scholarly journals Quantizing Earth surface deformations

2015 ◽  
Vol 7 (1) ◽  
pp. 1059-1076
Author(s):  
C. O. Bowin ◽  
W. Yi ◽  
R. D. Rosson ◽  
T. S. Bolmer ◽  
W. J. Sass

Abstract. The global analysis of Bowin (2010) used the global 14 absolute Euler pole set (62 Myr history) from Gripp and Gordon (1990) and demonstrated that plate tectonics conserves angular momentum. We herein extend that analysis using the more detailed Bird (2003) 52 present-day Euler pole set (relative to a fixed Pacific plate) for the Earth's surface, after conversion to absolute Euler poles. Additionally, new analytical results now provide new details on upper mantle mass anomalies in the outer 200 km of the Earth, as well as an initial quantizing of surface deformations.

Author(s):  
David Vaughan

‘Minerals and the interior of the Earth’ looks at the role of minerals in plate tectonics during the processes of crystallization and melting. The size and range of minerals formed are dependent on the temperature and pressure of the magma during its movement through the crust. The evolution of the continental crust also involves granite formation and processes of metamorphism. Our understanding of the interior of the Earth is based on indirect evidence, mainly the study of earthquake waves. The Earth consists of concentric shells: a solid inner core; liquid outer core; a solid mantle divided into a lower mantle, a transition zone, and an upper mantle; and then the outer rigid lithosphere.


2020 ◽  
Author(s):  
Javier Fullea ◽  
Sergei Lebedev ◽  
Zdenek Martinec ◽  
Nicolas Celli

<p>The lateral and vertical thermochemical heterogeneity in the mantle is a long standing question in geodynamics. The forces that control mantle flow and therefore Plate Tectonics arise from the density and viscosity lateral and vertical variations. A common approach to estimate the density field for geodynamical purposes is to simply convert seismic tomography anomalies sometimes assuming constraints from mineral physics. Such converted density field does not match in general with the observed gravity field, typically predicting anomalies the amplitudes of which are too large. Knowledge on the lateral variations in lithospheric density is essential to understand the dynamic/residual isostatic components of the Earth’s topography linking deep and surface processes. The cooling of oceanic lithosphere, the bathymetry of mid oceanic ridges, the buoyancy and stability of continental cratons or the thermochemical structure of mantle plumes are all features central to Plate Tectonics that are dramatically related to mantle temperature and composition.</p><p><br>Conventional methods of seismic tomography, topography and gravity data analysis constrain distributions of seismic velocity and density at depth, all depending on temperature and composition of the rocks within the Earth. However, modelling and interpretation of multiple data sets provide a multifaceted image of the true thermochemical structure of the Earth that needs to be appropriately and consistently integrated. A simple combination of gravity, petrological and seismic models alone is insufficient due to the non-uniqueness and different sensitivities of these models, and the internal consistency relationships that must connect all the intermediate parameters describing the Earth involved. In fact, global Earth models based on different observables often lead to rather different, even contradictory images of the Earth.</p><p><br> Here we present a new global thermochemical model of the lithosphere-upper mantle (WINTERC-grav) constrained by state-of-the-art global waveform tomography, satellite gravity (geoid and gravity anomalies and gradiometric measurements from ESA's GOCE mission), surface elevation and heat flow data. WINTERC-grav is based upon an integrated geophysical-petrological approach where all relevant rock physical properties modelled (seismic velocities and density) are computed within a thermodynamically self-consistent framework allowing for a direct parameterization of the temperature and composition variables.</p>


Author(s):  
Sonia M. Tikoo ◽  
Linda T. Elkins-Tanton

The Earth is likely to have acquired most of its water during accretion. Internal heat of planetesimals by short-lived radioisotopes would have caused some water loss, but impacts into planetesimals were insufficiently energetic to produce further drying. Water is thought to be critical for the development of plate tectonics, because it lowers viscosities in the asthenosphere, enabling subduction. The following issue persists: if water is necessary for plate tectonics, but subduction itself hydrates the upper mantle, how is the upper mantle initially hydrated? The giant impacts of late accretion created magma lakes and oceans, which degassed during solidification to produce a heavy atmosphere. However, some water would have remained in the mantle, trapped within crystallographic defects in nominally anhydrous minerals. In this paper, we present models demonstrating that processes associated with magma ocean solidification and overturn may segregate sufficient quantities of water within the upper mantle to induce partial melting and produce a damp asthenosphere, thereby facilitating plate tectonics and, in turn, the habitability of Earth-like extrasolar planets. This article is part of the themed issue ‘The origin, history and role of water in the evolution of the inner Solar System’.


2003 ◽  
Vol 35 (4-5) ◽  
pp. 541-551 ◽  
Author(s):  
L.A. Latynina ◽  
I.M. Vasil'ev

2019 ◽  
Vol 56 (11) ◽  
pp. 1095-1100
Author(s):  
Wolf-Christian Dullo ◽  
Fritz A. Pfaffl

In his paper “Über das Bewegungsbild von Faltengebirgen” [On the movement pattern of folded mountains], published in the almanac of the Austrian Geological Survey in Vienna, Otto Ampferer from Innsbruck (Austria) presented a series of geotectonic considerations and interpretations, which today are summarized under the term “theory of undercurrent”. The interpretation of these processes occurring in the deep crust of the Earth and in the upper mantle was mainly kinematic. For a long time, the tectonic passivity of the magma being anorogenic was dogma until Ampferer’s undercurrent theory changed this in 1906, according to which folds and thrusts on the Earth’s surface portray motions of the deeper magmatic substratum. In these undercurrents, Ampferer recognized the crucial forces that lead to the formation of ocean basins and high mountains on the edges of the drifting continents. In his paper on the history of the formation of the Atlantic region, he presented already, in 1941, a process anticipating what is now known as seafloor spreading.


1997 ◽  
Vol 3 (3-4) ◽  
pp. 50-53
Author(s):  
O.D. Fedorovskyi ◽  
◽  
V.I. Kononov ◽  
K.Yu. Sukhanov ◽  
◽  
...  

2020 ◽  
Vol 42 (3) ◽  
pp. 271-282
Author(s):  
OLEG IVANOV

The general characteristics of planetary systems are described. Well-known heat sources of evolution are considered. A new type of heat source, variations of kinematic parameters in a dynamical system, is proposed. The inconsistency of the perovskite-post-perovskite heat model is proved. Calculations of inertia moments relative to the D boundary on the Earth are given. The 9 times difference allows us to claim that the sliding of the upper layers at the Earth's rotation speed variations emit heat by viscous friction.This heat is the basis of mantle convection and lithospheric plate tectonics.


Author(s):  
Yuuki UCHIDA ◽  
Tomohito ASAKA ◽  
Takashi NONAKA ◽  
Keishi IWASHITA ◽  
Toshiro SUGIMURA

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