The velocity profile at the base of the liquid core from PKP(BC+Cdiff) data: An argument in favour of radial inhomogeneity
作者： Annie Souriau , Georges Poupinet
DOI: 10.1029/91GL02417
关键词: Stratification (water) 、 Geodesy 、 Inner core 、 Thermal 、 Liquid core 、 Physics 、 Velocity gradient 、 Homogeneity (physics) 、 Diffraction 、 Neutral density filter
摘要: The velocity profile at the base of core is derived from mean travel time PKP(BC+Cdiff) data collected by International Seismological Centre. PKP(BC) corresponds to rays having their turning points in lower third liquid core, which give great distance a branch Cdiff diffracted along inner boundary. Travel residuals are computed with respect Earth model PREM (Dziewonski and Anderson, 1981), whose nearly follows Adams-Williamson equation any depth, implying neutral density stratification. Positive values obtained for epicentral distances greater that 151°. They well explained constant lowermost 150 km. This strong decrease gradient favour stable stratification core. It cannot be thermal effects only but may correspond departure homogeneity, probably relation crystallization
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