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Dynamic mechanisms of the post-seismic deformation following large events:Case study of the 1999 Chi-Chi earthquake in Taiwan of china

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Science china Earth Sciences 2009年第11期52卷 1813-1824页

作者： zhu ShouBiao1,2 & CAI YongEn2 1 Institute of Crustal Dynamics, china Earthquake Administration, beijing 100085, china 2 department of geophysics, peking university, beijing 100871, china Institute of Crustal Dynamics China Earthquake Administration Beijing China department of geophysics Peking University Beijing China

The mechanism of postseismic deformation related to strong earthquakes is important in geodynamics, and presumably afterslip or viscoelastic relaxation is responsible for the postsesimic deformation. The 1999 Chi-Chi, Taiwan of china, earthquake occurred in the region where GPS observation station is most densely deployed in the world. The unprecedented GPS data provides a unique opportunity to study the physical processes of postseismic deformation. Here we assume that the interactions of viscoelastic relaxation, afterslip, fault zone collapse, poroelastic rebound, flow of underground fluids, and all these combined contribute to the surface displacements following the main shock. In order to know the essence of the postseismic deformation after the strong event, fault zone collapse, poroelastic rebound, flow of underground fluids, and so on, are represented equivalently by the variations of the focal medium properties. Therefore, the viscoelastic relaxation, afterslip, and the variations of the equivalent focal medium properties are inverted by applying the GPS temporal series measurement data with viscoelastic finite element method. Both the afterslip rate distribution along the fault and the afterslip evolution with time are obtained by means of inversion. Also, the preliminary result suggests that viscosities of the lower crust and the upper mantle in Taiwan region is 2.7×1018 and 4.2×1020 Pa·s, respectively. Moreover, the inversion results indicate that the afterslip contributing to postseismic deformation of 44.6% in 450 days after the Chi-Chi earthquake, with 34.7% caused by the viscous relaxation and 20.7% by other factors such as fault zone collapse, poroelastic rebound, and the flow of liquids.

关键词： mechanism of postseismic deformation viscoelastic finite element method GPS temporal series data Chi-Chi earthquake

A holistic perspective on Earth system science

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Science china Earth Sciences 2024年第10期67卷 3013-3040页

作者： Yongfei ZHENG Zhengtang GUO Nianzhi JIAO Mu MU Shilong PIAO Suiyan FU Dinghui yang Maoyan zhu State Key Laboratory of Lithospheric and Environmental Coevolution School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China State Key Laboratory of Lithospheric and Environmental Coevolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China School of Ocean and Earth Sciences Xiamen UniversityXiamen 361102China department of Atmospheric and Oceanic Sciences Fudan UniversityShanghai 200438China School of Environment Peking UniversityBeijing 100871China School of Earth and Space Sciences Peking UniversityBeijing 100871China department of Mathematical Sciences Tsinghua UniversityBeijing 100084China Nanjing Institute of Geology and Palaeontology Chinese Academy of SciencesNanjing 210008China

Earth system can be categorized into three parts, solid Earth system, surface Earth system, and Sun-Earth space system. These three subsystems not only have mutual transmission and coupling relationships in both energy and matter but also involve multiple scales from microscopic to macroscopic. Earth system science is characterized by its globality and unity with a holistic view and a systematic view at multiple scales in both space and time. It focuses not only on the physical, chemical and biological interactions between various geospheres but also on the properties, behaviors, processes, and mechanisms of the entire Earth and its spheres. Although significant progress has been made in the study of internal disciplines of these three subsystems,there is still insufficient understanding of their overall behavior and interactions between individuals, thus facing challenges of different types and levels. The solid Earth system is composed of the crust, mantle, and core. Existing observational techniques struggle to penetrate deep into the mantle, making direct observation and data acquisition difficult;the extreme environments within Earth, such as high temperature, high pressure, and strong magnetic fields, also pose great challenges to observational equipment and scientific experiments. The surface Earth system is an open complex mega-system, in which there are complex interactions and feedback mechanisms among its geospheres(such as atmosphere, hydrosphere, biosphere, pedosphere and lithosphere), leading to difficulties in understanding of its overall behavior and long-term evolution. Biological activities have become increasingly significant in affecting the surface Earth system. The coupling between the internal and external Earth systems becomes more complex. Distinguishing and quantifying the impacts of Earth spherical interactions and biological activities on the surface Earth system is a major challenge. The Sun-Earth space system involves multiple physical

关键词： Earth's interior Earth's exterior Geospheres Energy exchange Material transfer

Analysis of the observation of particle detector inside ‘CBERS-1’ satellite under solar quiet conditions

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Science china(Technological Sciences) 2006年第3期49卷 342-357页

作者： ZOU Hong1, XIAO Zuo1, HAO Yongqiang1, ZOU Jiqing1, zhu Wenming2, WU Zhongxiang2 & XIANG Hongwen2 1. department of geophysics, peking university, beijing 100871, china 2. Chinese Academy of Space Technology, beijing 100086, china department of geophysics Peking University Beijing China Chinese Academy of Space Technology Beijing China

Based on the knowledge and related theory of earth’s radiation belt, the data of energetic particles observed by detectors onboard ‘CBERS-1’ satellite at a solar syn- chronous orbit were analyzed. It is proved that the observational results are in agreement with the theoretical description of the radiation belt structures. Analysis of more than 3 years’ data showed clearly that under quiet solar conditions, at a height of about 800 km the energetic particles were mainly located in three regions: northern auroral belt (40°― 80°), southern auroral belt (?40°― ?80°) and South Atlantic Geomagnetic Anomaly Re- gion (SAA). Actually, this is for the global distribution, at each longitude the latitudinal coverage is much narrower and particles are along the geomagnetic latitude of about ±60°. The species of particles in different regions and their counting rates are different. In SAA, usually both electrons and protons are observed, which should come from inner radiation belt; in polar regions only energetic electrons are observed under the quiet condition, which belongs to the outer radiation belt. The distribution of outer radiation electrons is asymmetrical for longitudes as well as northern and southern polar regions. These asymmetries can be explained with the reflecting altitudes of the mirror points of charged particles at the same L shell.

关键词： radiation-belts, energetic-particle, drift-shell, mirror-point.

Flooding 1990s along the yangtze River, has it concern of global warming?

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Journal of Geographical Sciences 2001年第1期11卷 43-52页

作者： GONG Dao-yi1, zhu Jin-hong2, WANG Shao-wu2 (1. Key Laboratory of Environmental Change and Natural Disaster, Institute of Resources Science, beijing Normal university, beijing 100875, china 2. department of geophysics, peking university, beijing 100871, Key Laboratory of Environmental Change and Natural Disaster Institute of Resources Science Beijing Normal University Beijing China department of geophysics Peking University Beijing China

There were a series of severe floods along the middle to lower reaches of the yangtze River (Changjiang River) in china during the 1990s. The extensive summer (June, July and August) precipitation is mostly responsible for the flooding. The summer rainfall in the 1980s and the 1990s is much higher than that in the previous 3 decades. The means for 1990–1999 is +87.62 mm above normal, marked the 1990s the wettest decade since the 1950s. Six stations with a time span of 1880–1999 are selected to establish century-long rainfall series. This series also shows that the 1990s is the wettest decade during the last 120 years. In the wettest 12 years, four occurred in the 1990s (1991, 1996, 1998 and 1999). Both global and china’s temperature show there is a relative lower air temperature during the 1960–1970s, and a rapid warming in the 1980–1990s. Comparisons of rainfall between 1960–1979 and 1980–1999 show there are dramatic changes. In the cold period 1960–1979, the summer rainfall along the yangtze River is 3.8 % to 4.7 % below the normal, during the warm period 1980–1999, over 8.4 % to 18.2 % of summer rainfall occurs. Over the whole eastern china, the summer rainfall shows opposite spatial patterns from the 1960–1970s to 1980–1990s. The consistent trend toward more rainfall with global warming is also presented by the greenhouse scenario modeling. A millennial Drought/flood Index for the middle to lower reaches of the yangtze River showed that although the surplus summer rainfall in the 1990s is the severest during the past 150 years, it is not outstanding in the context of past millennium. Power spectra of the Drought/flood Index show significant interdecadal periods at 33.3 and 11.8 years. Thus, both the natural interdecadal variations and the global warming may play important roles in the frequent floods witnessed during the last two decades.

关键词： summer rainfall yangtze River global warming interdecadal variation

Origin of tectonic stresses in the Chinese continent and adjacent areas

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Science china Earth Sciences 2007年第1期50卷 67-74页

作者： zhu ShouBiao1,2& SHI YaoLin3 1 Institute of Crustal Dynamics, china Earthquake Administration, beijing 100085, china 2 department of geophysics, peking university, beijing 100871, china 3 Laboratory of Computational Geodynamics, Graduate university of Chinese Academy of Sciences, beijing 100049, china Institute of Crustal Dynamics China Earthquake Administration Beijing 100085 China department of geophysics Peking University Beijing 100871 China Laboratory of Computational Geodynamics Graduate University of Chinese Academy of Sciences Beijing 100049 China

Based on data of principal stress orientation from focal mechanism and of geological features in china, we made pseudo-3D genetic algorithm finite element (GA-FEM) inversion to investigate the main forces acting on the Chinese continent and adjacent areas which form the Chinese tectonic stress field. The results confirm that plate boundary forces play the dominant role in forming the stress field in china, as noticed by many previous researchers. However, we also find that topographic spreading forces, as well as basal drag forces of the lower crust to the upper crust, make significant contribution to stresses in regional scale. Forces acting on the Chinese continent can be outlined as follows: the collision of the India plate to the NNE is the most important action, whereby forces oriented to the NW by the Philippine plate and forces oriented to the SWW by the Pacific plate are also important. Topographic spreading forces are not negligible at high topographic gradient zones, these forces are perpendicular to edges of the Tibetan Plateau and a topographic gradient belt running in the NNE direction across Eastern china. Basal drag forces applied by the ductile flow of the lower crust to the base of upper crust affect the regional stress field in the Tibetan Plateau remarkably, producing the clockwise rotation around the eastern Himalaya syntax.

关键词： genetic algorithm finite element method topographic spreading forces ductile lower crust Chinese continent.

Global and china temperature changes associated with the inter-decadal variations of East Asian summer monsoon advances

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Chinese Science Bulletin 2012年第30期57卷 3923-3930页

作者： QIAN WelHong LIN Xiang zhu yafen department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China Institute of Climate System Chinese Academy of Meteorological SciencesBeijing 100081China

The modern atmospheric observation and literatural historical drought-flood records were used to extract the inter-decadal signals of dry-wet modes in eastern china and reveal the possible relationship of global and china temperature changes associated with the East Asian summer monsoon advances.A climate pattern of "wet-north and dry-south" in eastern china and cool period in china and globe are associated with the strong summer monsoon that can advance further to the northernmost part in the East Asian monsoon *** the contrary,a climate pattern of "dry-north and wet-south" in eastern china and a warm period in china and globe are associated with the weaker summer monsoon that only reaches the southern part in the *** interdecadal oscillation with the timescale about 60 years was found dominating in both the dry-wet mode index series of the East Asian summer monsoon and the global temperature series after the secular climate states and long-term trend over inter-centennial timescales have been removed.

关键词：东亚夏季风中国东部年代际变化温度变化夏季季风气候模式时间尺度东亚季风区

THE ADVANCES IN OPERATIONAL NUMERICAL WEATHER PREDICTION AT NATIONAL METEOROLOGICAL CENTER IN china

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Acta Meteorologica Sinica 1988年第1期 116-126页

作者：章基嘉廖洞贤葛蔼芬刘还珠朱抱真陈受钧 State Meteorological Administration beijing Institute of Atmospheric Physics Academia Sinica department of geophysics peking university

Since 1982, several modifications in the operational model in National Meteorological Center(NMC) of china have been made, such as the adoption of the lateral boundary condition formulated byHovermal, Shuman’s economic time difference scheme in the 5-layer Northern Hemispheric Model,and the replacement of the convective adjustment scheme by Kuo’s cumulus parameterization scheme1974) in the 5-layer FLM. Owing to these modifications, both the objective and subjective verificationsof the prediction show that the accuracy of operational NWP has been significantly ***, applications of NWP Products are briefly summarized and future prospects are given.

关键词： NWP THE ADVANCES IN OPERATIONAL NUMERICAL WEATHER PREDICTION AT NATIONAL METEOROLOGICAL CENTER IN china than over AT

1977年1月500mb的大气环流及动能转换关系

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气象学报 1983年第1期 14-23页

作者：仇永炎朱亚芬北京大学地球物理系

1977年1月是北半球中纬大陆地区近年来最严寒的一个月。利用500 mb逐日资料,进行了天气学和能量学的研究,所得结果如下: (1)这个月极区经常出现高压,而且阿拉斯加高压脊特别强而稳定。由于极区高压,高纬西风动量大量地往中纬输送,造成... 详细信息

1977年1月是北半球中纬大陆地区近年来最严寒的一个月。利用500 mb逐日资料,进行了天气学和能量学的研究,所得结果如下: (1)这个月极区经常出现高压,而且阿拉斯加高压脊特别强而稳定。由于极区高压,高纬西风动量大量地往中纬输送,造成高纬强东风。 (2)对于这个月月平均基本气流,进行正压不稳定度判据的检定,发现存在接近正压不稳定的条件。同时,有供给涡动发展的能量。 (3)这个月涡动中,最活跃的是n=3波,寒潮爆发主要是同3波盛行期相联系。3波之所以异常活跃,是由于从2波接受异常多的能量。 (4)2波输出能量较往年多一倍以上,主要输送给3波,对3波发展起着重要作用。对这些结果进行了物理上的联系和讨论。

关键词：大气环流中纬西风行星环流大气现象正压不稳定极地高压极地反气旋基本气流涡动高纬动能收支北半球动能转换率

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磁尾的平衡结构

空间科学学报 1982年第3期 215-223页

作者：丁大庆傅竹风北京大学地球物理系中国科学院空间物理研究所

考虑到等离子体片和等离子体幔的存在,我们从Vlasov方程出发得出一个自洽的二维磁尾平衡模式。在这个模式中,假设等离子体处于平衡状态,压强是各向同性的,还假设沿磁尾方向各种参数的变化率较垂直于等离子体片方向的变化率要小得多。晨... 详细信息

考虑到等离子体片和等离子体幔的存在,我们从Vlasov方程出发得出一个自洽的二维磁尾平衡模式。在这个模式中,假设等离子体处于平衡状态,压强是各向同性的,还假设沿磁尾方向各种参数的变化率较垂直于等离子体片方向的变化率要小得多。晨昏方向的变化则完全忽略不计。这个模式体现出磁尾的一些主要结构要素:(ⅰ)高温等离子体组成的等离子片;(ⅱ)等离子体片中的闭合磁力线;(ⅲ)等离子体极其稀薄的磁尾瓣;(ⅳ)等离子体幔;(ⅴ)磁层顶;(ⅵ)张开的磁尾。讨论了等离子体幔的存在对磁尾平衡结构的影响,结论是等离子体幔的存在使磁尾的形状更趋于尾形,于是,至少部分克服了Birn模式的困难。

关键词：磁尾平衡结构等离子体磁层磁力线