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The formation of explosive volcanos at the circum-Pacific convergent margin during the last century

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Journal of Oceanology and Limnology 2023年第1期41卷 75-83页

作者： Fanfan TIAN Kun WANG Guozhi XIE Weidong SUN Center of Deep Sea Research Center of Ocean Mega ScienceInstitute of OceanologyChinese Academy of SciencesQingdao 266071China deep-sea Multidisciplinary research center Laoshan LaboratoryQingdao 266237China University of Chinese Academy of Sciences Beijing 100049China

The circum-Pacific convergent margin is known as"the Ring of Fire",with abundant volcano eruptions.Large eruptions are rare but very disastrous.It remains obscure how are large explosive volcanos formed and where are the danger zones.Three largest eruptions since 1900,the Hunga Tonga-Hunga Ha’apai,the Mt.Pinatubo,and the Novarupta were found to be associated with subductions of volatile-rich sediments and located close to slab windows.Among them,the Hunga Tonga-Hunga Ha’apai is close to subducting seamount chains;the Mt.Pinatubo is right next to subducting fossil ridges.Both seamount chains and fossil ridges have water depths much shallower than the carbonate compensation depths(CCD)in the Pacific Ocean.Seismic image shows that a seamount is subducting towards the Novarupta volcano.Subduction of volatile-rich sediments and a slab window nearby are the two most important favorable conditions for catastrophic eruptions.Slab windows expose the mantle wedge to the hot asthenosphere,which increases the temperature and dramatically promotes the partial melting of the carbonate-fluxed domains,forming volatile-rich magmas that powered explosive eruptions.

关键词： large explosive volcanos subducting seamount chains volatile-rich sediments slab windows Tonga

Target Deployment and Retrieval Using JIAOLONG Manned Submersible in the Depth of 6600 m in Mariana Trench

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China Ocean Engineering 2017年第5期31卷 618-623页

作者： GAO Xiang DING Kang REN Yu-gang FU Wen-tao DING Zhong-jun ZHAO Sheng-ya LIU Bao-hua National deep sea center Institute of deep-sea Science and Engineering Chinese Academy of Sciences

China＇s 7000 m manned submersible JIAOLONG carried out an exploration cruise at the Mariana Trench from June to July 2016. The submersible completed nine manned dives on the north and south area of the Mariana Trench from the depth of 5500 to 6700 m, to investigate the geological, biological and chemical characteristics in the hadal area. During the cruise, JIAOLONG deployed a gas-tight serial sampler to collect the water near the sea bottom regularly. Five days later, the sub located the sampler in another dive and retrieved it successfully from the same location, which is the first time that scientists and engineers finished the high accuracy in-situ deployment and retrieval using a manned submersible with Ultra-Short Base Line （USBL） positioning system at the depth more than 6600 m. In this task, we used not only the USBL system of the manned submersible but also a compound strategy, including five position marks, the sea floor terrain, the depth contour, and the heading of the sub. This paper introduces the compound strategy of the target deployment and retrieval with the practical diving experience of JIAOLONG, and provides a promising technique for other underwater vehicles such as manned submersible or Remote Operated Vehicle （ROV） under similar conditions.

关键词： target deployment and retrieval manned submersible USBL Mariana Trench

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冥古代蛇纹石化过程合成氨

Science Bulletin 2023年第11期68卷 1109-1112,M0003页

作者：商修齐黄瑞芳孙卫东 center of deep-sea research Institute of OceanologyChinese Academy of SciencesQingdao 266071China deep-sea Multidisciplinary research center Laoshan LaboratoryQingdao 266237China University of Chinese Academy of Sciences Beijing 100049China SUSTech Academy for Advanced Interdisciplinary Studies Southern University of Science and TechnologyShenzhen 518055China

著名的Miller-Urey实验证明甲烷、氨气(NH3)、水蒸气和氢气在电火花下可以产生大量氨基酸,这一实验被认为是生命起源最重要的前置反应之一.然而,传统认为冥古代时期地球大气的初始成分主要包括二氧化碳和氮气(N2),在这样的中性大气里氨... 详细信息

著名的Miller-Urey实验证明甲烷、氨气(NH3)、水蒸气和氢气在电火花下可以产生大量氨基酸,这一实验被认为是生命起源最重要的前置反应之一.然而,传统认为冥古代时期地球大气的初始成分主要包括二氧化碳和氮气(N2),在这样的中性大气里氨基酸合成的效率将大大降低,氨基酸能否在早期大气中大量合成仍然存在争议.为解决这一难题,我们进行了“橄榄岩十水+氮气(+二氧化碳)”的高温高压实验.实验结果证明氮气参与蛇纹石化过程,产生氨基酸合成的关键原料——氨.考虑到蛇纹石化过程中同样可以产生大量甲烷,在冥古代地表广泛的蛇纹石化作用下,原始大气的成分将会从以二氧化碳和氮气为主演化为以甲烷和氨气为主,为大气中氨基酸的合成创造了适宜条件.

关键词：蛇纹石化地球大气二氧化碳氨基酸合成生命起源橄榄岩冥古代实验证明

Investigation on strong nonlinear interactions between underwater explosion and water surface based on compressible multiphase flow with phase transition

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Journal of Hydrodynamics 2023年第2期35卷 351-364页

作者： Jun Yu Hai-kun Wang Zhen-xin Sheng Yi Hao China Ship Scientific research center Wuxi214082China Taihu Laboratory of deep-sea Technological Science Wuxi214082China

The strong nonlinear interactions between underwater explosion and water surface were numerically investigated using a phase transition model based on a four-equation system,which can deal with the complex deformable interface among different phases,including water,air,explosion bubble,and cavitation.The numerical method is verified by comparing the numerical results with experimental results,and good agreements are found.This study considers an ideal sine wave for simulating the shape of water surface.Two examples of different detonation depths of charge are investigated.In each example,the first case is the basic simulation without surface wave,and the other three cases are the simulations with sine waves of different wavelengths.Unique characteristics of the interactions,such as shock wave propagation,explosion bubble expansion,and the generation,development,and collapse of cavitation,are observed in the numerical simulations.By capturing the detailed density and pressure contours during the interaction process,we can better understand the underlying mechanisms of the explosion bubble,cavitation,and surface waves.These numerical results demonstrate that geometric nonlinearity impacts cavitation evolution and the explosion bubble movement mechanism.Additionally,the secondary cavitation phenomenon has been found in the cases without surface wave,and its fundamental physical mechanism is presented in detail.The present results can expand the existing database of multiphase flow in the underwater explosion and provide an insight into the strong nonlinear interaction between the underwater explosion and water surface.

关键词： Underwater explosion compressible multiphase flow phase transition model cavitation water surface

俯冲带洋底玄武岩在晚更新世的风化与碳酸盐化

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Science Bulletin 2023年第22期68卷 2721-2723,M0005页

作者：王茂宇李贺杨昕瑜孙卫东陈天宇 State Key Laboratory for Mineral Deposits research Frontiers Science Center for Critical Earth Material CyclingSchool of Earth Sciences and EngineeringNanjing UniversityNanjing 210023China Center of Deep Sea Research Ocean Mega-Science CenterInstitute of OceanologyChinese Academy of SciencesQingdao 266071China deep-sea Multidisciplinary research center Laoshan LaboratoryQingdao 266237China University of Chinese Academy of Sciences Beijing 100049China

海底玄武岩风化及碳酸盐化是海洋的重要碳汇,调节了海洋和大气系统的碳循环.以往一般认为这一过程仅发生在年轻洋壳中,对俯冲带洋底玄武岩的风化和碳酸盐化几乎没有关注.本研究基于西太平洋Mussau海沟东侧崖壁的玄武岩样品,利用激光剥... 详细信息

海底玄武岩风化及碳酸盐化是海洋的重要碳汇,调节了海洋和大气系统的碳循环.以往一般认为这一过程仅发生在年轻洋壳中,对俯冲带洋底玄武岩的风化和碳酸盐化几乎没有关注.本研究基于西太平洋Mussau海沟东侧崖壁的玄武岩样品,利用激光剥蚀原位铀系不平衡法对洋底玄武岩中的碳酸盐脉进行定年,发现其形成于(102±16)ka和(132±21)ka.通过矿物学、微形貌与稳定同位素手段,确认了碳酸盐脉的矿物相为方解石,并以侵染状分布于玄武岩中,无生物碳酸盐的形态,并沉淀于冷水环境中.这些证据综合表明碳酸盐脉很可能是玄武岩在海底风化,释放出碳酸氢根,局部方解石过饱和沉淀而成.该结果表明古老玄武岩在俯冲带的化学风化和碳酸盐化依然活跃,未来需进一步系统研究俯冲带的玄武岩风化通量.

关键词：碳酸盐化俯冲带稳定同位素化学风化洋底西太平洋晚更新世大气系统

Characterization of subduction initiation

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Journal of Oceanology and Limnology 2023年第1期41卷 72-74页

作者： Weidong SUN Lipeng ZHANG Center of Deep Sea Research Institute of OceanologyCenter for Ocean Mega-ScienceChinese Academy of SciencesQingdao 266071China deep-sea Multidisciplinary research center Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China School of Marine Sciences University of Chinese Academy of SciencesBeing 100049China

Compression is required for all kinds of subduction initiations,which may cause either subsidence or uplift,depending on the ages of the oceanic plates.Subduction initiations associated with the old oceanic crust tend to amplify preexisting subsidence by compression,whereas those associated with young oceanic plates may result in uplift.

关键词： subduction initiation induced and spontaneous west Pacific plate tectonics

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冥古代蛇纹石化过程合成氨（英文）

Science Bulletin 2023年第11期 1109-1112页

作者：商修齐黄瑞芳孙卫东 center of deep-sea research Institute of Oceanology Chinese Academy of Sciences deep-sea Multidisciplinary research center Laoshan Laboratory University of Chinese Academy of Sciences SUSTech Academy for Advanced Interdisciplinary Studies Southern University of Science and Technology

著名的Miller-Urey实验证明甲烷、氨气(NH3)、水蒸气和氢气在电火花下可以产生大量氨基酸,这一实验被认为是生命起源最重要的前置反应之一.然而,传统认为冥古代时期地球大气的初始成分主要包括二氧化碳和氮气(N2),在这样的中性大气里氨...

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research status of distinct element method particle flow analysis method and its application in deep sea core drilling

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Research status of distinct element method particle flow ana...

Coupling between the Cenozoic west Pacific subduction initiation and decreases of atmospheric carbon dioxides

作者： Yugang Ren Kaiben Yu Sen Zheng Lei Yang Haibin Qi Jianhua Zhang Yanjun Liu School of Mechanical Engineering Shandong University National deep sea center Science and Technology on Underwater Vehicle Laboratory Harbin Engineering University

Discrete element particle flow method（DEM） is a numerical simulation method aimed at the discontinuity,non-uniformity and non-linear mechanical properties of rock mass.It analyzes the damage and fracture mechanism of materials and structures from the perspective of micromechanics.It has been widely applied in different disciplines and engineering fields.This paper firstly introduces the basic principle of discrete element particle method and its calculation theory,the second review conducted extensive research,the method of this paper expounds in detail the progress at home and abroad,and analyses the application in the field of rock drilling medium,the final mechanical properties of the deep core drilling analysis apply to imagine thinking and research.

关键词： DEM Micromechanics Core sampling drill Technical application development

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Acta Geochimica 2023年第3期42卷 387-392页

作者： Guozhi Xie Fanfan Tian Kun Wang Yuanyuan Xiao Tianyu Chen Weidong Sun Center of Deep Sea Research Institute of OceanologyChinese Academy of SciencesQingdao 266071China deep-sea Multidisciplinary research center Laoshan LaboratoryQingdao 266237China University of Chinese Academy of Sciences Beijing 100049China CAS Key Laboratory of Marine Geology and Environment Ocean Mega-Science CenterInstitute of OceanologyChinese Academy of SciencesQingdao 266071China State Key Lab Mineral Deposits research School of Earth Science and EngineerNanjing UniversityNanjing 210023China

At the beginning of the Cenozoic,the atmospheric CO_(2)concentration increased rapidly from~2000 ppmv at 60 Ma to~4600 ppmv at 51 Ma,which is 5–10 times higher than the present value,and then continuous declined from~51 to 34 Ma.The cause of this phenomenon is still not well understood.In this study,we demonstrate that the initiation of Cenozoic west Pacific plate subduction,triggered by the hard collision in the Tibetan Plateau,occurred at approximately 51 Ma,coinciding with the tipping point.The water depths of the Pacific subduction zones are mostly below the carbonate compensation depths,while those of the Neo-Tethys were much shallower before the collision and caused far more carbonate subducting.Additionally,more volcanic ashes erupted from the west Pacific subduction zones,which consume CO_(2).The average annual west Pacific volvano eruption is 1.11 km~3,which is higher than previous estimations.The amount of annual CO_(2)absorbed by chemical weathering of additional west Pacific volcanic ashes could be comparable to the silicate weathering by the global river.We propose that the initiation of the western Pacific subduction controlled the long-term reduction of atmospheric CO_(2)concentration.

关键词： Subduction initiation in the west Pacific Collision of the Neo-Tethys Volcano eruption rates Cenozoic CO_(2)declining Carbonate compensation depths Chemical weathering