Zheng-Qin He  Tai-Lan Ye  Wei-Guo Sun 《地震学报(英文版)》1996,9(1):127-133

Based on the long period surface wave data recorded by the China Digital Seismograph Network (CDSN), theQ _R of fundamental mode Rayleigh wave with periods from 10 s to 146 s is determined for the eastern Sino-Korean paraplatform in this paper. TheQ _β models of the crust and upper mantle are respectively obtained for the 4 paths, with the aid of stochastic inverse method. It shows that in the eastern Sino-Korean paraplatform, the average crustalQ _β is about 200, and that there exists a weak attenuation layer in the middle crust (about 10–20 km deep) which is possibly related to earthquake-prone layer. A strong attenuation layer (lowQ) of 70 km thick extensively exists in the uppermost mantle, with the buried depth about 80 km. The averageQ _R of fundamental mode Rayleigh wave is between the value of stable tectonic region and that of active tectonic region, and much close to the latter. Contribution No. 96A0001, Institute of Geophysics, SSB, China. Funded by the Chinese Joint Seismological Science Foundation.  相似文献   

Modifications of the dispersion relations for surface waves in a layer on a half-space     

Oldřich Novotný  L. V. Burlako  T. A. Proskuryakova 《Studia Geophysica et Geodaetica》1996,40(2):167-177

Summary Dispersion relations for Love and Rayleigh waves in a layer on a half-space are modified by introducing quadratic slownesses instead of velocities. The advantages of this approach are demonstrated on analytical formulae for computing the group velocity.  相似文献   

Stochastic sketching of infiltration-advance isochrones     

W. O. Rasmussen 《Stochastic Environmental Research and Risk Assessment (SERRA)》1996,10(3):209-229

A technique has been developed for predicting the irregular advance pattern often observed as water spreads on the surface of the ground. The technique is a combination of stochastic sketching, potential theory, probability theory, and a mass balance equation in the form of an advance equation. The technique can be used on flat as well as sloping terrain and addresses any form of obstructions or constraints to the flow of the water. The stochastic sketching portion of the technique uses cellular automata with transition probability movement rules to sketch the dynamics of small volume water elements in the defined environment. Randomly selected small volume flow path segments are computed and plotted. The envelope of these segments defines the wetted area and the advance front. Several examples are presented showing the patterns produced for various situations.  相似文献   

From surface electrical properties to spontaneous potentials in porous media   总被引：1，自引：0，他引：1  

A. Revil  M. Darot  P. A. Pezard 《Surveys in Geophysics》1996,17(3):331-346

This paper deals with the electrical double layer and the related properties of porous media. In particular, the electrical conductivity, the streaming potential, and the membrane potential are described in a self-consistent set of equations. All these properties are shown to be governed by fluid-matrix interface properties, as well as four geometrical parameters.  相似文献   

Thermal convection in a cylindrical annulus with a non-Newtonian outer surface     

Stuart A. Weinstein 《Pure and Applied Geophysics》1996,146(3-4):551-572

This study presents the results of numerical simulations of a model for lithospheremantle coupling in a terrestrial type planet. To first order, a geologically active terrestrial type planet may consist of a metallic core, silicate mantle and lithosphere, with the lithosphere being rheologically different from the mantle. Therefore we have developed a numerical model consisting of a thin non-Newtonian fluid hoop that is dynamically coupled to a thick Newtonian fluid cylindrical annulus. Thus the rheological dichotomy between mantle and lithosphere is built into the model. Time-dependent calculations show the existence of at least two regimes of behaviors. In one regime, the behavior of the hoop switches between periods characterized by low or high speeds, in response to changes in convective vigor and planform. This regime may apply to the planet Venus where the available evidence indicates that prior to 500 myr ago, the planet was resurfaced on a time scale of <100 myr. Since that time, large-scale tectonic activity on Venus has been sharply curtailed. In the other regime, which is more like plate tectonics on Earth, the hoop speeds rise and fall on short time scales.  相似文献   

    

Li Yang  Mu Mu 《大气科学进展》1996,13(1):33-42

By employing Arnol’d’s method (energy-Casimir), this paper has studied the nonlinear stability of the two-layer generalized Phillips’ model for which the top and bottom surfaces are either rigid or free, and obtained some nonlinear stability criteria. In addition, some linear stability criteria are obtained by normal mode method. The results reveal the influences of the free surface parameter on the stability of atmospheric and oceanic motions.  相似文献   

1988年反厄尼诺(La Niña)事件的数值模拟     

张荣华 《气象学报》1996,54(1):53-64

用中国科学院大气物理研究所高分辨率、自由表面热带海洋环流模式对厄尼诺/南方涛动(El/Southern Oscillation)循环中另一重要位相La Niña事件进行了数值模拟研究。模式区域为南北纬30°之间的热带太平洋,经纬圈水平方向分辨率分别为2°和1°,垂直方向分为不等距的14层;模式中考虑了盐度并引入与洋流切变和层结稳定度有关的垂直扩散参数化方案。在观测到的海表风应力、热量和淡水通量(蒸发与降水之差)驱动下,所发展的模式从1984年积分到1989年。本文给出模式对近十几年来最强的1988年La Niña事件进行数值模拟的结果,着重分析La Niña期间热带太平洋海面起伏、流场和温度场时空演变,以及La Niña和El期间变量场时空结构差别。文中还进行了模式结果和一些观测资料间的比较。  相似文献   

中国地表感热的气候计算及其分布          下载免费PDF全文

高庆先  翁笃鸣 《大气科学学报》1996,19(2):238-244

讨论了我国地表感热的气候计算问题,提出以鲍文比法为基础的感热气候计算式,并据此计算出全国215站月、年平均感热通量密度,进而分析了其在全国的时空分布特点。  相似文献   

StudyofCurieisothermalsurfaceinSichuanBasinandtheseismicareaonitswesternmar┐gin     

张先  虎喜凤  沈京秀  田长征 《地震学报(英文版)》1996,9(1):109-116

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Morphological characteristics of the earthquake surface ruptures on Awaji Island, associated with the 1995 Southern Hyogo Prefecture Earthquake   总被引：1，自引：0，他引：1  

Aiming  Ian Shinichi  Uda 《Island Arc》1996,5(1):1-15

Abstract The earthquake surface ruptures on the northern side of Awaji Island accompanying the 1995 Southern Hyogo Prefecture Earthquake in Japan consist of three earthquake surface rupture zones called the Nojima, Matsuho, and Kusumoto Earthquake Surface Rupture Zones. The Nojima Earthquake Surface Rupture Zone is - 18 km long and was formed from Awaji-cho at the northern end of Awaji Island to Ichinomiya-cho. It occurred along the pre-existing Nojima geological fault in the northern segment and as a new fault in the southern segment. The northern segment of the Nojima Earthquake Surface Rupture Zone is composed of some subparallel shear faults showing a right-step en echelon form and many extensional cracks showing a left-step en echelon form. The southern segment consists of some discontinuous surface ruptures which are concentrated in a narrow zone a few tens of meters in width. This surface rupture zone shows a general trend striking north 30°-60° east, and dipping 75°-85° east. The deformational topographies and striations on the fault plane generated during the co-seismic displacement show that the Nojima Earthquake Surface Rupture Zone is a right-lateral strike-slip fault with some reverse component. Displacements measured at many of the outcrops are generally 100-200 em horizontally and 50-100 em vertically in the northern segment and a few em to 20 em both horizontally and vertically in the southern segment. The largest displacements are 180 em horizontally, 130 em vertically, and 215 em in netslip measured at the Hirabayashi fault scarp. The Matsuho Earthquake Surface Rupture Zone striking north 40°-60° west was also found along the coastline trending northwest-southeast in Awaji-cho for ～1 km at the northern end of Awaji Island. The Kusumoto Earthquake Surface Rupture Zone occurred along the pre-existing Kusumoto geological fault for ～ 1.5 km near the northeastern coastline, generally striking north 35°-60° east, dipping 60°-70° west. From the morphological and geomorphological characteristics, the Nojima Earthquake Surface Rupture Zone can be divided into four segments which form a right-step en echelon formation. The geological and geomorphological evidence and the aftershock epicenter distributions show clearly that the distributions and geometry of these four segments are controlled by the pre-existing geological structures.  相似文献