Stress Changes Induced by Earthquakes and Secular Stress Accumulation in the Buller Region,South Island,New Zealand (1929–2002)     

Jaime O.?Hincapie  Diane I.?DoserEmail author  Russell?Robinson 《Pure and Applied Geophysics》2005,162(2):291-310

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Ground water whirls     

Hemker K  van den Berg E  Bakker M 《Ground water》2004,42(2):234-242

Numerical experiments with steady-state ground water flow models show that spiraling flow lines occur in layered aquifers that have different anisotropic horizontal hydraulic conductivities in adjacent layers. Bundles of such flow lines turning in the same direction can be referred to as ground water whirls. An anisotropic layered block in a field of uniform horizontal flow results in one or more whirls with their axes in the uniform flow direction. The number of whirls depends on the number of interfaces between layers with different anisotropic properties. For flow to a well in an aquifer consisting of two anisotropic layers, with perpendicular major principal directions, whirls are found to occur in quadrants that are bounded by the principal directions of the hydraulic conductivity. The combined effect of flow to a well and a layered anisotropy implies that a single well in a system with a single anisotropic layer within an otherwise isotropic aquifer causes eight whirls. All adjacent whirls rotate in opposite directions.  相似文献   

IMPROVED PREDICTIONS OF ELECTRIC FIELD STRENGTHS AND VOLUME EMISSIVITIES IN SECOND HARMONIC TYPE III SOLAR RADIO EMISSION     

Willes  A. J.  Robinson  P. A. 《Solar physics》1997,170(2):341-356

Previous comparisons between predicted and observed electric field strengths and volume emissivities in second harmonic type III solar radio emission are improved in two ways. First, the assumption of the head-on approximation in deriving the harmonic emission rate, which is not applicable over the full range of observed type III parameters, is replaced with a more suitable approximation. Secondly, a more realistic functional form for the Langmuir wave spectra is adopted. The revised predicted electric field strengths and volume emissivities are consistent with the observed values.  相似文献   

Space Plasma Exploration by Active Radar (SPEAR): an overview of a future radar facility   总被引：1，自引：0，他引：1  

D. M. Wright  J. A. Davies  T. R. Robinson  P. J. Chapman  T. K. Yeoman  E. C. Thomas  M. Lester  S. W. H. Cowley  A. J. Stocker  R. B. Horne  F. Honary 《Annales Geophysicae》2000,18(9):1248-1255

SPEAR is a new polar cap HF radar facility which is to be deployed on Svalbard. The principal capabilities of SPEAR will include the generation of artificial plasma irregularities, operation as an all-sky HF radar, the excitation of ULF waves, and remote sounding of the magnetosphere. Operation of SPEAR in conjunction with the multitude of other instruments on Svalbard, including the EISCAT Svalbard radar, and the overlap of its extensive field-of-view with that of several of the HF radars in the SuperDARN network, will enable in-depth diagnosis of many geophysical and plasma phenomena associated with the cusp region and the substorm expansion phase. Moreover, its ability to produce artificial radar aurora will provide a means for the other instruments to undertake polar cap plasma physics experiments in a controlled manner. Another potential use of the facility is in field-line tagging experiments, for coordinated ground-satellite experiments. Here the scientific objectives of SPEAR are detailed, along with the proposed technical specifications of the system.  相似文献   

Stochastic wave growth, power balance, and beam evolution in type III solar radio sources     

P. A. Robinson 《Solar physics》1996,168(2):357-374

Energy-balance arguments are combined with the stochastic-growth theory of type III radio sources to determine the properties of the source in average dynamical equilibrium with the beam, and the beam's long-term evolution. Purely linear stochastic-growth theory has previously emphasized that the beam evolves to a state close to marginal stability. Small mean residual deviations from marginal stability are present at dynamical equilibrium and these lead to residual energy flows that feed the waves observed in situ and by remote receivers; consequently the beam energy is depleted. Here, dynamical equilibrium beam and wave levels are estimated for the first time and it is found that the main sink of beam-driven Langmuir waves is either via electrostatic decay into product Langmuir and ion-sound waves or via scattering by short-wavelength density fluctuations, depending on the conditions. Improved estimates of energy branching ratios imply that, at 1 AU from the Sun, typically 20% of the beam energy is converted to Langmuir waves that are scattered off low-frequency density fluctuations and then dissipated, with almost all the remaining waves undergoing electrostatic decay, although as little as one-third of the Langmuir waves may decay in atypical circumstances. Of order 10^–3 of the beam energy is converted into sound waves, which are mostly dissipated, and of order 10^–5 is converted into potentially observable electromagnetic waves. The mean lifetime of the Langmuir waves at 1 AU is 1–40 s, while that of the beam is of order 1000 s. The beam density decreases relative to that of the background as the beam propagates. For most parameters, analysis of energy losses from the beam to the waves shows that the beam velocity decreases at roughly the same rate as the thermal velocity of the background plasma. It is argued from these considerations, and from in situ observations at 1 AU, that these trends imply that only the densest and fastest type III beams will be able to penetrate much past 1 AU from the Sun. This implies a low-frequency cutoff to type III emission at roughly 10 kHz, in good agreement with recent Ulysses remote observations, showing their consistency with in situ measurements.  相似文献   

The restricted problem of three bodies with rigid dumb-bell satellite     

W. J. Robinson 《Celestial Mechanics and Dynamical Astronomy》1973,8(2):323-330

This paper is concerned with an extension of the classical restricted problem of three bodies in three dimensions. Usually, the satellite is considered to be a point mass. Here, the satellite is assumed to have a simple structure. The equations of motion are obtained and some of their consequences are discussed.  相似文献   

CATALOG OF THE COLLECTION OF METEORITES AT THE UNIVERSITY OF CALIFORNIA,LOS ANGELES (THE LEONARD COLLECTION)     

John T. Wasson  Edward R. D. Scott  Karen L. Robinson 《Meteoritics & planetary science》1974,9(1):85-98

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Velocity structure of the Wellington region, New Zealand, from local earthquake data and its implications for subduction tectonics     

Russell Robinson 《Geophysical Journal International》1983,75(2):335-359

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World fisheries to 2000: Supply,demand and management     

M.A. Robinson 《Marine Policy》1980,4(1):19-32

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AGRICULTURAL INNOVATION: THE EXAMPLE OF PEANUT-GROWING IN THE BELIZE VALLEY, CENTRAL AMERICA     

Guy M. Robinson  D.Phil. 《Singapore journal of tropical geography》1985,6(2):116-126

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