Internal structure of the Earth inferred from free oscillations

摘要: A new set of weighted means observed periods free oscillations are used to estimate an earth model by least-squares inversion. All modes considered, but only the fundamentals plus 1S0 and 2S0 explicitly in The method uses partial derivatives period with respect P velocity, S density. Derivatives size core affect low-order spheroidal as much 0.8 sec/km change. is developed two stages. First, geophysical arguments that generally independent inferences from develop approximate model, HT11GS1. Secondly, inversion derive it a DI-11, which fits overall rms deviation 0.61 second. DI-11 characterized rapid increase density at depths 500 800km, Adams-Williamson below 1100km, jump 2 g/cm3 base outer core, shear velocity 2.18 km/sec inner core. existence solid gets some support observations oscillations.