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Terrestrial and Lunar Magmatism: An Evolutionary Overview
Published in O.A. Bogatikov, R.F. Fursenko, G.V. Lazareva, E.A. Miloradovskaya, A. Ya, R.E. Sorkina, Magmatism and Geodynamics Terrestrial Magmatism Throughout the Earth’s History, 2020
E.V. Sharkov, O.A. Bogatikov, V.I. Kovalenko
According to the classical concept of plate tectonics, the geodynamics of the modern Earth’s surface can be explained by ocean-floor spreading, with further subduction of the surplus material in subduction zones. However, this is not so much new crust accreting in oceanic spreading centres, as the uprising and spreading of huge masses of heated low-density ultramafic material moving apart major blocks of ancient, cooled continental lithosphere towards the less viscous oceanic lithosphere of the Pacific Ocean. From this standpoint, mid-oceanic ridges appear to represent zones for the release of the main thermal–elestic stresses below large asthenospheric rises. Within their boundaries, oceanic-floor spreading actually reflects the main stages in the evolution of oceanic lithosphere, but is not a basis for processes occurring there.
On torsional wave in void type porous layers between viscoelastic and piezoelectric media with parabolic irregularity
Published in Waves in Random and Complex Media, 2023
Pato Kumari, Rupali Srivastava
The mathematical models regarding surface wave propagation have become a significant area of research for many researchers because of their wide range of applications in the fields of seismology, geophysics, earthquake engineering, geodynamics, etc. Surface waves are said to be the most destructive sort of seismic waves majorly responsible for earthquake damage resulting in immense loss of properties and lives. Torsional waves, one of surface waves, are also called twisting waves because of their ability to twirl the layered media through which they propagate. Torsional wave propagation in different elastic media has been scrutinized by many researchers, such as Wang [1], Dey et al. [2], Saha et al. [3], Selim [4], Chattopadhyay et al. [5], Rakshit et al. [6], Singh and Sahu [7], Prasad and Kundu [8], Manna et al. [9], and many more.
Rayleigh surface wave at an impedance boundary of an incompressible micropolar solid half-space
Published in Mechanics of Advanced Materials and Structures, 2022
Surface waves have been very crucial in various engineering fields including the earthquake engineering, seismology, geophysical explorations and geodynamics. In comparison to body waves, the surface waves have slower attenuation energy and hence the Rayleigh waves are responsible for damaging the structure. These waves can easily sense the defects in the surface. Rayleigh waves have broad applications in material characterization and in exploring the structural and mechanical properties of the objects. Lord Rayleigh [21] have investigated a type of surface waves for an isotropic elastic solid whose propagation is confined to the surface. Eringen [2] has obtained the frequency equation of Rayleigh surface waves in micropolar elastic half space along a stress free boundary. Surface waves in the theory of micropolar elasticity have also been studied in various models by many other researchers [22–37].
Response of a semiconducting medium under photothermal theory due to moving load velocity
Published in Waves in Random and Complex Media, 2022
It is observed that the magnitude of moving load velocity and thermoelectric coupling parameter plays a significant role in the deformation of a solid. The effect of moving load velocity is more significant than the effect of the thermoelectric coupling constant.The values of normal displacement and normal force stress for lie in a short-range.The variations of all the quantities are more oscillatory in nature near the point of application of source, which justifies that the effect of moving load slows down with horizontal distance.The problem finds its applications in various dynamical systems like earthquake engineering, highway engineering, geodynamics, etc.