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News Science

Geologists Claim Earth May Be Softer Around The Middle Than Previously Thought 98

A new geological study is suggesting that what we know about the lower mantle of the Earth may have to be reevaluated. Since we are unable to actually sample the Earth at those depths, scientists rely on the use of seismic waves to study the lower reaches of the Earth. This new study suggests that material in the lower mantle has unusual characteristics that make sound move more slowly, suggesting a softer makeup than previously thought. "What's most important for seismology is the acoustic properties--the propagation of sound. We determined the elasticity of ferropericlase through the pressure-induced high-spin to low-spin transition. We did this by measuring the velocity of acoustic waves propagating in different directions in a single crystal of the material and found that over an extended pressure range (from about 395,000 to 590,000 atmospheres) the material became 'softer'--that is, the waves slowed down more than expected from previous work. Thus, at high temperature corresponding distributions will become very broad, which will result in a wide range of depth having subtly anomalous properties that perhaps extend through most of the lower mantle."
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Geologists Claim Earth May Be Softer Around The Middle Than Previously Thought

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  • by Knuckles ( 8964 ) <knuckles@@@dantian...org> on Monday January 28, 2008 @02:22PM (#22210358)
    I didn't know that creationists think that planet earth developed through evolution. This might explain some of their confusion, then.
    As for the quote from Genesis: you might be better off reading a version that was not mangled by hundreds of years of wrong translations and political machinations.
  • by Anonymous Coward on Monday January 28, 2008 @05:44PM (#22213532)
    So, scientists don't know as much about the Earth as they thought they did. What does this mean about global warming? Maybe we should think long and hard about making political decisions based on information that may be incomplete, not fully understood and possibly incorrect.

An authority is a person who can tell you more about something than you really care to know.

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