  We report the observation of wave turbulence on the surface of a ferrofluid
mechanically forced and submitted to a static normal magnetic field. We show
that magnetic surface waves arise only above a critical field. The power
spectrum of their amplitudes displays a frequency-power law leading to the
observation of a magnetic wave turbulence regime which is experimentally shown
to involve a 4-wave interaction process. The existence of the regimes of
gravity, magnetic and capillary wave turbulence is reported in the phase space
parameters as well as a triple point of coexistence of these three regimes.
Most of these features are understood using dimensional analysis or the
dispersion relation of the ferrohydrodynamics surface waves.
