In Earth's interior, what is the transition zone, in relation to the mantle?

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Offline calventeng

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Hi there...

I am someone who graduated from non-science major but addicted to science recently esp. in geological oceanography. There is a question that I can't find online and hope I can get some information here. For the upper mantle, there are lithosphere(L), asthenosphere(A), mesosphere(M) and trasition zone, with mantle thickness bout 1800miles.

Just wondering does transition zone is a zone between LAM and the lower mantle, or the LAM are part of the transition zone?

Thanks for the help!!
« Last Edit: 12/01/2010 16:38:12 by chris »


Offline chris

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Offline JimBob

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First, this question cannot really be understood as there is a significant lack of specificity.

This is a most difficult question to answer as there is are transition zones between each zone in the mantle. And there are differences within the earth's mantle zones. And there is also a transition zone at the outer core.

In general, viscosity increases with increasing depth (pressure.) But the increase in temperature also raises the viscosity. So the relationship of viscosity (or solidity) and depth is not linear. This causes a variable boundary between the outer and inner mantle. There are layers with dramatically less viscosity, both in the mantle and at the mantle - core boundary.

So I cannot say which of the transition zone is in question nor can I say that they are uniform around the earth - they are not.
The mind is like a parachute. It works best when open.  -- A. Einstein


Offline Bass

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Well stated JB!
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