Imaging the lowermost mantle (D″) and the core-mantle boundary withSKKScoda waves
نویسندگان
چکیده
منابع مشابه
Imaging the Lowermost Mantle ( D " ) Beneath the Pacific Ocean with SKKS Coda Waves
We apply a generalized Radon transform (GRT) to SKKS data to obtain a large-scale high-resolution image of the lowermost mantle (400 kilometers above the core-mantle boundary) beneath the Pacific Ocean (1250 E-750 W, 450 S-650 N in this work). More than 4,000,000 radial teleseismic traces from about 8,000 events (mb >= 5.8) between 1990 and 2015, globally recorded by one or more of a total ~27,...
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Torsional Alfvén waves propagating in the Earth’s core have been inferred by inversion techniques applied to geomagnetic models. They appear to propagate across the core but vanish at the equator, exchanging angular momentum between core and mantle. Assuming axial symmetry, we find that an electrically conducting layer at the bottom of the mantle can lead to total absorption of torsional waves ...
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The partial collapse of topographic structure at the core-mantle boundary (CMB) in avalanches, slumps or turbidity flows, would cause sudden temperature changes in both the upper core and the lower mantle. Although such collapses are hypothetical, it is interesting to investigate the potential consequences. Downwelling from such events could disrupt core convection cells and trigger geomagnetic...
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Extreme variations of Earth's magnetic field occurred in the Levant region around 1000 BC, when the field intensity rapidly rose and fell by a factor of 2. No coherent link currently exists between this intensity spike and the global field produced by the core geodynamo. Here we show that the Levantine spike must span >60° longitude at Earth's surface if it originates from the core-mantle bound...
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(1) Introduction.-In this paper, the values of variables at the base of the mantle and top of the core in the Earth models to be considered will be indicated by the subscripts 1 and 2, respectively; k and p will denote the incompressibility and density; let Ak = k2ki and Ap = p2 pi. In an earlier Earth model,1 Model A, k1 = 6.5 X 1012 dyn/cm2 and k2 = 6.2 X 1012 dyn/cm2, giving Ak = -0.3 X 1012...
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ژورنال
عنوان ژورنال: Geophysical Journal International
سال: 2008
ISSN: 0956-540X,1365-246X
DOI: 10.1111/j.1365-246x.2008.03861.x