9303884 Vanyo The PI will measure liquid motions in a filled oblate spheroid having the Earth's core-mantle boundary ellipticity during spin and precession scaled to the luni-solar induced precession of the mantle. Experimental techniques will trace interior (3-D) flows and surface secondary flows due to Ekman layer pumping. Instabilities and development of turbulence will be delineated. An equivalent diameter sphere will also be developed to approximate the observed flows, and the resulting data will be compared to buoyancy induced convection and to analytical geodynamo requirements. ****