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Journal of Ocean University of China 2020年第2期19卷 377-385页

作者： ZHANG Xia ZHAI Shikui YU Zenghui Key Laboratory of submarine geosciences and prospecting techniques Ministry of Education College of Marine Geosciences Ocean University of China

Hydrothermal barite is a typical low-temperature mineral formed during the mixing of hydrothermal fluid and *** of its extremely low solubility,barite behaves as a close system after crystallization and preserves the geochemical fingerprint of hydrothermal *** this study,the elemental contents and Sr isotope compositions of hydrothermal barites from the Yonaguni IV were determined using electron microprobe and LA-MC-ICP-MS *** these bases,the fluid/sediment interaction during the hydrothermal circulation and physicochemical condition of barite crystallization were *** show that the 87 Sr/86 Sr values of hydrothermal barites from the Yonaguni IV are apparently higher than those of the seawater and associated volcanic rocks,indicating the sufficient interaction between the hydrothermal fluid and overlying *** Sr abundance shows large variations,reflecting the changes in barite growth rate during the fluid *** mineralization condition in the Yonaguni IV was *** the crystallization of barite,hydrothermal fluid and seawater mixed in varying degrees,with the pro-portions of hydrothermal fluid varied from 36%to 72%.The calculated crystallization temperatures range from 109 to 220℃.Sediment plays a critical role during the mineralization process in the Yonaguni IV and incorporation of sediment component into hydrothermal system was prior to barite crystallization and sulfide mineralization.

关键词： strontium isotope hydrothermal barite fluid/sediment interaction crystallization condition Okinawa Trough

Velocity Modeling and Inversion techniques for Locating Microseismic Events in Unconventional Reservoirs

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Journal of Earth Science 2015年第4期26卷 495-501页

作者： Jianzhong Zhang Han Liu Zhihui Zou Zhonglai Huang College of Marine geosciences Ocean University of China Key Laboratory of submarine geosciences and prospecting techniques Ministry of Education

A velocity model is an important factor influencing microseismic event locations. We re- view the velocity modeling and inversion techniques for locating microseismic events in exploration for unconventional oil and gas reservoirs. We first describe the geological and geophysical characteristics of reservoir formations related to hydraulic fracturing in heterogeneity, anisotropy, and variability, then discuss the influences of velocity estimation, anisotropy model, and their time-lapse changes on the accuracy in determining microseismic event locations, and then survey some typical methods for building velocity models in locating event locations. We conclude that the three tangled physical attributes of reservoirs make microseismic monitoring very challenging. The uncertainties in velocity model and ignoring its anisotropies and its variations in hydraulic fracturing can cause systematic mislocations of microseismie events which are unacceptable in microseismic monitoring. So, we propose some potential ways for building accurate velocity models.

关键词： microseismic location velocity model building velocity error anisotropy unconventional reservoir.

A Layer-Stripping Method for 3D Near-Surface Velocity Model Building Using Seismic First-Arrival Times

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Journal of Earth Science 2015年第4期26卷 502-507页

作者： Taikun Shi Jianzhong Zhang Zhonglai Huang Changkun Jin College of Marine geosciences Ocean University of China Key Laboratory of submarine geosciences and prospecting techniques Ministry of Education

In order to improve the efficiency of 3D near-surface velocity model building, we develop a layer-stripping method using seismic first-arrival times. The velocity model within a Common Mid-Point （CMP） gather is assumed to be stratified into thin layers, and the velocity of each layer var- ies linearly with depth. The thickness and velocity of the top layer are estimated using minimum-offset first-arrival data in a CMP gather. Then the top layer is stripped and the second layer becomes a new top layer. After removing the effect of the top layer from the former first-arrival data, the new first-arrival data are obtained and then used to estimate the parameters of the second layer. In this manner, the velocity model, being regarded as that at a CMP location, is built layer-by-layer from the top to the bottom. A 3D near-surface velocity model is then formed using the velocity models at all CMP locations. The tests on synthetic and observed seismic data show that the layer-stripping method can be used to build good near-surface velocity models for static correction, and its computation speed is approximately hundred times faster than that of grid tomography.

关键词： first-arrival time layer-stripping near-surface velocity model building static correction.

Heavy metals in suspended matters during a tidal cycle in the turbidity maximum around the Changjiang(Yangtze) Estuary

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Acta Oceanologica Sinica 2015年第10期34卷 36-45页

作者： ZHANG Huaijing ZHAI Shikui ZHANG Aibin ZHOU Yonghua YU Zenghui College of Marine geosciences Ocean University of China Key Laboratory of submarine geosciences and prospecting techniques Ministry of Education Qingdao Huanhai Marine Engineering prospecting Institute

In order to discuss the content distributions and fluxes of heavy metals in suspended matters during a tidal cycle in the turbidity maximum around the Changjiang （Yangtze） Estuary, the contents of heavy metals （Zn, Pb, Cd, Co and Ni） have been analyzed. During a tidal cycle, the average contents of heavy metals are in the order of Zn〉Ni〉Pb〉Co〉〉Cd. The average contents in ebb tide are generally higher than that in flood tide. However, at the inshore Sta. 11, influenced by the contamination from the nearby waste treatment plant, the average contents of Zn and Ni in flood tide are higher than those in ebb fide and at the offshore Sta. 10, the content of Cd in flood tide higher than that in ebb tide due to marine-derived materials. The five heavy metals, mainly terrigenous, are transported towards east-northeast, and settle down with suspended matters in the area between Sta. 11 and Sta. 10. Influenced by marine-derived materials, the flux value of Cd does not alter significantly with obviously changing in flux direction towards northwest. The source of heavy metals, the salinity of water and the concentration of suspended matters are the main factors controlling the content distributions of heavy metals during a tidal cycle. There is a positive correlation between the contents of heavy metals （Zn, Pb, Co and Ni） and the salinity of water, while the opposite correlation between the contents and the concentrations of suspended matters. Because of marine-derived materials, the content of Cd is not correlated with the concentration of suspended matters and the salinity of water.

关键词： Changjiang (Yangtze) Estuary turbidity maximum zone tidal cycle suspended matters content ofheavy metal flux of heavy metal

Effects of Uncertainties in the Position and Orientation of Both the Transmitter and Receivers on Marine Controlled-Source Electromagnetic Data

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Journal of Ocean University of China 2016年第1期15卷 83-92页

作者： XU Zhenhuan LIU Ying LI Yuguo Key Laboratory of submarine geosciences and prospecting techniques of Ministry of Education Ocean University of China

Simulation and interpretation of marine controlled-source electromagnetic(CSEM) data often approximate the transmitter source as an ideal horizontal electric dipole(HED) and assume that the receivers are located on a flat ***,however,the transmitter dipole source will be rotated,tilted and deviated from the survey profile due to ocean *** free-fall receivers may be also rotated to some arbitrary horizontal orientation and located on sloping *** this paper,we investigate the effects of uncertainties in the transmitter tilt,transmitter rotation and transmitter deviation from the survey profile as well as in the receiver's location and orientation on marine CSEM *** model study shows that the uncertainties of all position and orientation parameters of both the transmitter and receivers can propagate into observed data uncertainties,but to a different *** interpreting marine data,field data uncertainties caused by the position and orientation uncertainties of both the transmitter and receivers need to be taken into account.

关键词： electromagnetic uncertainty in position and orientations data certainty marine CSEM

Shallow Water Body Data Processing Based on the Seismic Oceanography

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Journal of Ocean University of China 2013年第3期12卷 319-326页

作者： LIU Huaishan HU Yi YIN Yanxin WANG Linfei TONG Siyou MA Hai Key Laboratory of submarine geosciences and prospecting techniques Ministry of EducationOcean University of China

Physical properties of sea water,such as salinity,temperature,density and acoustic velocity,could be demarcated through degradation of energy caused by water absorption,attenuation and other *** overcome the challenging difficulties in the quick monitoring of these physical properties,we have explored the high resolution marine seismic survey to instantly characterize *** on the unique wavefield propagating in the sea water,we have developed a new approach to suppress the noise caused by the shallow sea water disturbance and obtain useful information for estimating the sea water *** approach improves seismic data with high signal-to-noise ratio and *** seismic reflection imaging can map the sea water structure *** with the knowledge of local water body structure profile over years,the instant model for predicting the sea water properties could be built using the seismic data acquired from the specially designed high precision marine seismic *** model can also be updated with instant observation and the complete data processing *** present study has the potential value to many applications,such as 3D sea water monitoring,engineering evaluation,geological disaster assessment and environmental assessment.

关键词： seismic oceanography seismic exploration seismic reflection profiling marine water body characteristics rapidmonitoring

Adaptive Finite Element Modeling of Marine Controlled-Source Electromagnetic Fields in Two-Dimensional General Anisotropic Media

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Journal of Ocean University of China 2013年第1期12卷 1-5页

作者： LI Yuguo LUO Ming PEI Jianxin Key Lab of submarine geosciences and prospecting techniques of Ministry of Education Ocean University of China

In this paper, we extend the scope of numerical simulations of marine controlled-source electromagnetic (CSEM) fields in a particular case of anisotropy (dipping anisotropy) to the general case of anisotropy by using an adaptive finite element approach. In comparison to a dipping anisotropy case, the first order spatial derivatives of the strike-parallel components arise in the partial differential equations for generally anisotropic media, which cause a non-symmetric linear system of equations for finite element modeling. The adaptive finite element method is employed to obtain numerical solutions on a sequence of refined unstructured triangular meshes, which allows for arbitrary model geometries including bathymetry and dipping layers. Numerical results of a 2D anisotropic model show both anisotropy strike and dipping angles have great influence on the marine CSEM responses.

关键词： adaptive finite elements marine CSEM general anisotropy

Response of the distributary channel of the Huanghe River estuary to water and sediment discharge regulation in 2007

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Chinese Journal of Oceanology and Limnology 2010年第6期28卷 1362-1370页

作者：马妍妍李广雪叶思源张志恒赵广明李景阳周春艳丁文洁杨欣 College of Marine geosciences Ocean University of China Key Lab of submarine geosciences and prospecting techniques Ministry of Education Qingdao Institute of Marine Geology

The water and sediment discharge regulation （WSDR） project, which has been performed since 2002 before flood season every year, is of great significance to the river management in China. Until 2007, six experiments have been fulfilled to evaluate the effect of the project on the natural environment. To fill the gap of investigations, a study on flood and suspended sediment transportation and channel changing along the distributary channel of the Huanghe （Yellow） River was conducted during the WSDR project period in 2007. The lower channel was scoured rapidly and the channel became unobstructed gradually several days after the flood peak water was discharged from the Xiaolangdi Reservoir. Within four days after the flood peak at 3 000 m3/s entered the distributary, the channel in the river mouth area was eroded quickly. Both the mean values of area and depth of the main channel were tripled, and the maximum flood carrying capacity increased to 5 500 m3/s or more. Then, the river channel was silted anew in a very short time after completion of the WSDR. Favored by the WSDR project, the fiver status in April 2008 became better than that of the year before. The adjustment ranges of main channel parameters were about 30%, 10%, and 10% at sections C2, Q4, and Q7, respectively. The process of rapid erosion-deposition was more active 15 km away in the channel from the fiver mouth due to the marine influence. It is reasonable for discharging sediment at concentration peak from Xiaolangdi Reservoir at the end of the flood peak. As a result, the sediment peak reached the river mouth about two days later than that of the water current. In addition, the WSDR project has improved the development of the estuarine wetland. Wetland vegetation planted along the river banks restrained the water flow as a strainer and improved the main channel stability. It is suggested to draw water at mean rate of 150 m3/s from the Huanghe River during flood periods, because at the rate the water in

关键词： Huanghe (Yellow) River estuary water and sediment regulation river channel adjustment wetland.

Evolution history and trend of the modern Huanghe River Delta

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Acta Oceanologica Sinica 2010年第2期29卷 40-52页

作者： MA Yanyan LI Guangxue College of Marine geosciences Ocean University of China Qingdao 266100 China Key Laboratory of submarine geosciences and prospecting techniques of Ministry of Education Qingdao 266100 China

The evolvement history of modern Huanghe River Delta tidal flat, coastline and underwater terrain were studied based on the analysis of remote sensing images and water depth data. Based on the analysis of seafloor terrain evolution on different historical stages, a formula simulating the erosion and deposition evolvement model of subaqueous Huanghe River Delta slope was proposed, and the evolvement trend of the subaqueous delta terrain was predicted. The result shows that the equilibrium transition zone is near the water depth of 12 m with seabed erosion in shallower water and accumulation in deeper water during the first 150 a after the river channel was deserted. In the meantime, the underwater slope became gentler and the coastal erosion rate became slow gradually. Then, the subaqueous delta slope changed to up concave from upper convex, and the shape of subaqueous delta disappeared. The coast type changed to silt-mud coast about 100-150 a after the river course was deserted. The erosion depth in the foot of the seawall is calculated based on the formula.

关键词： modern Huanghe River Delta coast evolvement scour depth in the foot of seawall

Sulfate-Methane Transition Depths and Its Implication for Gas Hydrate

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Journal of Ocean University of China 2020年第4期19卷 837-842页

作者： ZHANG Yang LI Guangxue GAO Xinghua Key Laboratory of submarine Sciences and prospecting techniques Ministry of Educationand College of Marine GeosciencesOcean University of ChinaQingdao 266100China

The biological removal of CH4 by methanotrophic(CH4-oxidizing)archaea always occurs at a distinct zone which is known as sulfate-methane transition zone(SMTZ).It is an important indication for high methane flux and gas hydrate *** this study,we collected pore-water data from South China Sea,Carolina Rise and Blake Ridge to analyze the relationship between CH4,SO42−concentration and *** found that below the SMTZ,the methane concentration increases continuously with depth and sulfate concentration decrease linearly to *** addition,the geochemical data taken from all these sites show that SMTZ is relatively shallow(less than 20 m),which may indicate that these areas have high methane flux.

关键词： gas hydrate sulfate-methane transition zone(SMTZ) anaerobic methane oxidation(AMO) South China Sea Carolina Rise and Blake Ridge