  We establish criteria for turbulence in certain spaces of C*-algebra
representations and apply this to the problem of nonclassifiability by
countable structures for group actions on a standard atomless probability space
(X,\mu) and on the hyperfinite II_1 factor R. We also prove that the conjugacy
action on the space of free actions of a countably infinite amenable group on R
is turbulent, and that the conjugacy action on the space of ergodic
measure-preserving flows on (X,\mu) is generically turbulent.
