submarine slide and mud volcanism activities in gas hydrate bearing area on the northeastern slope, South China Sea. Haiyang Xuebao (in Chinese), 37(9): 59–70
Liu Boran, Song Haibin, Guan Yongxian, et al. 2015b. Characteristics and formation mechanism of cold seep system in the northeastern continental slope of South China Sea from sub-bottom profiler data. Chinese Journal of Geophysics (in Chinese), 58(1): 247–256
Lu Hongfeng, Liu Jian, Chen Fang, et al. 2005. Mineralogy and stable isotopic composition of authigenic carbonates in bottom sediments in the offshore area of southwest Taiwan, South China Sea: Evidence for gas hydrates occurrence. Earth Science Frontiers (in Chinese), 12(3): 268–276
MacDonald I R, Bender L C, Vardaro M, et al. 2005. Thermal and visual time-series at a seafloor gas hydrate deposit on the Gulf of Mexico slope. Earth and Planetary Science Letters, 233(1–2): 45–59, doi: https://doi.org/10.1016/j.epsl.2005.02.002
MacDonald I R, Guinasso N L Jr., Sassen R, et al. 1994. Gas hydrate that breaches the sea floor on the continental slope of the Gulf of Mexico. Geology, 22(8): 699–702, doi: https://doi.org/10.1130/0091-7613(1994)022<0699:GHTBTS>2.3.CO;2
MacKay M E, Jarrard R D, Westbrook G K, et al. 1994. Origin of bottom-simulating reflectors: Geophysical evidence from the Cascadia accretionary prism. Geology, 22(5): 459–462, doi: https://doi.org/10.1130/0091-7613(1994)022<0459:OOBSRG>2.3.CO;2
Magalhães V H, Pinheiro L M, Ivanov M K, et al. 2012. Formation processes of methane-derived authigenic carbonates from the gulf of Cadiz. Sedimentary Geology, 243–1: 155–168, doi: https://doi.org/10.1016/j.sedgeo.2011.10.013
Mazurenko L L, Soloviev V A, Belenkaya I, et al. 2002. Mud volcano gas hydrates in the gulf of Cadiz. Terra Nova, 14(5): 321–329, doi: https://doi.org/10.1046/j.1365-3121.2002.00428.x
McDonnell S L, Max M D, Cherkis N Z, et al. 2000. Tectono-sedimentary controls on the likelihood of gas hydrate occurrence near Taiwan. Marine and Petroleum Geology, 17(8): 929–936, doi: https://doi.org/10.1016/S0264-8172(00)00023-4
Petersen C J, Papenberg C, Klaeschen D. 2007. Local seismic quantification of gas hydrates and BSR characterization from multi-frequency OBS data at northern Hydrate Ridge. Earth and Planetary Science Letters, 255(3–4): 414–431, doi: https://doi.org/10.1016/j.epsl.2007.01.002
Pinheiro L M, Ivanov M K, Sautkin A, et al. 2003. Mud volcanism in the Gulf of Cadiz: results from the TTR-10 cruise. Marine Geology, 195(1–4): 131–151, doi: https://doi.org/10.1016/S0025-3227(02)00685-0
Plaza-Faverola A, Westbrook G K, Ker S, et al. 2010. Evidence from three-dimensional seismic tomography for a substantial accumulation of gas hydrate in a fluid-escape chimney in the Nyegga pockmark field, offshore Norway. Journal of Geophysical Research: Solid Earth, 115(B8): B08104
Reagan M T, Moridis G J. 2007. Oceanic gas hydrate instability and dissociation under climate change scenarios. Geophysical Research Letters, 34(22): L22709, doi: https://doi.org/10.1029/2007GL031671
Riedel M. 2007. 4D seismic time-lapse monitoring of an active cold vent, northern Cascadia margin. Marine Geophysical Researches, 28(4): 355–371, doi: https://doi.org/10.1007/s11001-007-9037-2
Riedel M, Novosel I, Spence G D, et al. 2006. Geophysical and geochemical signatures associated with gas hydrate-related venting in the northern Cascadia margin. GSA Bulletin, 118(1–2): 23–38, doi: https://doi.org/10.1130/B25720.1
Roberts H H, Hardage B A, Shedd W W, et al. 2006. Seafloor reflectivity—an important seismic property for interpreting fluid/gas expulsion geology and the presence of gas hydrate. The Leading Edge, 25(5): 620–628, doi: https://doi.org/10.1190/1.2202667
Ruppel C D, Kessler J D. 2017. The interaction of climate change and methane hydrates. Reviews of Geophysics, 55(1): 126–168, doi: https://doi.org/10.1002/2016RG000534
Ryu B J, Collett T S, Riedel M, et al. 2013. Scientific results of the Second Gas Hydrate Drilling Expedition in the Ulleung Basin (UBGH2). Marine and Petroleum Geology, 1: 1–20, doi: https://doi.org/10.1016/j.marpetgeo.2013.07.007
Sha Zhibin, Liang Jinqiang, Zhang Guangxue, et al. 2015. A seepage gas hydrate system in northern South China Sea: Seismic and well log interpretations. Marine Geology, 1: 69–78, doi: https://doi.org/10.1016/j.margeo.2015.04.006
Shedd W, Boswell R, Frye M. 2012. Occurrence and nature of “bottom simulating reflectors” in the northern Gulf of Mexico. Marine and Petroleum Geology, 34(1): 31–40, doi: https://doi.org/10.1016/j.mar-petgeo.2011.08.005
Shipley T, Houston M H, Buffler R T, et al. 1979. Seismic evidence for widespread possible gas hydrate horizons on continental slopes and rises. AAPG Bulletin, 63(12): 2204–2213
Shyu C T, Hsu S K, Liu C S. 1998. Heat flows off southwest Taiwan: Measurements over mud diapirs and estimated from bottom simulating reflectors. Terrestrial, Atmospheric and Oceanic Sciences, 9(4): 795–812, doi: https://doi.org/10.3319/TAO.1998.9.4.795(TAI-CRUST)
Suess E. 2014. Marine cold seeps and their manifestations: geological control, biogeochemical criteria and environmental conditions. International Journal of Earth Sciences, 103(7): 1889–1916, doi: https://doi.org/10.1007/s00531-014-1010-0
Suess E, Torres M E, Bohrmann G, et al. 2001. Sea floor methane hydrates at Hydrate Ridge, Cascadia. In: Paull C K, Dillon W P, eds. Natural Gas Hydrates: Occurrence, Distribution, and Detection. American: AGU, 87–98
Tong Hongpeng, Feng Dong, Cheng Hai, et al. 2013. Authigenic carbonates from seeps on the northern continental slope of the South China Sea: New insights into fluid sources and geo-chronology. Marine and Petroleum Geology, 1: 260–271, doi: https://doi.org/10.1016/j.marpetgeo.2013.01.011
Vanneste M, Sultan N, Garziglia S, et al. 2014. Seafloor instabilities and sediment deformation processes: The need for integrated, multi-disciplinary investigations. Marine Geology, 1: 183–214, doi: https://doi.org/10.1016/j.margeo.2014.01.005
Wang Jiliang, Jaiswal P, Haines S S, et al. 2018a. Gas hydrate quantification using full-waveform inversion of sparse ocean-bottom seismic data: A case study from Green Canyon Block 955, Gulf of Mexico. Geophysics, 83(4): B167–B181, doi: https://doi.org/10.1190/geo2017-0414.1
Wang Jiliang, Sain K, Wang Xiujuan, et al. 2014a. Characteristics of bottom-simulating reflectors for Hydrate-filled fractured sediments in Krishna-Godavari Basin, eastern Indian margin. Journal of Petroleum Science and Engineering, 1: 515–523, doi: https://doi.org/10.1016/j.petrol.2014.08.014
Wang Jiliang, Wu Shiguo, Kong Xiu, et al. 2018b. Subsurface fluid flow at an active cold seep area in the Qiongdongnan Basin, northern South China Sea. Journal of Asian Earth Sciences, 1: 17–26, doi: https://doi.org/10.1016/j.jseaes.2018.06.001
Wang Jiliang, Wu Shiguo, Yao Yongjian. 2018c. Quantifying gas hydrate from microbial methane in the South China Sea. Journal of Asian Earth Sciences, 1: 48–56, doi: https://doi.org/10.1016/j.jseaes.2018.01.020
Wang Shuhong, Yan Wen, Magalhäes V H, et al. 2012. Calcium isotope fractionation and its controlling factors over authigenic carbonates in the cold seeps of the northern South China Sea. Chinese Science Bulletin, 57(11): 1325–1332, doi: https://doi.org/10.1007/s11434-012-4990-9
Wang Shuhong, Yan Wen, Magalhães V H, et al. 2014b. Factors influencing methane-derived authigenic carbonate formation at cold seep from southwestern Dongsha area in the northern South China Sea. Environmental Earth Sciences, 71(5): 2087–2094, doi: https://doi.org/10.1007/s12665-013-2611-9
Wang Xiujuan, Liu Bo, Qian Jin, et al. 2018d. Geophysical evidence for gas hydrate accumulation related to methane seepage in the Taixinan Basin, South China Sea. Journal of Asian Earth Sciences, 1: 27–37, doi: https://doi.org/10.1016/j.jseaes.2017.11.011
Wenau S, Spiess V, Pape T, et al. 2015. Cold seeps at the salt front in the lower Congo Basin I: Current methane accumulation and active seepage. Marine and Petroleum Geology, 1: 894–908, doi: https://doi.org/10.1016/j.marpetgeo.2014.07.032
Wu Lushan, Yang Shengxiong, Liang Jinqiang, et al. 2013. Variations of pore water sulfate gradients in sediments as indicator for underlying gas hydrate in Shenhu Area, the South China Sea. Science China Earth Sciences, 56(4): 530–540, doi: https://doi.org/10.1007/s11430-012-4545-6
Yan Pin, Deng Hui, Liu Hailing. 2006. The geological structure and prospect of gas hydrate over the Dongsha Slope, South China Sea. Terrestrial, Atmospheric and Oceanic Sciences, 17(4): 645–658, doi: https://doi.org/10.3319/TAO.2006.17.4.645(GH)
Yang Shengxiong, Zhang Ming, Liang Jinqiang, et al. 2015. Preliminary results of China’s third gas hydrate drilling expedition: A critical step from discovery to development in the South China Sea. Fire in the Ice: Methane Hydrate Newsletter, 15(2): 1–5
Zhang Guangxue, Yang Shengxiong, Zhang Ming, et al. 2014. GMGS2 expedition investigates rich and complex gas hydrate environment in the South China Sea. Fire in the Ice: Methane Hydrate Newsletter, 14(1): 1–5
Zhang Haiqi, Yang Shengxiong, Wu Nengyou, et al. 2007. China’s first gas hydrate expedition successful. Fire in the Ice: Methane Hydrate Newsletter, 7(2): 1
Zhuang Chang, Chen Fang, Cheng Sihai, et al. 2016. Light carbon isotope events of foraminifera attributed to methane release from gas hydrates on the continental slope, northeastern South China Sea. Science China Earth Sciences, 59(10): 1981–1995, doi: https://doi.org/10.1007/s11430-016-5323-7
Acknowledgements
We thank Guangzhou Marine Geological Survey for their permission to release the geophysical data. Luis M. Pinheiro thanks FCT/MCTES for the financial support to CESAM (UID/AMB/50 017 /2019), through national funds. Thanks to the two anonymous reviewers for their constructive comments.
Author information
Authors and Affiliations
Corresponding author
Additional information
Foundation item: The Laboratory for Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology under contract No. MMRKF201810; the National Key Research & Development Program of China under contract Nos 2018YFC0310000 and 2017YFC0307406; the Shandong Province “Taishan Scholar” Construction Project.
Rights and permissions
About this article
Cite this article
Liu, B., Chen, J., Pinheiro, L.M. et al. An insight into shallow gas hydrates in the Dongsha area, South China Sea. Acta Oceanol. Sin. 40, 136–146 (2021). https://doi.org/10.1007/s13131-021-1758-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13131-021-1758-6