  In this paper we characterize the mixing properties in the advection of
passive tracers by exploiting the extreme value theory for dynamical systems.
With respect to classical techniques directly related to the Poincar\'e
recurrences analysis, our method provides reliable estimations of the
characteristic mixing times and distinguishes between barriers and unstable
fixed points. The method is based on a check of convergence for extreme value
laws on finite datasets. We define the mixing times in terms of the shortest
time intervals such that extremes converge to the asymptotic (known) parameters
of the Generalized Extreme Value distribution. Our technique is suitable for
applications in the analysis of other systems where mixing time scales need to
be determined and limited datasets are available.
