Structure and physical properties of the Earth's interior

The studies on the structure and physical properties of the Earths interior done by Chinese geophysicists from 1999 to 2002 were reviewed in this paper. It includes several research areas: the structure of the Earths interiors using seismic tomography, anisotropy of the upper mantle in China and its adjacent areas, quality factor Qb for S waves, subduction zone, mantle discontinuities, physical properties of Earths materials and others. The review concerns mainly the contents, the methods and the results of the studies. It can be seen that new progress in the study on the structure and physical properties of the Earths interior has been made in the last 4 years in China. It is shown on three aspects: advancement made on some preexistent areas; pioneering on some new fields and new methods adopted.

Development of High-Pressure Multigrain X-Ray Diffraction for Exploring the Earth’s Interior

The lower mantle makes up more than a half of our planet’s volume. Mineralogical and petrological experiments on realistic bulk compositions under high pressure–temperature (P–T) conditions are essential for understanding deep mantle processes. Such high P–T experiments are commonly conducted in a laser-heated diamond anvil cell, producing a multiphase assemblage consisting of 100 nm to submicron crystallite grains. The structures of these lower mantle phases often cannot be preserved upon pressure quenching;thus, in situ characterization is needed. The X-ray diffraction (XRD) pattern of such a multiphase assemblage usually displays a mixture of diffraction spots and rings as a result of the coarse grain size relative to the small X-ray beam size (3–5 lm) available at the synchrotron facilities. Severe peak overlapping from multiple phases renders the powder XRD method inadequate for indexing new phases and minor phases. Consequently, structure determination of new phases in a high P–T multiphase assemblage has been extremely difficult using conventional XRD techniques. Our recent development of multigrain XRD in high-pressure research has enabled the indexation of hundreds of individual crystallite grains simultaneously through the determination of crystallographic orientations for these individual grains. Once indexation is achieved, each grain can be treated as a single crystal. The combined crystallographic information from individual grains can be used to determine the crystal structures of new phases and minor phases simultaneously in a multiphase system. With this new development, we have opened up a new area of crystallography under the high P–T conditions of the deep lower mantle. This paper explains key challenges in studying multiphase systems and demonstrates the unique capabilities of high-pressure multigrain XRD through successful examples of its applications.

Passive Seismic Deployments from the Lützow-Holm Bay to Inland Plateau of East Antarctica: The Japanese IPY Contribution to Structure and Seismicity

Deployments of seismic stations in Antarctica are an ambitious project to improve the spatial resolution of the Antarctic Plate and surrounding regions. Several international programs had been conducted in wide area of the Antarctic continent during the International Polar Year (IPY 2007-2008). The “Antarctica’s GAmburtsev Province (AGAP)”, the “GAmburtsev Mountain SEISmic experiment (GAMSEIS)” as a part of AGAP, and the “Polar Earth Observing Network (POLENET)” were major contributions to the IPY. The AGAP/GAMSEIS was an internationally coordinated deployments of more than few tens of broadband seismographs over the wide area of East Antarctica. Detailed information on crustal thickness and mantle structure provides key constraints on an origin of the Gamburtsev Mountains;and more broad structure and evolution of the East Antarctic craton and sub-glacial environment. From POLENET data obtained, local and regional signals associated with ice movements were recorded together with a significant number of teleseismic events. Moreover, seismic deployments have been carried out in the Lützow-Holm Bay (LHB), East Antarctica, by Japanese activities. The recorded teleseismic and local events are of sufficient quality to image the structure and dynamics of the crust and mantle, such as the studies by receiver functions suggesting a heterogeneous upper mantle. In addition to studies on the shallow part of the Earth, we place emphasis on these seismic deployments’ ability to image the Earth’s deep interior, as viewed from Antarctica, as a large aperture array in the southern high latitude.

Anomalous Nuclear Reaction in Earth’s Interior:a New Field in Physics Science?

Tritium （3^H） in excess of the atmospheric values was found at volcanic Lakes Pavin （France）, Laacher （Germany） and Nemrut （Turkey）, as well as Kilauea Volcano at Hawaii （USA） and other volcanoes. Because 3^H has a short half-life of 12.3 years, the tritium and the resulting 3^He must have formed recently in the Earth. The result suggests that nuclear reactions may generate a significant amount of tritium in the interior of the Earth, although we have not yet learned what the reaction mechanism may be responsible. The nuclear reaction that can be responsible for tritium production in the Earth is probably a new research field in physics science. Nuclear reactions that generate tritium might be a source of ＂missing＂ energy （heat） in the interior of the Earth. Finding in-situ 3^H in the mantle may exhibit an alternative explanation of 3^He origin in the deep Earth.

Earth: Review Article

Every year on 22 April, we have celebrated Earth Day and the beautiful planet we call home. Earth Day, established in 1970, has been used to highlight our planet’s environmental challenges and raise awareness of the importance of protecting our world for future generations [1]. To provide the protection of our planet, we should explain Earth’s environmental challenges to the best of our knowledge in frames of contemporary Geophysics. This paper gives a short overview of the developed Hypersphere World-Universe Model (WUM) and pay particular attention to the principal role of Dark Matter (DM) in the Earth’s life. In this manuscript, we discuss different aspects of the Earth: a condition of Young Earth before the Beginning of life on It;Internal Structure;“The 660-km Boundary” that we named Geomagma;Random Variations of Earth’s Rotational Speed on a daily basis;Origin of Moon;Expanding Earth;Internal Heating;Faint Young Sun paradox;Geocorona and Planetary Coronas;High-Energy Atmospheric Physics. WUM proposed principally different ways to solve the problems of Internal Heating, Origin of the Moon, and Faint Young Sun paradox based on DM core of the Earth. The Model revealed the fact that the Sun Activity causes the Geomagma Activity and, as a consequence, Random Variations of Earth’s Rotational Speed by the varying Sun’s magnetic field.

“In Space” or “As Space”?: Spatial Autocorrelation Properties of the Earth’s Interior

In this analysis, natural systems are posed to subsystemize in a manner facilitating both structured information/energy sharing and an entropy maximization process projecting a three-dimensional, spatial outcome. Numerical simulations were first carried out to determine whether n × n input-output matrices could, once entropy-maximized, project a three-dimensional Euclidean metric. Only 4 × 4 matrices could;a small proportion passed the test. Larger proportions passed when grouped random patterns on and within two- and three-dimensional forms were tested. The pattern of structural zonation within the earth was then tested in analogous fashion using spatial autocorrelation measures, and for three time periods: current, 95 million years b.p. and 200 million years b.p. All expected results were obtained;not only do the geometries of zonation project a three-dimensional structure as anticipated, but also do secondary statistical measures reveal levels of equilibrium among the zones in all three cases that are nearly total, distinguishing them from simulations that do not incorporate a varying-surface zone-width element.

中国大陆地壳上地幔S波品质因子三维层析成像

根据欧亚大陆及西太平洋地区 5 8个数字地震台站 2 86 1个长周期波形记录 ,从中挑选出符合条件的 2 2 3对经过中国大陆的双台路径记录 ,采用相匹配滤波和频率域维纳滤波相结合的方法 ,计算出双台之间的混合路径衰减系数 .对中国大陆区域进行网格划分 ,通过网格化反演得到中国大陆区域每个网格单元的纯路径衰减系数 .根据速度和密度模型 ,对每个网格单元进行深度反演 ,得到 10～ 35 0km的S波品质因子Qβ,进而得到整个中国大陆的S波品质因子分布 .结果显示 :研究区域的Qβ 横向和纵向变化非常显著 ,能够明显区分软流圈结构 ,各个大构造单元的Qβ 结构呈现出显著的变化 .这为解释中国大陆区域地球内部介质性质和探讨地球动力学提供了丰富的信息 .

基于岩石样本数据的地球内部物质化学成分统计分析及其对地球构造的影响

地球的内部结构与化学组成对于理解其构造、演化及地质活动非常关键。为深入探讨地球内部物质的化学成分及其与地球构造的关系,从多个地质钻探点收集了大量的岩石样本并进行详细的化学分析,使用统计图表对数据进行可视化。结果显示,地壳主要由硅酸盐矿物组成,富含硅和氧,地幔和核则含有较多的铁、镁及其他重元素,化学成分与地质活动,如地震和火山喷发之间存在密切关系。数据分析显示,地震活动的频率与地区的硅含量之间存在正相关性,这对理解地球内部物质的化学成分及其构造与地质活动至关重要。未来,需要在更深的地方进行钻探研究,结合多学科知识更全面地探索地球内部。

南海北部陆缘反“S”型构造带及其对地震活动的影响

通过地形—地貌、断裂构造、地壳结构、中新生代沉积盆地、第四纪地质特征等分析,认为南海北部陆缘存在滨岸岛链、陆坡北缘和陆坡南缘三条反“S”型构造带,它们形成于晚第三纪,较“新华夏系”和“南海系”晚。上新世末期以来,反“S”型构造带的活动方式,对南海北部陆缘第四纪地质特征影响显著,同时控制了这一区域的地震活动方式和地震带展布,其中,“滨海地震带”和“雷琼地震带”同属于滨岸岛链带,“台西滨外地震带”和“东沙—海南地震带”同属于陆坡北缘带。

对《土坝坝体灌浆技术规范》(SD266-88)修改的建议

《土坝坝体灌浆技术规范》(SD266-88)可分为充填式灌浆和劈裂式灌浆两部分,但重点阐述劈裂式灌浆方面的内容,而这种劈裂式灌浆技术是建立在白氏法基础上的。随着劈裂式灌浆实践的不断深入及应用范围的不断扩大,灌浆理论和施工方面都在不断突破现行规范的限制,出现新的劈裂灌浆施工工艺,如章氏法、循环劈裂式充填灌浆法、新的衍生的劈裂灌浆法等,提出灌浆起始劈裂点、帷幕形态及帷幕耐久性、灌浆压力计算、浆液运动规律的物理模型、复灌次数及复灌间隔时间的确定等问题,都需要充实到新的灌浆规范之中。故提出修改现行规范的具体建议,可扩大劈裂式灌浆至所有土坝(不再限制坝高、坝型),将白氏法劈裂式灌浆中的接触带劈裂灌浆、土坝基础劈裂灌浆、渠道防渗劈裂灌浆、地基无限体劈裂灌浆、基础固结劈裂灌浆,以及章氏法劈裂式灌浆的内容增添到规范中;强调必须进行灌浆试验,确定对堤防工程及土坝岸坡段每孔复灌次数不少于3次,灌浆间隔时间不得少于3 d,计算得到的灌浆压力乘以1.1～1.3的系数等;强调必须以开挖探井检查灌浆效果为主,增加灌浆定额部分,实行监理制度等内容,以便指导灌浆实践活动。

N-二苯基氧化膦亚甲基-(S)-焦谷氨酸及其硝酸铈配合物的合成与表征

新化合物N 二苯基氧化膦亚甲基 (S) 焦谷氨酸(PO PGA)由Ph2PH,HCHO和(S) 谷氨酸在甲醇中通过Mannich反应,然后经H2O2氧化而制得。化合物PO PGA的晶体结构经X射线单晶衍射而确定。晶体为正交晶系,空间群为P212121,晶胞参数a=9.319(2),b=15.512(3),c=2.6456(6)nm,Z=4,Dc=1.273g·cm-3。该标题化合物通过分子间氢键连接形成环二聚体(PO PGA)2(CH3COCH3),空腔大小为0.5656nmⅹ0.3405nm。经元素分析、IR、H1 NMR、P31 NMR和质谱对PO PGA及其和硝酸铈形成的配合物的(PO PGA)2Ce(NO3)3·(H2O)3性质进行了研究。

A Recursive Probabilistic Inversion of Satellite Gradiometry Data for the Upper Mantle Density Variation

We describe a method to perform a constrained lithospheric-scale inversion of satellite gravity gradient data.The a priori constraints include:i)data covariance matrix;ii)prior model covariance matrix including a model for spatial variability of mantle heterogeneity.

Gravitational transformation of gaseous clouds: The formation of spiral galaxies and disk planets

Gravitation is one of the central forces playing an important role in formation of natural systems like galaxies and planets. Gravitational forces between particles of a gaseous cloud transform the cloud into spherical shells and disks of higher density during gravitational contraction. The density can reach that of a solid body. The theoretical model was tested to model the formation of a spiral galaxy and Saturn. The formations of a spiral galaxy and Saturn and its disk are simulated using a novel N-body self-gravitational model. It is demonstrated that the formation of the spirals of the galaxy and disk of the planet is the result of gravitational contraction of a slowly rotated particle cloud that has a shape of slightly deformed sphere for Saturn and ellipsoid for the spiral galaxy. For Saturn, the sphere was flattened by a coefficient of 0.8 along the axis of rotation. During the gravitational contraction, the major part of the cloud transformed into a planet and a minor part transformed into a disk. The thin structured disk is a result of the electromagnetic interaction in which the magnetic forces acting on charged particles of the cloud originate from the core of the planet.

Redox geodynamics in Earth’s interior

Redox state is an important parameter in describing the thermodynamic state of the Earth’s interior.In contrast to the considerable efforts in early studies that have been expended on the redox state of Earth’s different spheres,much attention in the recent about 10 years has been paid to the effects of redox state on the various geodynamical aspects of Earth’s interior,or more commonly the redox geodynamics.Redox geodynamics plays a critical role in driving many processes that are involved in the accretion,differentiation,and re-shaping of the Earth from its early birth to modern periods and from its surface to the deep interior,including the structure,composition,nature,and evolution of the Earth and the significant effects on many important issues such as the climate change and habitability of the planet.This field has blossomed in these years around the chemical and physical properties of the Earth.In this review,a brief summary is provided for the basic concepts,general background and applications relevant to redox geodynamics.The redox state of the crust and mantle and its evolution have received particular attention in the past years,however,there are still fundamental issues remaining ambiguous,poorly quantified and/or even controversial.At the same time,significant progress has been made,mostly through experimental studies,on the redox geodynamics of the Earth’s interior,including(but are not limited to)the early oxidation of the shallow mantle,the rapid growth of the early continental crust,the redox freezing and melting associated with carbon or hydrogen,the transfer of metal elements and formation of ore deposits,the low seismic velocity and high attenuation of the asthenosphere,the aerobic processes around the core-mantle boundary,and the magma degassing and released gases.Redox geodynamics is becoming increasingly important in renewing the understanding of the chemical evolution,physical properties,and dynamical processes of the Earth.

Study of K^+ doping on structure and properties of γ-Ce_2S_3

In this study,K+-doped γ-Ce2 S3 was successfully prepared via a gas-solid reaction method using CeO2,K2 CO3,and CS2 as raw materials.The effects of the suitable sulfide system and different molar ratios of K to Ce(nK/Ce=0-0.30) on the phase composition,crystal structure,chromaticity and thermal stability ofγ-Ce2 S3 were systematically investigated.Pure γ-Ce2 S3 was obtained by calcining the doped samples at840℃ for 150 min.After calcination at the same temperature the undoped K+samples exhibit a pure α-phase.Samples with a K/Ce molar ratio(nK/Ce) of 0.10-0.25 comprise only the γ-phase;and when nK/Ce exceeds 0.25,a new heterogeneous phase,KCeS2,emerges.For values of nK/Ce in the range of0-0.25,the γ-Ce2 S3 lattice parameters gradually increases with increasing K+ content.When nK/Ceexceedes 0.25,the lattice parameters remains unchanged.As nK/Ce increased,the synthesized color gradually changes from red to orange—red and finally,to yellow.The redness value a* reaches the maximum(L*=33.86,a*=36.68,b*=38.15) when nK/Ce=0.10,The nK/Ce=0.10 composition continues to exhibit the y-phase after heat treatment at 420℃ for 10 min in air.The K+doping fills the internal vacancies of γ-Ce2 S3 and formed a solid solution,which is beneficial for the stability of its lattice,thus improving the thermal stability of γ-Ce2 S3(from 350 to 420℃).

On the asymmetric distribution of heat loss from the Earth'sinterior

Mean heat flows and heat losses of the Northern and Southern hemispheres are calculated using degree 12 spherical harmonic representation of the global heat flow field (Pollack et al., 1993). Mean heat flows and heat losses of 0° hemisphere and 180° hemisphere, with median lines being 0° longitude and 180° longitude, are also calculated. The mean heat flow of the Southern Hemisphere is 99.3 mW·m -2, significantly higher than that of the Northern Hemisphere (74.0 mW·m -2). The mean heat flow of 0° hemisphere (94.1 mW·m -2) is also higher than the value of 180° hemisphere (79.3 mW·m -2). The mantle heat loss from the Southern Hemisphere is 22.1×10 12 W, as twice as that from the Northern Hemisphere ( 10.8×10 12 W). The 16.9×10 12 W mantle heat loss from 0° hemisphere is close to 16.0×10 12 W from 180° hemisphere. The hemispherical asymmetry of global heat loss is originated by the asymmetry of geographic distribution of continents and oceans. The asymmetric distribution of heat loss is a long-term phenomenon in the geological history.

Synthesis and crystal structure of complex of Ce(NO_3)_3 with N-(3-methyl-pyridin-2-yl)-formimidoyl-(3-methyl-pyridin-2-yl) hydrazone

The reaction of 3,6-di-(3-methyl-pyridin-2-yl)-s-tetrazine (DMPTZ, II) with CeIII salt [Ce(NO3)3·6H2O] generates a new ligand, N-(3-methyl-pyridin-2-yl)-formimidoyl-(3-methyl- pyridin-2-yl) hydrazone (L), and forms a new complex: a mononuclear complex [Ce(L)(NO3)2 (H2O)3]·NO3 (III). Crystal data for III: space group P-1, with a = 0.7133(4) nm, b = 1.1139(2) nm, c = 1.4572(3) nm, a = 102.13(2)? b = 99.81(3)? g = 91.10(3)? Z = 2, V = 1113.6(7) nm3, m = 2.123 mm-1 and F(000) = 630. L acts as a tri-dentate chelating ligand in III. There are 10 coor-dination sites around Ce3+ of III, which are respectively occupied by seven oxygen atoms (four from two nitrate anions and three from three H2O molecules) and three nitrogen atoms (all from L). The cerium atom and three chelating nitrogen atoms are coplanar. The mechanism of the metal assisted decomposition is discussed briefly.

同步辐射与高压矿物学研究

同步辐射(synchrotron radiation)装置是能产生极高亮度电磁波的一类大科学装置。利用同步辐射和金刚石压腔(DAC)技术,可以研究矿物在高压下的结构和物理性质及其变化。文章简要介绍了同步辐射光源及其特点,对DAC和高压实验技术的相关问题进行了说明,并基于北京同步辐射装置(BSRF)高压站的能量色散X射线衍射(EDXD)实验状况,对获得的部分高压矿物学研究成果,如钙钛矿CaTiO3、硬玉、钛闪石、电气石、绿帘石等矿物的高压结构和状态方程进行了回顾。

地球内部结构和物质性质的研究

对 1999～ 2 0 0 2年中国地球物理学家在地球内部结构和物质性质方面的研究工作进行了总结 .分别对地球内部结构的地震波速度成像研究 ,中国及其周边地区上地幔介质各向异性的研究 ,S波介质品质因子Qβ,俯冲带研究 ,地幔间断面的研究 ,地球物质性质的实验研究以及其它方面的一些研究工作进行了综述 .指出了各方面的主要研究内容、使用的主要方法和得到的结果 .从这 4年的研究中可以发现 ,中国的科学家在地球内部结构和物质性质的研究中又取得了新的进展 ,主要表现在 3个方面 :一些原有领域中的研究更加深入 ;开辟了新的方向 ;

设立“地下明灯研究计划”的建议

20世纪末,空间对地观测技术的发展,获得了地球表面清晰的图像,使人们可以实时地观测地球水圈和大气圈的结构、状态和运动过程,及其与生物圈的相互作用,这是地球系统科学革命性的进展。介绍的“地下明灯研究计划”,其目标是获得地球内部不同深度情况下不同尺度的图像,这些图像是新型的地球内部“三维地图”,它将完善和改变我们对大陆动力学、岩石圈结构和状态的认识。