Results 231 to 240 of about 96,005 (268)

Structure and Dynamics of Earth's Lower Mantle

Science, 2008
Processes within the lowest several hundred kilometers of Earth's rocky mantle play a critical role in the evolution of the planet. Understanding Earth's lower mantle requires putting recent seismic and mineral physics discoveries into a self-consistent, geodynamically feasible context.
Edward J, Garnero, Allen K, McNamara
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Upper mantle heterogeneities and dynamics

Nature, 1985
The width of geochemical and residual elevation anomalies along the Mid-Ocean Ridge System decrease as both the distance between migrating ridge segments and related hotspots and the local geochemical dispersion in the anomalies increase. These observations provide further evidence that flows of mantle plumes in the upper mantle are deflected by ...
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Mantle Dynamics – A Case Study

2009
Solid state convection in the rocky mantles is a key to understanding the thermochemical evolution and tectonics of terrestrial planets and moons. It is driven by internal heat and can be described by a system of coupled partial differential equations.
Gottschaldt, Klaus, Walzer, U., Stegman, D.R., Baumgardner, J.R., Muhlhaus, Hans B.   +4 more
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The dynamic mantle

1993
So far, the mantle has been described largely as if it were static; we have been answering questions such as: What is it made of? What changes across the seismic discontinuities? but not: What processes are operating?
G. C. Brown, A. E. Mussett
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State-dependent dynamics of cuttlefish mantle activity

Journal of Experimental Biology, 2023
ABSTRACTCuttlefish skin is a powerful rendering device, capable of producing extraordinary changes in visual appearance over a broad range of temporal scales. This unique ability is typically associated with camouflage, however cuttlefish often produce skin patterns that do not appear connected with the surrounding environment, such as fast large-scale
Sophie Cohen-Bodénès, Peter Neri
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Dynamic implications of mantle hotspots

Nature, 1974
MOVEMENT of lithosphere plates over hotspots which are fixed relative to the mantle could explain the origin of island chains and aseismic ridges1–4. Observations of phase velocities against epicentral distances for Tonga–Samoa earthquakes5 show anomalies which can be interpreted as a radial and lateral inhomogeneity in the lower mantle beneath Hawaii.
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Mantle dynamics and seismic anisotropy

Earth and Planetary Science Letters, 2010
Abstract Observations of seismic anisotropy yield some of the most direct constraints available on both past and present-day deformation in the Earth's mantle. Insight into the character of mantle flow can also be gained from the geodynamical modeling of mantle processes on both global and regional scales.
Maureen D. Long, Thorsten W. Becker
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Mantle dynamics and basalt petrogenesis

Tectonophysics, 1985
Abstract Differentiation at mid-ocean ridges generates a layered lithosphere consisting of a basaltic crust, immediately underlain by harzburgite and further underlain by pyrolite which has experienced depletion only of highly incompatible elements. The body forces driving subduction are concentrated mainly in the upper half of the lithosphere which ...
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Archean cratons and mantle dynamics

Earth and Planetary Science Letters, 2005
Abstract The apparent stability of Archean cratons and cratonic keels for billions of years is a difficult observation for geodynamic modeling to explain. While it may be straight-forward to assert that chemical buoyancy and high viscosity are needed to stabilize cratons, there are many questions regarding craton formation, variability (both in space
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Phase transformations and mantle dynamics

Earth and Planetary Science Letters, 1972
Abstract Major phase transitions occur in the normal mantle at depths near 400 and 650 km accompanied by density changes of 8–10 percent. The temperature gradients of the transitions are probably positive and in the vicinity of 20–30 bars/°C. The influence of these transitions upon the mantle engine which transports lithosphere plates is discussed ...
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