Podrobnosti záznamu

Název
    Are mantle plumes adiabatic?
Údaj o odpovědnosti
    Ctirad Matyska, David A. Yuen
Autor
    Matyska, Ctirad
    Yuen, David A.
Jazyk
    anglicky
Zdrojový dokument - seriál
    Earth and planetary science letters
Svazek/č.
    Vol. 189, no. 3-4
Strany
    p. 165-176
Rok
    2001
Poznámky
    6 obr., 34 bibl.
    il.
    Zkr. název ser.: Earth planet. Sci. Lett.
Předmětová skupina
    gradient geotermický
    model matematický
    plášť
    plášťový chochol
    proces adiabatický
    proudění konvekční
    vodivost tepelná
Klíčové slovo
    Adiabatic
    Mantle
    Plumes
Abstrakt (anglicky)
   The issue concerning the state of adiabaticity of mantle plumes has been examined in a cartesian two-diensional box with an aspect-ratio of six. We have investigated in the quasi steady-state regime high Rayleigh number convection with both depth-dependend viscosity and thermal expansivity for both the Boussinesq and the extended Boussinesq approximations. We have also assessed the influence of various forms of thermal conductivity and internal heating. We have generalized the classical Bullen's parameter equation from one dimension to multidimensions. For assessing the local state of adiabaticity inside plumes and in their surroundings, we have extracted from the local geoterms and the local thermodynamic properties the corresponding Bullen's parameter profiles and the two-dimensional maps portraying the state of adiabaticity in the mantle. Histograms characterizing the frequency of adiabaticity are also employed for quantification purposes.
   In general, superadiabatic thermal gradients are found inside the thick plume limbs and sometimes along the central part of the plume. The centres of plume heads are subadiabatic or nearly adiabatic, but the edges of the plume heads are strongly subadiabatic. Alternating strips of subadiabaticity and adibaticity are found in the downwellings. The ambient mantle outside the plumes is generally adiabatic and is sometimes perforated with islands of marked deviations from adiabaticity
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    21. 8. 2007
Datum importu
    8. 8. 2012