Revised determination of the paleointensity in the cretaceous from the collection of A.S. Bol’shakov and G.M. Solodovnikov

A large volume of data on the paleointensity H _an obtained by A.S. Bol’shakov and G.M. Solodovnikov is ignored in modern reconstructions because the authors did not indicate whether they used the check-point procedure for the detection of chemical alterations in rocks associated with determination of H _an. The paper presents new values of H _an determined by the Thellier-Coe method with the use of the checkpoint procedure from samples of the Armenian collection of Cretaceous rocks used in published studies of Bol’shakov and Solodovnikov. The new results are close to the published ones and point to a small value of the geomagnetic field in the Cretaceous, thereby corroborating Bol’shakov-Solodovnikov’s hypothesis on a low paleofield in the Mesozoic. Our study of samples of the collection studied confirms the reliability of Bol’shakov-Solodovnikov’s determinations of H _an.     

Physics of Seismic Source Ⅱ. Mechanics of Seismic Source

An earthquake is regarded as a fracture from the viewpoint of continuum mechanics, in which stress and strain play key roles in understanding the nature of a seismic source. This review briefly outlines the mechanics of a seismic source in terms of the dislocation model and crack model. The introduction includes the Coulomb failure criterion, static stress drop, dynamic stress drop, the Griffith criterion, and the scaling of source parameters. The selection of topics in the introduction emphasizes the application of seismic data, i.e., in practice, the mechanical parameters introduced here are measurable in the interpretation and analysis of seismic waveform data.     

International Journal of Sediment Research Index of Vol. 17

I. Soil erosion and sediment yield Upland Erosion Modeling with CASC2D-SED Pierre JULIEN and Rosal韆 ROJAS (No. 4, pp. 265-274) Effects of Soil Crusting on Soil Moisture, Runoff and Erosion: Field Observations Tongxin ZHU (No. 4, pp. 298-303) II. Environmental and ecological sedimentation Numerical Study on Environmental Impacts of the Third Shanghai Sewerage Project Cheng LIU, Huiran WANG, Y…     

International Journal of Sediment Research Index of Vol. 16

I. Soil erosion and sediment yieldDevelopment of Soil Erosion Index Model in Taiwan WatershedsVol. 16, No. 1, pp. 80-90 Modeling of Sediment Yield and Nonpoint Source Pollutant YieldVol. 16, No. 3, pp. 416-420 Runoff Generation Characteristics in Typical Erosion Regions on the Loess PlateauVol. 16, No. 4, pp. 473-485II. Environmental and ecological sedimentationLong Term Effects of Rehabilitation Measures on Bed Load Transport at the Salzach River Vol. 16, No. 2, pp. 95-102 Th…     

International Journal of Sediment Research Index of Vol. 19

1. Soil erosion and sediment yieldAssessment of Soil Loss on Uncultivated Slope Land by Using 137Cs Techniquein the Upper Yangtze River Basin of China Mingyi FENG, Xinbao ZHANG, Anbang WEN and Xiubin HE (No. 1, pp. 60-65)Evaluation of Erosion Productivity Impact Calculator (EDIC) Model forMIDDLE Mountain Region of Nepal Sohan Kumar GHIMRE and Mukand Singh BABEL (No. 2, pp. 106-122)Rill Ero…     

International Journal of Sediment Research Index of Vol. 20

I. Soil Erosion and Sediment Yield Downslope Erosion Process under Upslope Runoff and Sediment Using a Dual-Box System Peiqing Xiao, Fenli Zheng and Wenyi Yao (No. 2, pp. 136-142) Modeling Ephemeral Gully Erosion for Conservation Planning George R. FOSTER (No. 3, pp. 157-175) Hydrologically Driven Mechanisms of Headcut Development M. J. M. R?MKENS and S. N. PRASAD (No. 3, pp. 176-184) Numerical Simulation of Head-cut with a Two-layered Bed Yafei JIA, Tadanori KITAM…     

Physics of Seismic Source Ⅲ. Statistical Mechanics of Earthquakes

The statistical mechanics of earthquakes adopts the concepts and methodology of statistical mechanics, especially the theory of critical phenomena, in studying the preparation, initiation, propagation and healing of earthquake rupture, which forms a new branch in the physics of seismic source in recent years. This article introduces to the fundamental concepts of the statistical mechanics of earthquakes. The introduction includes the seismic Hamiltonian, percolation model, earthquake rupture nucleation, and Burridge-Knopoff spring-block model. It is pointed out that some of the statistical mechanical models of earthquakes have a sound seismological basis. There is a smooth "transition" from the "classical" theory to the "modern" theory of seismic source.     

Brief Introduction of NUCTECH CO. LTD

NUCTECH is a worldwide leading company specialized in research & development of x-ray inspection technology, as well as system design, manufacture, engineering and customer service. With the radiation imaging technology as its core competence, NUCTECH founded in July 1997, is a prestigious high-tech company originated from Tsinghua University. NUCTECH has developed and produced the THSCANTM Container/Vehicle Inspection Systems with linear accelerators, the Air Cargo/Vehicle Sec…     

In-plane–out-of-plane non-linear model of masonry infills in the seismic analysis of r.c.-framed buildings

The out-of-plane (OOP) behaviour of masonry infills (MIs), inserted in reinforced concrete (r.c.)–framed buildings, is recognized as one of the most important failure modes of this nonstructural element during an earthquake, which may be a consequence of simultaneous or prior in-plane (IP) damage. A five-element macro-model, with four diagonal OOP non-linear beams and one horizontal IP non-linear truss, with an equivalent mass of the infill panel divided between two central nodes, takes into account the IP and OOP failure modes occurring in the event of seismic loading. Pivot hysteretic models predict the non-linear IP and OOP force-displacement laws of the infill panel, based on geometrical rules defining loading and unloading branches. Firstly, a calibration of the proposed IP-OOP interaction model of MIs is carried out considering full-scale experimental results of traditional masonry typologies. Each specimen is initially subjected to in-plane quasi-static cyclic loading, until a maximum drift is reached, and then one-sided OOP cycles are imposed pushing in the horizontal direction and back to zero force. Then a numerical investigation considers masonry infills of an existing six-storey r.c.-framed building designed in compliance with a former Italian seismic code. To evaluate the interaction, the results of simultaneous IP and OOP cyclic tests on MIs at the top, intermediate, and lowest levels of the test structure are presented, assuming different displacement histories: (1) OOP loading faster than IP, at the sixth storey; (2) equal IP and OOP loading, at the third storey; (3) IP loading faster than OOP, at the first storey. Finally, attention is focused on the contribution of masonry infills to the IP and OOP energy dissipation of r.c.-framed structures.     

In memory of G.P. Kalinin (1916–1975)

Chronicles

In memory of G.P. Kalinin (1916–1975)     

A review of: “Problems of Solar and Stellar Oscillations. Iau Colloquium No. 66. Edited by D. O. Gough. D. Reidel Publishing Company, 493 pp. Df1195.00/U.S. $84.50 (ISBN 90-277-1554-8). 1983.”

Abstract

The model equations describing two-dimensional thermohaline convection of a Boussinesq fluid in a rotating horizontal layer are known to support multiple instabilities, depending on the values of certain control parameters (Arneodo et al., 1985). Most of these multiple instabilities have already been studied for double or triple diffusive convection, where behaviours ranging from simple steady to irregular motions have been found. Here we consider the one remaining bifurcation mentioned by Arneodo et al. (1985): the interaction between a steady and an oscillatory convection roll when the linear spectrum for a single wavenumber comprises one zero and one pair of purely imaginary eigenvalues. The method of centre manifolds and normal forms is used to derive evolution equations for the amplitudes of the convection rolls close to bifurcation and the behaviours associated with the equations is discussed.     

Deep Structure of the Swiss Alps,Results of NRP 20. Edited by O. A. Pfiffner,P. Lehner,P Heitzmann,St. Müller and A. Steck,Birkhauser Verlag,Basel 1997, 380pp.

Studia Geophysica et Geodaetica -