ELASTIC BOUNDARY-CONDITIONS IN LONG-PERIOD CORE OSCILLATIONS

The Earth's core is a contained rotating fluid. In contrast to the classical theory of rotating, incompressible fluids in rigid containers, a realistic treatment of the geophysical problem requires allowance for the compressibility of the fluid core, and for the elasticity of the shell (mantle and crust) and inner core. It is shown in this paper that when these realistic properties are included in the model, the governing sub‐seismic wave equation and boundary conditions are fully Hermitean and a general functional governing the problem can be constructed. Compressibility is treated through a decompression factor which multiplies the displacement field to generate a new, solenoidal, displacement vector field, while elasticity of the boundaries is incorporated by means of internal load Love numbers. Both the decompression factor for the fluid core and the internal load Love numbers for the shell and inner core are computed for realistic Earth models. Copyright © 1990, Wiley Blackwell. All rights reserved