Temperature profiles in the Earth.
Abstract
A geotherm from 80 to 5153 km depth is proposed. The temperature gradient in the upper mantle is found by using laboratory data on minerals in conjunction with seismic traveltime curves. The temperature at the beginning of the transition zone, 380 km, is taken to be 1400 C, following the results of the phase transitions in olivine, according to Akaogi and Akimoto (1979). These data are also used to estimate the temperature gradient throughout the transition zone. The lower mantle temperature gradient is found by assuming adiabatic compresson and taking gamma to be gamma acoustic. A small correction is made for the effect of apparent superadiabaticity (100 C) throughout the lower mantle. The temperature gradient of the outer core is found by assuming adiabatic compression and by taking T to be constant (gamma = 1.4). An estimate for the DeltaT jump at thermal barriers at 670 km and 2885 km depth is needed. The result gives 4080 K at the innerouter core boundary. The results are compared with several current thermal models of the earth.
 Publication:

Evolution of the Earth
 Pub Date:
 1981
 Bibcode:
 1981evea.proc...19A
 Keywords:

 Earth Planetary Structure;
 Geotemperature;
 Temperature Profiles;
 Adiabatic Conditions;
 Earth Mantle;
 Olivine;
 Vertical Distribution;
 Geophysics;
 Earth Interior:Temperatures;
 Temperatures:Earth Interior