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THINNING OF THE THICKENED LITHOSPHERE AND ITS GEODYNAMIC CONSEQUENCE: APPLICATION FOR TIBETAN PLATEAU

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地学前缘 2000年第S1期7卷 368-369页

作者： Xiong Xiong,Houtse Hsu (institute of geodesy and {2., chinese academy of Sciences, Wuhan 430077, china)

As one of the most distinct tectonic blocks on the Earth’s surface, Tibetan Plateau draw great attention of the geoscientists from the world. Many authors have proposed various kinds of the mechanism to try to clarify the evolution of the plateau. While many studies are often restricted to crustal units, the important role of the mantle part of the lithosphere (mantle lithosphere) during and after the collision process has not been appreciated widely. The purpose of the paper is to investigate the dynamic process of the thinning (delamination and convective removal) of the thickened lithosphere and its influence upon the uplift of the plateau.1\ Thickened lithosphere root\;Parsons and McKenzie (1978) proposed that the continental lithosphere could be thought of as consisting of two distinct parts: the mechanical and thermal boundary layers. The lower, and hotter, part is the thermal boundary layer. Its viscosity is sufficiently low that the force of gravity acting on density contrasts between the thermal boundary layer and the underlying mantle lead to the episodic sinking of the thermal boundary layer and its replacement by hot asthenosphere. When continental crust shortens and thickens, the mantle directly beneath it must also be displaced downward. In other words, mountain building process shortens horizontally and thickens vertically the mechanical boundary layer, and presumably the thermal boundary layer. And the process stretches the isotherms vertically, thus reducing the geothermal gradient. Houseman’s numerical experiments (1981) show that thickening of the thermal boundary layer enhances the density contrasts between it and the underlying asthenosphere, and so leads to its removal and replacement with hot asthenosphere. This phenomenon is called the instability of the thickened lithosphere.

关键词： thinning thickened lithosphere Tibetan Plateau uplift

Method of multi-level recursive and application to nonlinear dynamic deformation forecasting

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中国有色金属学会会刊：英文版 2005年第S1期15卷 172-175页

作者： LIU Guo-lin~(1, 2., ZHANG Lian-peng~2. OU Ji-kun~1 (1. institute of geodesy and {2., chinese academy of Science, Wuhan, 430077,china 2. Shandong University of Science and Technology, Tai’an 2.1019, china) chinese Acad Sci Inst Geodesy & Geophys Wuhan 430077 Peoples R China Shandong Univ Sci & Technol Tai An 271019 Peoples R China

The time-dependence bilinear mixed-regression deformation model and time-dependence bilinear dynamic system deformation model are established for deformation observation series. According to the multi- level recursive method, the time-dependence parameters are first traced and predicted, and then the dynamic system states. Due to the method considering time-dependence of deformation and having stronger adaptability to time-dependence system, it can improve forecast’s precision. It is very effective for data processing of nonlinear dynamic deformation monitoring to make multi-step forecasting.

关键词： multi-level recursive dynamic monitoring timedependence parameters

Interactions between hotspots and the Southwest Indian Ridge during the last 90 Ma:Implications on the formation of oceanic plateaus and intra-plate seamounts

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Science china Earth Sciences 2011年第8期54卷 1177-1188页

作者： ZHANG Tao 1,2.3,4,LIN Jian 5 & GAO JinYao 3,4 1 institute of geodesy and {2.,chinese academy of Sciences,Wuhan 430077,china 2.Graduate University of chinese academy of Sciences,Beijing 100049,china 3 The Second institute of Oceanography,State Oceanic Administrator,Hangzhou 310012.china 4 Key Laboratory of Submarine Geosciences,State Oceanic Administrator,Hangzhou 310012.china 5 Department of Geology and {2.,Woods Hole Oceanographic Institution,Woods Hole,MA 02.43,USA 1. institute of geodesy and {2. Chinese Academy of Sciences Wuhan 430077 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. The Second Institute of Oceanography State Oceanic Administrator Hangzhou 310012 China4. Key Laboratory of Submarine Geosciences State Oceanic Administrator Hangzhou 310012 China

This study investigates the relationship between the hotspot-ridge interaction and the formation of oceanic plateaus and seamounts in the Southwest Indian *** first calculated the relative distance between the Southwest Indian Ridge (SWIR) and relevant hotspots on the basis of models of plate reconstruction,and then calculated the corresponding excess magmatic anomalies of the hotspots on the basis of residual bathymetry and Airy *** results reveal that the activities of the Marion hotspot can be divided into three main phases:interaction with the paleo-Rodrigues triple junction (73.6-68.5 Ma),interaction with the SWIR (68.5-42.7 Ma),and intra-plate volcanism (42.7-0 Ma).These three phases correspond to the formation of the eastern,central,and western parts of the Del Cano Rise,*** magnitude and apparent periodicity of the magmatic volume flux of the Marion hotspot appear to be dominated by the hotspot-ridge *** periodicity of the Marion hotspot is about 2. Ma,which is much longer than that of the Hawaii and Iceland hotspots (about 15 Ma).

关键词： Southwest Indian Ocean hotspot-ridge interaction magmatic volume flux oceanic plateaus seamounts

Cold Thermal Anomalous Structure within Lower Mantle and Its Geodynamic Implications

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Journal of china University of Geosciences 2001年第2期12卷 160-164页

作者： Xiong Xiong institute of geodesy and {2., chinese academy of Sciences, Wuhan 430077 institute of Geology and {2., chinese academy of Sciences, Beijing 100101 Hsu Houtze institute of geodesy and {2., chinese academy of Sciences institute of geodesy and {2. Chinese Academy of Sciences institute of Geology and geophysics Chinese Academy of Sciences

The lateral temperature anomalous structure of the lower mantle is reconstructed from the seismic tomographical model and high temperature and high pressure laboratory results. A significant correlation between the distribution of the cold anomaly and the location of past subduction belts shows that the shallower anomaly corresponds to the younger subduction sites, while the deeper anomaly to the older ones. This correlation also suggests that the cold anomaly may have come from the subduction slabs and the scale of mantle convection may have been completed. The coldest and largest anomaly is concentrated near the core mantle boundary (CMB). Few cold anomalies float in the shallower and middle parts of the lower mantle, suggesting that the downward migration of the subduction slabs, discontinuous and step like, may be divided into the following three stages: subduction, stagnation at the 670 km discontinuity due to the phase transition, and disintegration when the size exceeds the critical point.

关键词： lower mantle cold thermal anomaly geodynamic implication.

APPLICATION OF ANALYTIC HIERARCHY PROCESS TO ASSESSING THE ECOLOGICAL VULNERABILITY OF WETLANDS IN THE JIANGHAN PLAIN

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chinese Geographical Science 2003年第3期13卷 272-276页

作者： WANG Xue-lei, NING Long-mei, HU Wang-bin(institute of geodesy and {2., chinese academy of Sciences, Wuhan 430077, P. R. china) institute of geodesy and {2. Chinese Academy of Sciences Wuhan P. R. China

Wetlands in the Jianghan Plain are important components of wetland types in lake area in the middle and lower reaches the Changjiang (Yangtze) River and they fulfill many uses and functions related to hydrology, waste assimilation, ecosystem productivity and biodiversity. Owing to natural factors and human activities, especially excessive reclamation from lakes, the shrinking process of the lakes has been accelerated. Wetland ecosystem has shown the characteristics of vulnerability. According to the analysis of wetland ecological function in the Jianghan Plain, this paper presented an index system related to productivity, stability and environmental capacity. By using the method of Analytic Hierarchy Process, we computed the values of the relative weights of the indexes, and evaluated the vulnerability level of the wetland ecosystem by the method of multi-indexes. The case study showed that the fragile extent of wetland ecosystem in the Jianghan Plain is 5.6. This means that the wetland ecosystem in the Jianghan Plain is laid to the state of middle vulnerability. Therefore, the wetland conservation and eco-rehabilitation in the Jianghan Plain should be paid attention to.

关键词： wetland ecological vulnerability AHP the jianghan plain

Time Series Correlated Error's Simulation Scheme with the Application to Simulate the Ephemerides Error of CHAMP

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测绘学报 2002年第Z1期31卷 27-30页

作者： SHEN Yun zhong 1 , HSU Hou tse 2.(1. Department of Surveying and Geo informatics,Tongji University,Shanghai 2.0092.china 2. institute of {2. and geophysics, CAS, Wuhan 430077,china) Department of Surveying and Geo-informatics Tongji University 上海 200092 Wuhan 430077

Computer simulation experiment is very important in the phase of project design, the availability of simulated result highly depends on the scheme of error simulation. Time series observations are normally correlated. This paper first discusses the formula of correlated error propagation, then derives the formula of simulating time series correlated errors. This formula is then used to simulate correlated ephemerides errors of CHAMP, then the ephemerides are used to recover the gravity vector at satellite altitude with finite differential formula. The formulae derived in this paper are verified with the difference between the recovered gravity vectors and the `true values’ which are directly computed with the same gravity model as that generating the ephemerides.

关键词： time series observation simulation of correlated errors CHAMP ephemerides

Optimal carrier-smoothed-code algorithm for dual-frequency GPS data

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Progress in Natural Science:Materials International 2008年第5期18卷 591-594页

作者： Jianfeng Guo a,b, Jikun Ou a, Yunbin Yuan a, Haitao Wang a a Key Laboratory of Geodynamics, institute of geodesy and {2., chinese academy of Sciences, Wuhan 430077, china b institute of Science, Information Engineering University, Zhengzhou 450001, china Key Laboratory of Geodynamics Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China institute of Science Information Engineering University Zhengzhou 450001 China

Carrier-smoothed-code (CSC) algorithm is an e ective pseudorange multipath mitigation technique, which can alleviate the compu- tational burden and reduce the communication bandwidth needed for the transmission of GPS observations. This paper presents an improved Hatch lter and addresses the optimal CSC algorithm for dual-frequency GPS data based on the optimal parameter estimation theory. The smoothed observations have the same information content as that of the raw dual-frequency GPS data from which these are derived. Consequently, the optimal CSC algorithm is equivalent to the uncombined algorithm. Theoretical analyses show that the data precision of the optimal CSC algorithm is better than that of Hatch lter and its improved version.

关键词： GPS Carrier-smoothed-code algorithm Hatch lter Time-invariant combinations

Experimental earth tidal models in considering nearly diurnal free wobble of the Earth's liquid core

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Science Bulletin 2003年第9期48卷 935-940页

作者： SUN Heping, XU Jianqiao & B. Ducarme Key Laboratory of Dynamic geodesy, institute of geodesy and geophysics, chinese academy of Sciences, Wuhan 430077, china Observatoire Royal de Belgique, Av. Circulaire 3, B-1180, Brussels, Belgium Correspondence should be addressed to Sun Heping (e-mail: heping@ ***) 1. Key Laboratory of Dynamic geodesy Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China 2. Observatoire Royal de Belgique}{srAv. Circulaire 3 B-1180 Brussels Belgium

Based on the 2. series of the high precision and high minute sampling tidal gravity observations at 2. stations in Global Geodynamics Project (GGP) network, the resonant parameters of the Earth's nearly diurnal free wobble (including the eigenperiods, resonant strengths and quality factots) are precisely determined. The discrepancy of the eigenperiod between observed and theoretical values is studied, the important conclusion that the real dynamic ellipticity of the liquid core is about 5% larger than the one under the static equilibrium assumption is approved by using our gravity technique. The experimental Earth's tidal gravity models with considering the nearly diurnal free wobble of the Earth's liquid core are constructed in this study. The numerical results show that the difference among three experimental models is less than 0.1%, and the largest discrepancy compared to those widely used nowdays given by Dehant (1999) and Mathews (2.01) is only about 0.4%. It can provide with the most recent real

关键词： Earth’s nearly diurnal free wobble global observations of superconducting gravimeters dynamic ellipticity of liquid core experimental earth tidal models.

Wetland vegetation biomass estimation and mapping from Landsat ETM data: a case study of Poyang Lake

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Journal of Geographical Sciences 2002年第1期12卷 35-41页

作者： LI Ren-dong1, 2. LIU Ji-yuan2.(1. institute of geodesy and {2., CAS, Wuhan 430077, china 2. institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101 china) institute of geodesy and {2. CAS Wuhan China institute of Geographic Sciences and Natural Resources Research CAS Beijing China

Poyang Lake is the largest freshwater lake in china. This paper conducted a digital and rapid investigation of the lake’s wetland vegetation biomass using Landsat ETM data acquired on April 16, 2.00. First, utilizing the false color composite derived from the ETM data as one of the main references, the authors designed a reasonable sampling route for field measurement of the biomass, and carried it out on April 18–2., 2.00. Then after both the sampling data and the ETM data were geometrically corrected to an equal-area projection of Albers, linear relationships among the sampling data and some transformed data derived from the ETM data and the ETM 4 were calculated. The results show that the sampling data is best relative to the band 4 data with a high correlation coefficient of 0.86, followed by the DVI and NDVI data with 0.83 and 0.80 respectively. Therefore, a linear regression model, which was based on the field data and band 4 data, was used to estimate the total biomass of entire Poyang Lake, and then the map of the biomass distribution was compiled.

关键词： Poyang Lake biomass wetland vegetation Landsat ETM data