台湾西部河口堆积形态之地形学研究

本研究以台湾西部３０个主次要河川的河口地区为研究对象，其河口堆积形态依堆积规模与位置，可概分为两岸沙洲型、左岸沙洲型、右岸沙洲型、没口沙洲型、扇状堆积型、宽阔滩面型及较少堆积型等七类。藉由定性比较与定量分析等方法，期以地形学的研究观点，达到了解河口地区地形特性、海陆交互作用与河口堆积形态之相关的目的，俾提供为河川下游平原开发利用之参考。     

Inversion of gravity and topography data for the crust thickness of China and its adjacent region

Introduction Since the middle of the century, gravitational isostasy has been a fundamental hypothesis for inverting the gravity data to find the crust thickness. Geophysicists have done a lot of researches on using gravity data to investigate the depth of Moho discontinuity. Since 1980, the International Lithosphere Program emphasized the importance of investigating the Moho depth variation. Thereafter a lot of results have been published in the world (Braitenberg et al, 2000; Kaban et al,…     

Effects of Integrated Exploration in Hydrocarbon-Prospective Areas of South China

The complicated topography, morphology and geology are characteristic of South China, where the frequently covered waters and igneous bodies and widely exposed carbonates are difficult to seismic survey. This paper describes the effect of combining exploration of gravitational, magnetic and electric methods in the complicated hydrocarbon areas in South China by some case histories. Many year‘‘s exploration practices in the exploring areas of more than 20 show that the non-seismic integrated (gravity/magnetic/electric) geophysical prospecting can play an important role not only in regional assessment, basin optimization and early basin evaluation,but also in finding objective of low resistance in areas of exposed carbonate with high resistance, contouring local structure, outlining igneous body and reef, and differentiating rock facies of basement. The results of the non-seismic integrated geophysical survey have pointed out the direction for deploying next prospecting in the specific areas of South China and the valuable experiences have been accumulated to carry out hydrocarbon-hunting in the future.     

Topographical Correction on Gravity Data in Complex Mountainous Areas

Discussed in this paper was the pre-processing procedure for gravity data, including topographical correction,intermediary layer correction etc. The necessity to utilize aerial photogram to do topographical correction in middle area was discussed, and a real examples given showing the effect. We discussed the problems caused by the maximum radius for conventional correction, the necessity of extending the radius for topographical correction, the corresponding method for calculation of topographical correction, and the standard of optimally selecting the radium for topographical correction.This method could raise the data accuracy of gravity survey in the complex mountainous areas by several millil-gals-several tens milli-gals reaching the exploration effect as well as in plain area almost.     

Marine Active Fault Exploration and Paleoearthquake Research

Marine active fault exploration and Paleoearthquake research are still a gap in China.The paper gives a review on major research methods and new progress made abroad,including submarine survey boat.seismic reflection and acoustic reflection.Through detailed studies of offset history of 10 ka to 30ka,it is possible to determine paleoearthquake recurrent intervals and elapsed time since last major earthquake.It is suggested that active fault exploration can be carried out by acoustic exploring method in large earthquake region of Bohai Sea.Paleoearthquake activity history can be revealed and earthquake risk in the future can be predicted.     

地理环境是进行战争的依据和基础

本文通过实际战例,论述了地理环境对国防建设和战争的影响;论述了地理环境与指挥员决策的关系以及军事地理学与军事地形学之间的任务分工、区别和联系;最后对如何加强我军军事地理学教育、增大军事地理学训练面提出了建议。     

Calculation of circulation in the South China Sea during summer of 2000 by the modified inverse method

On the basis of hydrographic data obtained in August 2000 cruise, the circulation in the South China Sea (SCS) is computed by the modified inverse method in combination with SSH data from TOPEX/ERS-2 analysis. For study of the dynamical mechanism, which causes the pattern of summer circulation in the SCS, the diagnostic model (Yuan et al. 1982. Acta Oceanologica Sinica,4(1):1-11; Yuan and Su. 1992. Numerical Computation of Physical Oceanography.474-542) is used to simulate numerically the summer circulation in the SCS. The following results     

Topography, exhumation, and drainage network evolution of the Apennines

The present-day topography of the Italian peninsula results from the interactions between crustal-mantle and surface processes occurring since the Late Miocene. Analysis of exhumation and cooling of crustal rocks, together with Quaternary drainage evolution,helps to unravel the tectonic-morphologic evolution of the Apennines by distinguishing end-member models,and hence describing the orogenic belt evolution. The pattern of regional topography, erosional history and present-day distribution of active deformation suggests that the eastward migrating extensional-compressional paired deformation belts may still control the topogra-phy of the northern Apennines, albeit at slower rates than in the past. Conversely, Quaternary drainage evo-lution in the central and southern Apennines suggests that the topography of these regions underwent a Quaternary regional arching, which is only partly con-sistent with the persisting migration of the compres-sional-extensional pair.     

Application of Multifocusing Method for an Irregular Topography Imaging

INTRODUCTION Astackofrecordedseismicdatabecomesoneof themainstepsinmoderndataprocessingwhenmulti foldacquisitionsystemsaretheleadingmethodof collectingseismicdata.Inthestackprocedure,the crucialoperationistimecorrection.Anaccurateand reliabletraveltimemoveoutcorrectionformulaisnec essaryinordertodostackproperly(Gelchinskyet al.,1999a).Themostfamousmoveoutexpressionis thenormalanddipmoveout(NMO/DMO)designed todescribethetraveltimeofprimaryreflectionsof common midpoint(CMP)data.Beingdes…