The long-wavelength geoid and topography are dynamic effects of a convecting mantle. The long-wavelength geoid of the Earth is controlled by density variations in the mantle and has been explained by circulation models involving whole mantle flow. However, the relationship of long-wavelength topography to mantle circulation has been a puzzling problem in geodynamics. We show that the dynamic to...

the electrical conductivity of the earth is its physical parameter, which can be studied in global scales. the investigations of the earth's electrical conductivity are based on geomagnetic field variations. time variations of the geomagnetic field consist of long-term and short-term (transient) variations. external sources induce electric currents into the earth. the induced electric curr...

Fundamental understanding of the goaf gas distribution in a gassy coal mine is necessary for developing effective goaf gas drainage strategies in the longwall coal mine. The goaf gas was subjected to the surface and body forces that were classified depending upon whether they acted on the surface area or the volume of the gas element. Of these forces, the body forces were more predominant in di...

Annual growth ring variations in Arctic trees are often used to reconstruct surface temperature. In general, however, the growth of Arctic vegetation is limited both by temperature and light availability, suggesting that variations in atmospheric transmissivity may also influence tree-ring characteristics. Here we show that Arctic tree-ring density is sensitive to changes in light availability ...

Interaction potentialsof rare gases withmetal surfaces are calculated and compared with experimental data. A local dielectric function formalism and the density functional method are used in the calculation of the attractive and repulsive energies respectively. Depth and curvature variations of the potentials suggest a classification into light (He, Ne) and heavy rare gases. Sensitivity of the ...

in this study variations of field data such as temperature, salinity and density in and across the transects of chahbahar bay were analyzed using ctd data acquired between winter 2006 and spring 2007 (winter monsoon).the results showed that thermocline layer intensify in mouth of bay between 2m and 6m with 7.81 ?c decrease before the gonou hurricane occured (mid-may 2007). below thermocline lay...