Earth’s Upper Mantle: How Low Can It Flow?
AUG 01, 1997
Does material in Earth’s mantle circulate within the upper and lower regions separately, never mixing, or is the entire mantle stirred as one? The latest evidence indicates that convection involves at least some deep mixing of the upper mantle.
DOI: 10.1063/1.881853
For years, a debate has raged among Earth scientists about the convection within our planet’s thick mantle. Most researchers agree that the 3000 km thick mantle is divided into an upper region and a lower region by an interface at a depth of about 660 km where the mantle materials undergo an isochemical phase change. But they differ as to whether this seismic discontinuity is a barrier to convection.
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© 1997 American Institute of Physics
