ZHOU Sheng,
SONG Gang,
HUANG Long et al
.2017.Marine towed transient electromagnetic system working in deep-sea below 6000 meters and its application.Chinese Journal Of Geophysics,60(11): 4294-4301,doi: 10.6038/cjg20171117
Abstract：Aiming at the requirements of fast, effective and convenient detection of the hydrothermal sulfide ore in the contract area of the Southwest Indian Ocean, we have developed a towed transient electromagnetic system working in deep-sea below 6000 meters. The system consists of deck control system, ten thousand meters photoelectric composite cable, instrument cabin and antenna cabin. To release towed body conveniently and find anomaly response quickly, coincident loop is applied. Theoretical numerical calculation results show that the abnormal response of the near seafloor hydrothermal sulfide deposit appears during the delay time of 1~100 ms when the towed height is no larger than 50m. In addition, the influence of the towing depth on the transient electromagnetic field and the performance of the instrument are studied by experiments. Finally, anomaly response of a typical hydrothermal sulfide ore was found by using this system, in the hydrothermal area of the southwest Indian Ocean Ridge, and in the second leg of China's 30th ocean exploration voyage.
Baker E T, German C R. 2004. On the global distribution of mid-ocean ridge hydrothermal vent-fields.//German C R, Lin J, Parson L M. Mid-Ocean Ridges: Hydrothermal Interactions between the Lithosphere and Oceans. Washington DC, USA: American Geophysical Union, 245-266. Cheesman S J, Edwards R N, Chave A D. 1987. On the theory of sea-floor conductivity mapping using transient electromagnetic systems. Geophysics, 52(2): 204-217. Constable S. 2010. Ten years of marine CSEM for hydrocarbon exploration. Geophysics, 75(5): 75A67-75A81. Edwards R. 2005. Marine controlled source electromagnetics: principles, methodologies, future commercial applications. Surveys in Geophysics, 26(6): 675-700. Evans R L, Everett M E. 1994. Discrimination of hydrothermal mound structures using transient electromagnetic methods. Geophysical Research Letters, 21(6): 501-504. Holten T, Flekkøy E G, Singer B, et al. 2009. Vertical source, vertical receiver, electromagnetic technique for offshore hydrocarbon exploration. First Break, 27(5): 89-93. Imamura N, Goto T, Takekawa J, et al. 2012. Full time-domain waveform inversion of controlled-source electromagnetic exploration of submarine massive sulphides.//2012 SEG Annual Meeting. Las Vegas, Nevada: Society of Exploration Geophysicists, 1-6. Krivochieva S, Chouteau M. 2002. Whole-space modeling of a layered earth in time-domain electromagnetic measurements. Journal of Applied Geophysics, 50(4): 375-391. Li H. 2007. Theoretical calculation of marine transient electromagnetic response and research of shallow sea-floor detection technology [Ph. D. Thesis] (in Chinese). Jilin: Jilin University, 1-140. Liu C S, Lin J. 2006. Transient electromagnetic response modeling of magnetic source on seafloor and the analysis of seawater effect. Chinese Journal of Geophysics (in Chinese), 49(6): 1891-1898, doi: 10.3321/j.issn:0001-5733.2006.06.039. Liu C S, Lin J, Zhou F D. 2010. Transient response characteristics of central loop configuration on seafloor. Chinese Journal of Radio Science (in Chinese), 25(1): 195-200. Nabighian M N. 1992. Electromagnetic Methods in Applied Geophysics: Volume 1, Theory. Translated by Zhao J X, Wang Y J. Beijing: Geological Publishing House, 120-240. Nakayama K, Shingyouji T, Mottori M, et al. 2011. Marine Time-domain electromagnetic technologies for the ocean bottom mineral resources.//Proceedings of the 10th SEGJ International Symposium. Kyoto, Japan, 1-4. Nakayama K, Saito A. 2014. Development of new marine TDEM systems for the ocean bottom hydrothermal deposits.//SEG Technical Program Expanded Abstracts 2014. SEG, 850-854. Nautilus Minerals Co. 2012. Mineral Resource Estimate: Solwara Project, Bismarck Sea, PNG, http://www.nautilusminerals.com/irm/PDF/1055_0/Solwara1Project BismarckSea Mineral ResourceEstimate. Swidinsky A, Hölz S, Jegen M. 2012. On mapping seafloor mineral deposits with central loop transient electromagnetics. Geophysics, 77(3): E171-E184. Tao C H, Li H M, Jin X B, et al. 2014. Seafloor hydrothermal activity and polymetallic sulfide exploration on the southwest Indian ridge. Chinese Science Bulletin, 59(19): 2266-2276. Wang Y X, Wang J L, Wang J Y, et al. 1998. The research of conductivity on sea-floor by transient electromagnetic system. Acta Geophysica Sinica (in Chinese), 41(6): 841-847. Zhou F D, Lin J, Liu C S, et al. 2006. Frequency characteristic of receiver coil in shallow seafloor transient electromagnetic sounding system——The Influence of bandwidth on the low subsurface resolving power. Progress in Geophysics (in Chinese), 21(4): 1342-1345, doi: 10.3969/j.issn.1004-2903.2006.04.047. Zhou F D, Lin J, Liu C S, et al. 2012. Influence of the turn-off time with central loop device on its marine electromagnetic response. Chinese Journal of Radio Science (in Chinese), 27(1): 203-207. Zhou S, Xi Z Z, Song G, et al. 2012. Responses of the towed transient electromagnetic sounding on deep seafloor. Journal of Central South University (Science and Technology) (in Chinese), 43(2): 605-610. 李慧. 2007. 海洋瞬变响应理论计算及浅海底瞬变电磁探测技术研究[博士论文]. 长春: 吉林大学, 1-140. 刘长胜, 林君. 2006. 海底表面磁源瞬变响应建模及海水影响分析. 地球物理学报, 49(6): 1891-1898, doi: 10.3321/j.issn:0001-5733.2006.06.039. 刘长胜, 林君, 周逢道. 2010. 中心回线装置在海底的瞬变响应特征研究. 电波科学学报, 25(1): 195-200. 王一新, 王家林, 王家映等. 1998. 瞬变电磁系统探测海底电导率的研究. 地球物理学报, 41(6): 841-847. 周逢道, 林君, 刘长胜等. 2006. 浅海底瞬变电磁法接收天线频率特性研究——带宽对浅层分辨的影响. 地球物理学进展, 21(4): 1342-1345, doi: 10.3969/j.issn.1004-2903.2006.04.047. 周逢道, 林君, 刘长胜等. 2012. 中心回线关断时间对海洋电磁响应影响研究. 电波科学学报, 27(1): 203-207. 周胜, 席振铢, 宋刚等. 2012. 深海拖曳式瞬变电磁的响应规律. 中南大学学报(自然科学版), 43(2): 605-610.
| 
