Earth dons a different mantle
Article Abstract:
The earth's uppermost mantle contains peridotite which is a rock with 50-60% (Mg,Fe)2SiO4 olivine. Pressure variations in the transition zone induce transformation of olivine to spinel and perovskite-type crystal structures. These pressure-induced phase transitions of olivine increase the seismic wave velocities of the transition zone in the mantle at a depth of 410-660 kilo meters. There is disparity between the observed and the theoretically expected velocity jumps in the transition of olivine to beta spinel at a depth of 400 km.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1995
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Preparing for the worst
Article Abstract:
Scientists suggest that an international data bank of known nuclear explosive materials should be established in order to determine the source of nuclear materials following an explosion. The international database should include a database, a physical library of nuclear explosive materials and vetted procedures for handling both data and samples.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2006
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Taking the earth's temperature
Article Abstract:
Research on the use of seismic tomography to study variations in the earth's interior temperature is discussed. The mantle's temperature cannot be measured directly, but variations in temperature affect seismic wave speeds.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
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