Re: how do we know the temperature of the asthenosphere ?

Date: Thu Jan 30 09:55:12 2003
Posted By: Eder Molina, Researcher PhD, Dept. of Geophysics, Institute of Astronomy and Geophysics - USP
Area of science: Earth Sciences
ID: 1042133481.Es

Message:

Seismic waves have a great contribution on determining the temperature of the lithosphere, and, consequently, the temperature of the upper asthenosphere. The main point here is that the wave velocities depend upon several parameters, and one of the most important is the temperature. So, by modelling the wave velocities vertical distribution, one can model the lithosphere thermal structure. The process is not so simple, and it requires also a thermal conductivity model to calculate the lithosphere distribution of temperature, and some assumption on the distribution of heat producing elements in this region in order to constrain some parameters.
A recent work on the determination of the thermal structure of the lithosphere (and so, the top of the asthenosphere) was presented by Irina Artemieva and Walter D. Mooney, and you can see the poster in the attached images. The references below can help you in the understanding of this process.

Best regards

Eder C. Molina (eder@iag.usp.br)
Dept. of Geophysics
Institute of Astronomy, Geophysics and Atmospheric Sciences
University of Sao Paulo - BRAZIL

REFERENCES

Artemieva, I.M. & Mooney, W.D., 2001. Thermal structure and evolution of Precambrian Lithosphere. Journal of Geophysical Research, 106, 16387-16414.

Pollack, H.N., Hurter, S.J. and Johnson, J.R., 1993. Heat flow from the Earth's interior: analysis of the geothermal data set. Reviews of Geophysics, 31, 267-280.