Interaction of mantle dregs with convection: Lateral heterogeneity at the core‐mantle boundary
作者:
Geoffrey F. Davies,
Michael Gurnis,
期刊:
Geophysical Research Letters
(WILEY Available online 1986)
卷期:
Volume 13,
issue 13
页码: 1517-1520
ISSN:0094-8276
年代: 1986
DOI:10.1029/GL013i013p01517
数据来源: WILEY
摘要:
Preliminary numerical models indicate that chemically denser material (dregs) at the base of the mantle would have substantial lateral variations in thickness induced by convection of the overlying mantle, and might well form discontinuous aggregations below mantle upwellings. A model with a density contrast of about 2 per cent and an initial uniform thickness of the denser layer of 100 km yields a discontinuous distribution with maximum thickness 230 km and bottom topography of several kilometers amplitude, in reasonable accord with recent seismological observations of vertical and lateral structure. Heat flux out of the core is probably strongly modulated laterally by mantle convection, while mantle dregs will complicate and possibly amplify this effect. Such modulation may be relevant to long‐term (107‐ 108year) variations in the magnetic fi
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