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Spectral analysis of quasi-stationary sea surface topography from GRACE mission

Science china Earth Sciences 2005年第11期48卷 2040-2048页

作者： zhang {1.2 & lu {3. {3. of Geodesy and geophysics, Chinese Academy of Sciences, wuhan 43.077, china 2. Graduate School of the Chinese Academy of Sciences, Beijing 1.003., china 3. Unite Center for Astro-geodymics Research, Chinese Academy of Sciences, Shanghai 20003., china 1. institute of Geodesy and {1. Chinese Academy of Sciences 430077 Wuhan China 2. Graduate School of the Chinese Academy of Sciences 100039 Beijing China 3. Unite Center for Astro-geodymics Research Chinese Academy of Sciences 200030 Shanghai China

During the last two decades satellite altimetry has offered an abundance of meas-urements of the sea surface resulting in the improvement of global mean sea surface height (MSSH) and marine geoid determination. On the other hand, with the launching of new genera-tion gravity satellites, some high accuracy long-wavelength gravity models are available. These breakthroughs give us a great opportunity for new estimation of quasi-stationary sea surface topography (QSST). In this paper, the new gravity model GGM01. derived from GRACE mission is briefly presented, and a new global high precision and high-resolution QSST is determined based on the GGM01. model and the global MSSH. The spectral features of the QSST esti-mated by GGM01. and EGM96 gravity model to degree/order 200 are discussed by spectral analysis. As a result, the QSST is mainly composed of long waves, medium waves partially and short waves scarcely, its power spectral structures are different between the zonal direction and the meridional direction, there are great differences between the two models, which maybe ex-plain why the ocean currents derived from the two gravity models by Tapley show different pat-terns.

关键词： quasi-stationary sea surface topography, mean sea surface height, GGM01. fast Fourier transform, spectral analysis

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Tectonic setting of the Helong Block:Implications for the northern boundary of the eastern North china Craton

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Science china Earth Sciences 2005年第10期48卷 1599-1612页

作者： zhang Yanbin1. WU Fuyuan1. ZHAI Mingguo{1. lu Xiaoping1.2 1. institute of Geology and geophysics, Chinese Academy of Sciences, P.O. Box 9825, Beijing 1.0029,{3. 2. Regional Geological and Mineral Resources Survey of Jilin Province, Changchun 1.0062,{3. institute of Geology and {1. Chinese Academy of Sciences Beijing china Regional Geological and Mineral Resources Survey of Jilin Province Changchun china

LA-ICP-MS zircon U-Pb dating indicates that the Bailiping granitic pluton was em-placed during Late Paleozoic to Early Cretaceous (285―1.6 Ma) by four distinct magmatic epi-sodes, arguing against the previous thought that the Bailiping granites were emplaced during Archean, Proterozoic or Early Paleozoic. It is suggested that the so-called Archean Jincheng-dong granite-greenstone belt, mainly composed of Bailiping granites, should be broken down. Sr-Nd isotopic compositions of the Bailiping granites are similar to those of the Phanerozoic granites in the Xing’an-Mongolian orogenic belt, suggesting that their parental magmas were mainly derived from a juvenile crust with some contamination of ancient crustal materials during magma rising and/or emplacement. Therefore, the basement of the Helong Block is similar to that in the northern Xing’an-Mongolian Orogenic Belt, but different from that of the North{1. Craton. It is proposed that the Archean Jinchengdong complex in this area is probably an exotic slice from the North{1. Craton, which indicates that the Fu’erhe-Gudonghe Fault, located in northern part of the Helong area, is not the boundary between the North{1. Craton and the Xing’an-Mongolian Orogenic Belt. The possible boundary should be located further southward more than 50 km and near the Baitoushan volcano.

关键词： LA-ICPMS ziron U-Pb dating, Bailiping complex, Helong Block, North china Craton, Sr-Nd isotope.

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Phytolith Analysis for Differentiating between Foxtail Millet(Setaria italica) and Green Foxtail(Setaria viridis)

Phytolith Analysis for Differentiating between Foxtail Mille...

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中国科学院地质与地球物理研究所第1.届（201.年度）学术年会

作者： Jianping zhang~(1.),Houyuan {1.~1.Naiqin Wu~1.Xiaoyan yang~2,Xianmin Diao~3.1.Key Laboratory of Cenozoic Geology and Environment,institute of Geology and {3.,Chinese Academy of Sciences,Beijing,china,2 institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing,china,3.The National Key Facility for Crop Gene Resources and Genetic Improvement, institute of Crop Science,Chinese Academy of Agricultural Sciences,Beijing,china

Foxtail millet {Setaria italica) is one of the oldest domesticated cereal crops in Eurasia,but identifying foxtail millets, especially in charred grains,and differentiating it from its wild ancestor,green foxtail {Setaria viridis),in the archaeobotanical remains,is still *** analysis provides a meaningful method for identifying this important *** this paper,the silicon structure patterns in the glumes,lemmas,and paleas from inflorescence bracts in 1. modern plants of foxtail millet and green foxtail from{1. and Europe are examined using light microscopy with phase-contrast and a microscopic *** research shows that the silicon structure of QUI from upper lemmas and paleas in foxtail millet and green foxtail can be correspondingly divided into two *** size ofΩⅢtype phytolith of foxtail millet is bigger than that from green *** function analysis reveals that 78.4%of data on foxtail millet and 76.9%of data on green foxtail are correctly *** means certain morphotypes of phytoliths are relatively reliable tools for distinguishing foxtail millet from green *** results also revealed that the husk phytolith morphologies of foxtail millets from{1. and Eastern Europe are markedly different from those from Western *** research gives a meaningful method of separating foxtail millet and green *** implications of these findings for understanding the history of foxtail millet domestication and cultivation in ancient civilizations are significant.

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The impacts of '05.6' extreme flood event on riverine carbon fluxes in Xijiang River

The impacts of '05.6' extreme flood event on riverine carbon...

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中国科学院地质与地球物理研究所2007学术年会

作者： SUN HuiGuo~(1.),HAN JingTai~1.zhang ShuRong~2 & {1. XiXi~2 1.institute of Geology and geophysics,Chinese Academy of Sciences,Beijing 1.0029,{3. 2 Department of Geography,National University of Singapore,1.7570,Singapore

An extreme flood event with a frequency of nearly 200 year occurred in June of 2005 in the Xijiang River, the main trunk stream of the Zhujiang *** were systematically collected during the flood event,and water quality parameters,including total suspended sediment(TSS),dissolved inorganic carbon(DIC),dissolved organic carbon(DOC),and particulate organic carbon(POC) were analyzed, and riverine carbon concentrations associated with its changing pattern through the flood process were *** parameters reflect the changes in basin surface flow and subsurface flow during the *** flood event influenced annual flux estimations of POC,DOC,and DIC to great extents. Based on carbon flux estimations for the year 2005 and the flood event(June 21.28) in the Xijiang River,it was found that DIC,DOC,and POC fluxes during‘05.6’ flood event are 1.52×***.a, 0.24×1. ***,and 0.54×1. ***.a,and account for 1..87%,24.75%and 44.89%of the annual fluxes in 2005,*** results suggested that carbon exports during extreme flood events had great contributions to the total carbon fluxes and composition of various carbon components,being important for accurate estimates of annual carbon fluxes in rivers with frequent floods.

关键词： Xijiang River flood riverine carbon flux

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Characterizing three-dimensional features of Antarctic subglacial lakes from the inversion of hydraulic potential——Lake Vostok as a case study

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Advances in Polar Science 2019年第1期30卷 70-75页

作者： LI Yan lu {1. zhang {3. SHI Hongling XI Hui State Key Laboratory of Geodesy and Earth's Dynamics Institute of Geodesy and Geophysics Chinese Academy of Sciences University of Chinese Academy of Sciences

To estimate basal water storage beneath the Antarctic ice sheet, it is essential to have data on the three-dimensional characteristics of subglacial lakes. We present a method to estimate the water depth and surface area of Antarctic subglacial lakes from the inversion of hydraulic potential method. Lake Vostok is chosen as a case study because of the diverse and comprehensive measurements that have been obtained over and around the lake. The average depth of Lake Vostok is around 3.5±4 m. We estimated the surface area of Lake Vostok beneath the ice sheet to be about 1.3.0±594 km^2. The lake consists of two sub-basins separated by a ridge at water depths of about 200–3.0 m. The surface area of the northern sub-basin is estimated to be about half of that of the southern basin. The maximum depths of the northern and southern sub-basins are estimated to be about 450 and 850 m, respectively. Total water volume is estimated to be about 4658±204 km^3. These estimates are compared with previous estimates obtained from seismic data and inversion of aerogravity data. In general, our estimates are closer to those obtained from the inversion of aerogravity data than those from seismic data, indicating the applicability of our method to the estimation of water depths of other subglacial lakes.

关键词： three-dimensional features Lake Vostok hydraulic potential subglacial water storage

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横向同性地层中井间电磁响应的三维频域耦合势正演模拟研究

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地球物理学报 2018年第4期61卷 1639-1650页

作者：张烨林蔺陈桂波李强长春理工大学理学院长春130022 东北电力大学理学院长春132012 中国石油长城钻探工程有限公司测井技术研究院北京100124

本文针对电导率横向同性地层中三轴发射-接收线圈系的井间电磁响应,开展三维正演算法及模拟研究.首先将发射线圈简化为三轴正交磁偶极子源.为克服低频电磁产生的数值迭代收敛缓慢问题,利用低感应数预处理方法将频域Maxwell方程组转化为... 详细信息

本文针对电导率横向同性地层中三轴发射-接收线圈系的井间电磁响应,开展三维正演算法及模拟研究.首先将发射线圈简化为三轴正交磁偶极子源.为克服低频电磁产生的数值迭代收敛缓慢问题,利用低感应数预处理方法将频域Maxwell方程组转化为基于矢势与标势的Helmholtz方程.采用非等间距的Yee氏交错网格、电导率的体积加权平均技术以及积分形式的有限差分格式实现对控制方程的离散化.借助于不完全lu分解预处理的稳定双共轭梯度法计算井间电磁响应的数值解,并通过与有限元软件COMSOL的数值结果对比验证本文模型与算法的有效性.数值计算结果表明:在横向同性地层的垂直井模型中,测井响应横向分量xx和yy能反映出地层电导率各向异性信息,但横向探测能力较差.轴向分量zz虽只反映地层水平电阻率信息,但具有较好的横向探测能力,且对地层中异常体非常敏感,而交叉分量xz、zx则具备较强的层边界识别能力.

关键词：井间电磁测井横向同性地层耦合势有限体积差分三轴线圈系

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40Ar/3.Ar Age Constraints on Two NNE-Trending Ductile Shear Zones,Yanshan Intraplate Orogen,North china Craton

40Ar/39Ar Age Constraints on Two NNE-Trending Ductile Shear ...

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中国科学院地质与地球物理研究所2003.术年会

作者： XIAOHUI zhang,~1.HUI WANG,AND YINGJUN MA Key Laboratory of Mineral Resources,{1. of Geology and {3.,Chinese Academy of Sciences,Beijing 1.0029,{3.

Localized regions of large-magnitude extensional strain typified by metamorphic core complexes are prominent geologic and physiographic features of the Yanshan intraplale *** to typical metamorphic core complexes defined in the Basin and Range Province of the western United States,an exceptional structural feature is the coexistence of seemingly incompatible earlier strike-slip ductile shear zones and later normal faults in metamorphic core complexes within the orogen. Two such important extensional structures are the Louzidian ductile shear zone and the related Louzidian normal fault in the Kalaqin metamorphic core *** Mongolia,and the Waziyu ductile shear zone and the related marginal normal fault of the Fuxin Basin in the Yiwulüshan metamorphic core complex,western Liaoning Province. Field observations and structural analyses reveal that these two NNE-trending ductile shear zones were genetically related to sinistral strike-slip and extensional faulting,and formed under greenschist-facies *** samples from the Louzidian ductile shear zone yield a Ar/Ar biotite plateau age of 1.3.Ma and a Ar/Ar K-feldspar plateau age of 1.6 *** three synkinemalic biotites from the Wazivu ductile shear zone give a Ar/Ar plateau age span of 1.0- 1.6 *** plateau ages record the time of ductile deformation and mylonitization with sinistral strike-slip and extensional movement along the Louzidian and Waziyu ductile shear zones,and thus establish an Early Cretaceous age for such *** similarity of these ages to the lime when regional strike-slip occurred on the Tan-lu fault,large-scale gold metallogenesis took place in Eastern{1.,and the catastrophic mass mortality event resulted in exceptional preservation of the famous Jehol biota imply that these ages not only provide important timing constraints on the first-phase unroofing of the metamorphic core complexes within the Yanshan orogen,but also suggest strong genetic links betwee

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全波形发射电流激发下地面瞬变电磁法磁场特征

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地球物理学报 2024年第6期67卷 2472-2486页

作者：李建慧易淯凯卢绪山王垚章帆中国地质大学(武汉)地球物理与空间信息学院武汉430074 中国地质大学(武汉)地质过程与矿产资源国家重点实验室武汉430074 自然资源部地球物理电磁法探测技术重点实验室河北廊坊065000 加拿大纽芬兰纪念大学地球科学系纽芬兰与拉布拉多省圣约翰斯A1B 3X5

在过去四十年,大部分关于瞬变电磁法的三维建模和反演研究都聚焦于磁场时间导数,而对于磁场数据研究并不多见.如今,随着超导量子干涉仪(SQUID)技术日益成熟,基于磁场数据的瞬变电磁法探测案例逐渐增多.基于矢量有限单元法,采用频谱法和... 详细信息

在过去四十年,大部分关于瞬变电磁法的三维建模和反演研究都聚焦于磁场时间导数,而对于磁场数据研究并不多见.如今,随着超导量子干涉仪(SQUID)技术日益成熟,基于磁场数据的瞬变电磁法探测案例逐渐增多.基于矢量有限单元法,采用频谱法和时步法分别实现了适用于瞬变电磁法磁场数据的三维正演.以低阻覆盖层下的良导体和均匀半空间中板状良导体模型为例,研究了全波形发射电流激发的瞬变电磁法磁场及其时间导数特征,并探讨了二者对深部良导体的探测能力.正演计算结果表明:由于受发射电流全波形效应影响,晚延时磁场随目标体电导率增大而先增强、后减弱,然而即使不考虑全波形效应,磁场时间导数也呈现上述规律;在高阻和低阻围岩情形中,磁场比其时间导数对深部良导体反映更加灵敏,并且晚延时磁场比其时间导数更不易受地磁场背景噪声干扰,说明磁场比其时间导数更适合于深部良导体探测.需要注意的是,发射电流全波形效应降低了瞬变电磁法对深部良导体的识别能力,建议在瞬变电磁法对块状或脉状金属硫化物矿床探测时,尽量采用低基频发射电流波形.

关键词：瞬变电磁法磁场三维正演发射电流全波形

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龙门山断裂带深部结构与2008年汶川地震发震机理

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科学通报 2018年第19期63卷 1906-1916页

作者：雷建设赵大鹏徐锡伟杜沫霏张广伟孙长青米琦鲁明文杨宇何静张冰田凡凡中国地震局地壳应力研究所地壳动力学重点实验室北京100085 Department of geophysics Tohoku University

汶川地震后,为认识发震机理,在龙门山断裂带及周边地区开展了丰富的地震学和地球物理学等方面的野外观测与研究工作,获得了有意义研究成果.近震成像获得的地壳结构显示,以汶川主震震中为界,龙门山断裂带南北两侧波速存在明显差别,以南... 详细信息

汶川地震后,为认识发震机理,在龙门山断裂带及周边地区开展了丰富的地震学和地球物理学等方面的野外观测与研究工作,获得了有意义研究成果.近震成像获得的地壳结构显示,以汶川主震震中为界,龙门山断裂带南北两侧波速存在明显差别,以南地区为明显低波速异常,而以北地区为显著横向不均匀性,这也许可以解释汶川地震的余震为何向东北方向延伸.汶川主震发生在高低波速异常的边界,且其下方存在低波速高泊松比异常.这一结果表明,印度-欧亚板块的碰撞挤压在龙门山断裂带附近形成的高温高压导致了部分熔融或流体作用,降低了断层面处的有效正应力,因而诱发了汶川地震.远震成像获得的上地幔结构显示,龙门山断裂带处于松潘-甘孜地块下方的低波速异常向四川盆地下方的高波速异常的过渡区,且这种结构延伸至200~3.0 km深度,而在地幔转换带中的高波速异常与缅甸弧下方的上地幔高波速异常相连接,说明汶川地震的发生与印度板块深俯冲而形成的"大地幔楔"结构中的低波速异常所代表的热湿物质上涌等动力学过程密切相关.因此,本文认为汶川地震不仅与地壳结构密切相关,而且还受上地幔异常结构的影响.另外,汶川地震还可能与下地壳流、地壳缩短和紫坪铺水库触发等动力学过程有关.

关键词：龙门山断裂带地震层析成像地壳结构地幔结构汶川地震机理

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不同类型地震震级与重力变化异常的统计特征及其机理分析

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地球物理学报 2024年第8期67卷 3032-3059页

作者：李树鹏胡敏章祝意青朱成林崔华伟陆汉鹏张刚王锋吉山东省地震局济南250014 中国地震局地震研究所地震大地测量重点实验室武汉430071 武汉引力与固体潮国家野外科学观测研究站武汉430071 中国地震局第二监测中心西安710054

依据收集到的1.7个4.0级以上地震震例,研究中国陆区中强地震震前重力变化异常统计特征,探讨地震震级与震前重力变化异常各要素及地震性质之间的统计关系,给出了5、6、7、8级地震震级判定的重力变化异常时变距S、量级G和时间T参考指标,... 详细信息

依据收集到的1.7个4.0级以上地震震例,研究中国陆区中强地震震前重力变化异常统计特征,探讨地震震级与震前重力变化异常各要素及地震性质之间的统计关系,给出了5、6、7、8级地震震级判定的重力变化异常时变距S、量级G和时间T参考指标,并对比、分析了逆冲型、走滑型和正断型地震的重力变化特点,进而结合流体物质运移假说及岩石物理实验结果,探讨了震前重力变化异常的物理机制,以及其与亚失稳阶段、地震孕育能量的联系.得到的主要结论有:(1.震前重力变化异常参量与震级之间更符合非线性关系,5、6、7、8级地震的震前重力变化异常时变距参考指标分别为67、1.1.1.5、3.5 km,重力变化异常量级参考指标分别为49、67、92、1.5μGal,重力变化异常时间参考指标分别为1.6、2.5、3.7、5.2 a.(2)地震类型对震前重力变化参量有一定影响,尤其是7级以上强震的差异更加明显,逆冲型地震的重力变化量级及时变距可能更大;重力变化异常时间方面,正断型地震可能对应更长的重力变化时间,逆冲型次之,走滑型最短.(3.震前重力变化异常的物理机制可能是,在孕震晚期、亚失稳阶段,震中周边区域岩石裂隙增多、扩展、贯通,引起流变性的深部幔源物质向地壳运移,同时地壳内先存的流体物质由于应力分布不均而大规模迁移,最终在地表引起重力场变化响应.(4)目前流动重力观测受到时空密度的制约,地震预报主要针对5级以上地震,且震级越大预报效能越好.

关键词：地震预报重力变化异常震级震源机制解

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