Matches in SemOpenAlex for { <https://semopenalex.org/work/W2160117780> ?p ?o ?g. }
- W2160117780 endingPage "253" @default.
- W2160117780 startingPage "231" @default.
- W2160117780 abstract "Numerical simulations in both twoand three-dimensions are performed to investigate the hypothesis that D” is a thermo-chemical boundary layer. A layer of dense, compositionally-distinct material above the CMB reduces the characteristic horizontal lengthscales and interior mantle temperature. In three-dimensions, the layer forms a spoke pattern, with entrainment in upwelling cylinders, even for systems which are heated entirely from within. Long-term stability of the layer requires rather high density contrasts if the Boussinesq approximation is assumed, but geophysically reasonable density contrasts using a compressible formulation with depth-dependent properties. Temperature-dependent viscosity and internal heating also promote greater layer stability. Even if the core heat flux is zero, the layer can become several 100 K higher than the mantle above it, due to trapped radiogenicallyproduced heat. The combination of high deep-mantle viscosity and other depth-dependent parameters allows a stable layer with very high topography, leading to huge, thermo-chemical ‘megaplumes’ extending at least half way through the lower mantle. These stationary megaplumes are stable for long geological times and may correspond to the ‘megaplumes’ imaged tomographically under Africa and the Pacific, as well as acting as a geochemical reservoir and providing an explanation for various other geophysical observations. The dense layer increases the lateral heterogeneity in density and probably seismic velocity in the deep mantle, although the signature of the layer may be partly masked by cancellation of thermal and chemical effects. The interaction of thermal convection with a preexisting dense, homogeneous layer does not cause short-wavelength heterogeneity per se (although sharp edges may be generated), and thus some additional mechanism, such as the introduction of fresh heterogeneity by slabs, must be active to explain seismic observations of short-scale D” variation. Unfortunately, these mechanisms tend to produce a layer boundary too gradual to produce a strong seismic reflection, perhaps leading to a phase change as the prefered explanation of the “Lay discontinuity”." @default.
- W2160117780 created "2016-06-24" @default.
- W2160117780 creator A5060893488 @default.
- W2160117780 date "1998-01-01" @default.
- W2160117780 modified "2023-10-18" @default.
- W2160117780 title "Three-dimensional simulations of mantle convection with a thermo-chemical basal boundary layer: D″?" @default.
- W2160117780 cites W1496410283 @default.
- W2160117780 cites W1548568515 @default.
- W2160117780 cites W1964564528 @default.
- W2160117780 cites W1967932790 @default.
- W2160117780 cites W1968430874 @default.
- W2160117780 cites W1969599221 @default.
- W2160117780 cites W1971326714 @default.
- W2160117780 cites W1974932869 @default.
- W2160117780 cites W1975619655 @default.
- W2160117780 cites W1976391619 @default.
- W2160117780 cites W1985960100 @default.
- W2160117780 cites W1989809075 @default.
- W2160117780 cites W1991650472 @default.
- W2160117780 cites W1991868250 @default.
- W2160117780 cites W1997533864 @default.
- W2160117780 cites W1999394599 @default.
- W2160117780 cites W1999741397 @default.
- W2160117780 cites W2017218537 @default.
- W2160117780 cites W2019375842 @default.
- W2160117780 cites W202241982 @default.
- W2160117780 cites W2030715338 @default.
- W2160117780 cites W2034429059 @default.
- W2160117780 cites W2035096112 @default.
- W2160117780 cites W2035798381 @default.
- W2160117780 cites W2051189536 @default.
- W2160117780 cites W2051910146 @default.
- W2160117780 cites W2056884602 @default.
- W2160117780 cites W2060170567 @default.
- W2160117780 cites W2062221814 @default.
- W2160117780 cites W2070931811 @default.
- W2160117780 cites W2071118545 @default.
- W2160117780 cites W2073622137 @default.
- W2160117780 cites W2074618243 @default.
- W2160117780 cites W2075653325 @default.
- W2160117780 cites W2075842890 @default.
- W2160117780 cites W2079260131 @default.
- W2160117780 cites W2080851938 @default.
- W2160117780 cites W2083935149 @default.
- W2160117780 cites W2083989345 @default.
- W2160117780 cites W2084352787 @default.
- W2160117780 cites W2090331799 @default.
- W2160117780 cites W2090666753 @default.
- W2160117780 cites W2095840192 @default.
- W2160117780 cites W2097114968 @default.
- W2160117780 cites W2103543473 @default.
- W2160117780 cites W2103711815 @default.
- W2160117780 cites W2115914348 @default.
- W2160117780 cites W2116429925 @default.
- W2160117780 cites W2132767923 @default.
- W2160117780 cites W2133678997 @default.
- W2160117780 cites W2133754735 @default.
- W2160117780 cites W2133951519 @default.
- W2160117780 cites W2138424181 @default.
- W2160117780 cites W2149057440 @default.
- W2160117780 cites W2152765686 @default.
- W2160117780 cites W2166696820 @default.
- W2160117780 doi "https://doi.org/10.1029/gd028p0231" @default.
- W2160117780 hasPublicationYear "1998" @default.
- W2160117780 type Work @default.
- W2160117780 sameAs 2160117780 @default.
- W2160117780 citedByCount "157" @default.
- W2160117780 countsByYear W21601177802012 @default.
- W2160117780 countsByYear W21601177802013 @default.
- W2160117780 countsByYear W21601177802014 @default.
- W2160117780 countsByYear W21601177802015 @default.
- W2160117780 countsByYear W21601177802016 @default.
- W2160117780 countsByYear W21601177802017 @default.
- W2160117780 countsByYear W21601177802018 @default.
- W2160117780 countsByYear W21601177802019 @default.
- W2160117780 countsByYear W21601177802020 @default.
- W2160117780 countsByYear W21601177802021 @default.
- W2160117780 countsByYear W21601177802022 @default.
- W2160117780 countsByYear W21601177802023 @default.
- W2160117780 crossrefType "book-chapter" @default.
- W2160117780 hasAuthorship W2160117780A5060893488 @default.
- W2160117780 hasConcept C10899652 @default.
- W2160117780 hasConcept C111603439 @default.
- W2160117780 hasConcept C121332964 @default.
- W2160117780 hasConcept C127313418 @default.
- W2160117780 hasConcept C134018914 @default.
- W2160117780 hasConcept C165205528 @default.
- W2160117780 hasConcept C190799397 @default.
- W2160117780 hasConcept C2778024521 @default.
- W2160117780 hasConcept C2779306644 @default.
- W2160117780 hasConcept C57879066 @default.
- W2160117780 hasConcept C58097730 @default.
- W2160117780 hasConcept C67236022 @default.
- W2160117780 hasConcept C77928131 @default.
- W2160117780 hasConcept C8058405 @default.
- W2160117780 hasConcept C86803240 @default.
- W2160117780 hasConceptScore W2160117780C10899652 @default.
- W2160117780 hasConceptScore W2160117780C111603439 @default.