  It is known that principal orbits of Hermann actions on a symmetric space of
non-compact type are curvature-adapted isoparametric submanifolds having no
focal point of non-Euclidean type on the ideal boundary of the ambient
symmetric space. In this paper, we investigate the mean curvature flows for
such a curvature-adapted isoparametric submanifold and its focal submanifold.
Concretely the investigation is performed by investigating the mean curvature
flows for the lift of the submanifold to an infinite dimensional pseudo-Hilbert
space through a pseudo-Riemannian submersion.
