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Layer-Stripping Full Waveform Inversion with Damped Seismic Reflection Data

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Journal of Earth Science 2011年第2期22卷 241-249页

作者：卞爱飞於文辉 institute of Geophysics & geomatics China University of Geosciences

Full waveform inversion（FWI） directly minimizes errors between synthetic and observed *** the surface acquisition geometry,reflections generated from deep reflectors are sensitive to overburden structure,so it is reasonable to update the macro velocity model in a top-to-bottom *** models dominated by horizontally layered structures,combination of offset/time weighting and constant update depth control（CUDC） is sufficient for layer-stripping *** requires ray tracing to determine reflection traveltimes at a constant *** model complexity increases,the multi-path effects will have to be *** developed a new layer-stripping FWI method utilizing damped seismic reflection data,which does not need CUDC and ray *** examples show that effective update depth（EUD） can be controlled by damping constants even in complex regions and the inversion result is more accurate than conventional methods.

关键词： full waveform inversion velocity model building layer-stripping strategy dampedwave equation sensitivity analysis.

Identification of the Caroline Plate boundary:constraints from magnetic anomaly

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Acta Oceanologica Sinica 2024年第8期43卷 1-12页

作者： Yongtao Fu Guoliang Zhang Wanyin Wang An Yang Tao He Zhangguo Zhou Xiao Han Key Laboratory of Ocean Observation and Forecasting/Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China National Engineering Research Center for Offshore Oil and Gas Exploration Beijing 100028China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China Center of Deep Sea Research Institute of OceanologyChinese Academy of SciencesQingdao 266071China institute of Gravity and Magnetic Technology Key Laboratory of Western China’s Mineral Resources and Geological Engineering of Ministry of EducationSchool of Geology Engineering and GeomaticsChang’an UniversityXi’an 710054China University of Chinese Academy of Sciences Beijing 100049China

The Caroline Plate is located among the Pacific Plate,the Philippine Sea Plate,and the India Australia Plate,and plays a key role in controlling the spreading direction of the Philippine Sea *** Caroline Submarine Plateau(or Caroline Ridge)and the Eauripik Rise on the south formed a remarkable T-shaped large igneous rock province,which covered the northern boundary between the Caroline Plate and the Pacific ***,relationship between these tectonic units and magma evolution remains *** on magnetic data from the Earth Magnetic Anomaly Grid(2-arc-minute resolution)(V2),the normalized vertical derivative of the total horizontal derivative(NVDR-THDR)technique was used to study the boundary of the Caroline *** show that the northern boundary is a transform fault that runs 1400 km long in approximately 28 km wide along the N8°in E-W *** eastern boundary is an NNW-SSE trending fault zone and subduction zone with a width of tens to hundreds of kilometers;and the north of N4°is a fracture zone of dense *** southeastern boundary may be the Lyra *** area between the southwestern part of the Caroline Plate and the Ayu Trough is occupied by a wide shear zone up to 100 km wide in nearly S-N trending in *** Eauripik transform fault(ETF)in the center of the Caroline Plate and the fault zones in the east and west basins are mostly semi-parallel sinistral NNW-SSE–trending faults,which together with the eastern boundary Mussau Trench(MT)sinistral fault,the northern Caroline transform fault(CTF),and the southern shear zone of the western boundary,indicates the sinistral characteristics of the Caroline *** Caroline hotspot erupted in the Pacific Plate near the CTF and formed the west Caroline Ridge,and then joined with the Caroline transform fault at the N8°.A large amount of magma erupted along the CTF,by which the east Caroline Ridge was *** the same time,a large amount of magma developed southward via the e

关键词： Caroline Plate magnetic anomaly normalized vertical derivative of the total horizontal derivative plate boundary Caroline Ridge Eauripik Rise

Well Logging Responses of UHP Metamorphic Rocks from CCSD Main Hole in Sulu Terrane,Eastern Central China

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Journal of Earth Science 2010年第3期21卷 347-357页

作者：骆淼潘和平 institute of Geophysics & geomatics China University of Geosciences Wuhan

The lithologies of the Chinese Continental Scientific Drilling main hole （CCSD-MH） are mainly comprised of orthogneiss,paragneiss,eclogite,amphibolite,and ultramafic *** statistical results of logs of CCSD-MH indicate that ultramafic rocks are characterized by very high CNL （neutron log） and very low GR （gamma ray log） and RD （resistivity log）;eclogites are characterized by high DEN （density）,VP （P-wave velocity） and PE （photoelectric absorption capture cross section）;orthogneiss and paragneiss are characterized by high GR,U （uranium content）,Th （thorium content）,K （potassium content） and RD,and low DEN,PE,and CNL;logging values of amphibolite are between the logging values of eclogites and *** addition,the logs could reflect the degree of retrograde metamorphism of *** upper section （100-2 000 m） shows higher DEN,PE,VP,and lower GR,U,Th,K,RD than the lower section （2 000-5 000 m）.Most logs of the upper section are more fluctuant than those of the lower *** indicates that the upper section has more heterogeneities than the lower *** cross plots of logs indicate that DEN,GR,K,and CNL are more powerful in identifying ultrahigh pressure metamorphic （UHPM） rocks at the *** value of the rocks from CCSD-MH shows obviously an increasing trend from ultramafic rock （the most mafic rocks at CCSD-MH） to orthogneiss （the most acid rocks at CCSD-MH）.On the contrary,DEN value decreases from the ultramafic rock to the *** log is a good indicator of the content of structure water in crystalline rocks.

关键词： ultrahigh pressure metamorphic rock CCSD main hole well logging response

Why are Q-Ratios High in the Sulu UHP Metamorphic Rocks?

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Journal of Earth Science 2011年第1期22卷 115-116页

作者：刘庆生 institute of Geophysics & geomatics China University of Geosciences

I found high Q values （Q-ratio=Jn/Ji, .In, Ji are remanent magnetization and induced magnetization） in the Sulu ultrahigh pressure （UHP） metamorphic rocks, eastern China which is the world＇s largest UHP metamorphic belt （Fig. 1 in Liu et al., 2009）. Q values of 320 core samples with variable lithologies in the 100--2 000 m interval from the Chinese Continental Scientific Drilling （CCSD） main hole are as follows： values between 0.06 and 608.24, with an average of 15.56 for 171 eclogite samples;

关键词： UHP high Why are Q-Ratios High in the Sulu UHP Metamorphic Rocks

Geophysical Exploration for Geothermal Resources:An Application of MT and CSAMT in Jiangxia,Wuhan,China

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Journal of Earth Science 2012年第5期23卷 757-767页

作者：吴桂桔胡祥云霍光谱周晓晨 institute of Geophysics&geomatics China University of Geosciences

We present a case study of applying MT （magnetotellurics） and CSAMT （controlled source audio-frequency magnetotelluries） for geophysical exploration in Jiangxia （江夏）, which is located in new industrial developing suburb, where artificial noises are severe. In order to know deep buried structure, fracture status, and characteristics of underground geothermal development about 2 km, we acquired MT and CSAMT data to image subsurface structure through inversion and joint interpretation. The electrical terms of the 2D MT inversion can be divided into three ranges of resistivity values：（1） a highly resistive （〉350 ~.m） layer mainly characteristic of limestone, dolomitic limestone, leuttrite, silicarenite, and packsand; （2） an intermediate resistivity （250-350 Ω·m） layer mainly constituted by siliceous shale, siltstone, battie, and ampelitic limestone; and （3） a low resistivity （20-250 Ω·m） layer, from surface to-100 m, which is related to lacustrine alluvium of Quaternary period; the deep low resistivity layer is interpreted to be representative of the geothermal field. The result of the 2D CSAMT inversion reveals two layers of different electrical resistivities：（1） the first resistive layer （20-250 Ω·m）, which is related to lacustrine alluvium of Quaternary period and the heat source, and （2） the second resistive layer （250-3 000Ω·m）. The heat source appears to be bounded within the middle of exploration area and shows the N-S trend. Its depth ranges from more than 1.2 to less than 0.7 km, and its resistivity values range from 20 to 250 Ω·m in the northeast part of Jiangxia. Comparing the results of MT and CSAMT method, the positive anomalies are similar and can be assumed to be generated by the same source.

关键词： MT method CSAMT method resistivity structure geothermal field.

Derivative-Based Techniques for Geological Contact Mapping from Gravity Data

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Journal of Earth Science 2010年第3期21卷 358-364页

作者：李媛媛杨宇山刘天佑 institute of Geophysics & geomatics China University of Geosciences Wuhan

Gravity anomalies illuminate subsurface lithology and geological structure in three dimensions,which is vital for studies of concealed faults,sedimentary basins,basement lithology,and other geological *** not all geological contacts correspond to lithological contacts,the contact mapping provides key information on structural regimes,deformation styles and *** techniques for contact mapping have been ***,we evaluate five methods applied to gridded *** first two are the horizontal gradient magnitude of the gravity field （GFhgm）,and tilt （TIhgm）.The third and fourth rely on locating maxima of the analytic signal （AS） and the 3D local wavenumber （LW）.The fifth is normalized standard deviation （NSTD） *** this article,we evaluate the use of these five methods for mapping contacts and compare the ***,synthetic vertically-sided models are used to quantify the offsets of maxima from the true contact location due to the source effects of finite source thickness,central depth,and ***,the effects of contact dip are ***,a real data set is used to evaluate the ability of each method to produce maps of coherent contact trends in the presence of noise and gridding artifacts.

关键词： gravity contact mapping tilt local wavenumber analytical signal normalized standard deviation

Change monitoring of earth rotation parameter with Maglev gyroscope precessional torque

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中国有色金属学会会刊：英文版 2011年第S3期21卷 589-593页

作者： YANG Zhi-qiang, GONG Yun, SHI Zhen, LI Yun Geological Engineering and geomatics institute, Chang’an University, Xi’an 710054, China Geological Engineering and geomatics institute Chang'an University Xi'an 710054 China

Through analyzing the relationship between gyro dynamic torques produced by the changes of earth rotation parameters (ERP), a method of measuring the earth rotation parameters was proposed and explored by using gyroscope. The preliminary experiments were carried out using GAT Maglev Gyro Station (which is self-developed by China). Considering the measurement and expanding-application of the earth rotation parameters, some ideas and opinions about the structure design, measurement methods and data processing of gyro were proposed, and some outlook of the expanding-application of the gyroscope in geodetic and geophysical fields were done. The experimental results show that using the high-precision gyroscope to determine the changes of ERP is feasible, with the emergence of ultra-high precision gyro; it is possible for determining the earth rotation parameters by gyro in stead of by current complex space surveying technology.

关键词： Maglev gyroscope earth rotation parameters (ERP) precessional torque pole motion length of day

Reconciled estimation of Antarctic ice sheet mass balance and contribution to global sea level change from 1996 to 2021

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Science China Earth Sciences 2024年第11期67卷 3562-3578页

作者： Rongxing LI Guojun LI Gang HAI Huan XIE Yuan CHENG Wei CHEN Xiangbin CUI Minghu DING Chunchun GAO Tong HAO Changqing KE Chuanjin LI Jin LI Yan LIU Jiangjun RAN Jiawen REN Qiang SHEN Yunzhong SHEN Hongling SHI Songyun WANG Zemin WANG Jingang ZHAN Baojun ZHANG Min ZHONG Chunxia ZHOU Center for Spatial Information Science and Sustainable Development Applications Tongji University College of Surveying and Geo-informatics Tongji University institute for the Conservation of Cultural Heritage School of Cultural Heritage and Information Management Shanghai University College of Resource Environment and Tourism Hubei University of Arts and Science Polar Research institute of China State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences College of Geodesy and geomatics Shandong University of Science and Technology School of Geography and Ocean Science Nanjing University Shanghai Astronomical Observatory Chinese Academy of Sciences State Key Laboratory of Remote Sensing Science Faculty of Geographical Science Beijing Normal University Department of Earth and Space Sciences Southern University of Science and Technology State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences State Key Laboratory of Geodesy and Earth's Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of Sciences Center for Space Research University of Texas at Austin Chinese Antarctic Center of Surveying and Mapping Wuhan University School of Geospatial Engineering and Science Sun Yat-sen University

The Antarctic Ice Sheet（AIS） has been losing ice mass and contributing to global sea level rise（GSLR）. Given its mass that is enough to cause ～58 m of GSLR, accurate estimation of mass balance trend is critical for AIS mass loss monitoring and sea level rise forecasting. Here, we present an improved approach to reconciled solutions of mass balance in AIS and its regions from multiple contributing solutions using the input-out, altimetric, and gravimetric methods. In comparison to previous methods, such as IMBIE 2018, this approach utilizes an adaptive data aggregation window to handle the heterogeneity of the contributing solutions, including the number of solutions, temporal distributions, uncertainties, and estimation techniques. We improved the regression-based method by using a two-step procedure that establishes ensembled solutions within each method（input-output, altimetry, or gravimetry） and then estimates the method-independent reconciled solutions. For the first time, 16contributing solutions from 8 Chinese institutions are used to estimate the reconciled mass balance of AIS and its regions from1996 to 2021. Our results show that AIS has lost a total ice mass of ～3213±253 Gt during the period, an equivalent of～8.9±0.7 mm of GSLR. There is a sustained mass loss acceleration since 2006, from 88.1±3.6 Gt yr-1during 1996–2005 to 130.7 ±8.4 Gt yr-1during 2006–2013 and further to 157.0±9.0 Gt yr-1during 2014–2021. The mass loss signal in the West Antarctica and Antarctic Peninsula is dominant and clearly presented in the reconciled estimation and contributing solutions, regardless of estimation methods used and fluctuation of surface mass balance. Uncertainty and challenges remain in mass balance estimation in East Antarctica. This reconciled estimation approach can be extended and applied for improved mass balance estimation in the Greenland Ice Sheet and mountain glacier regions.

关键词： Antarctic Ice Sheet Ice mass loss acceleration Sea level rise Reconciled estimation

Body Waves Revealed by Spatial Stacking on Long-Term Cross-Correlation of Ambient Noise

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Journal of Earth Science 2014年第6期25卷 977-984页

作者： Kai Wang Yinhe Luo Kaifeng Zhao Limeng Zhang institute of Geophysics and geomatics China University of Geosciences State Key Laboratory of Geological Processes and Mineral Resources Institute of Geophysics and GeomaticsChina University of Geosciences Subsurface Multi-Scale Imaging Key Laboratory (SMIL) of Hubei Province Institute of Geophysics and GeomaticsChina University of Geosciences

Theoretical and experimental studies indicate that complete Green＇s Function can be retrieved from cross-correlation in a diffuse field. High SNR（signal-to-noise ratio） surface waves have been extracted from cross-correlations of long-duration ambient noise across the globe. Body waves, not extracted in most of ambient noise studies, are thought to be more difficult to retrieve from regular ambient noise data processing. By stacking cross-correlations of ambient noise in 50 km inter-station distance bins in China, western United States and Europe, we observed coherent 20–100 s core phases（Sc S, PKIKPPKIKP, PcP PKPPKP） and crustal-mantle phases（Pn, P, PL, Sn, S, SPL, SnS n, SS, SSPL） at distances ranging from 0 to 4000 km. Our results show that these crustal-mantle phases show diverse characteristics due to different substructure and sources of body waves beneath different regions while the core phases are relatively robust and can be retrieved as long as stations are available. Further analysis indicates that the SNR of these body-wave phases depends on a compromise between stacking fold in spatial domain and the coherence of pre-stacked cross-correlations. Spatially stacked cross-correlations of seismic noise can provide new virtual seismograms for paths that complement earthquake data and that contain valuable information on the structure of the Earth. The extracted crustal-mantle phases can be used to study lithospheric heterogeneities and the robust core phases are significantly useful to study the deep structure of the Earth, such as detecting fine heterogeneities of the core-mantle boundary and constraining differential rotation of the inner core.

关键词： ambient noise cross-correlation body wave