  This work is devoted to analysis of the nonlinear dynamics of interrelated
thermal and electromagnetic perturbations in a superconductor caused by
dissipative effects involved in the viscous motion of the magnetic flux. The
structure and evolution of the stationary thermomagnetic waves propagating in
the superconductor is studied based on a system of nonlinear equations
describing dynamics of the instability development in the system studied. The
apperance of these structures is qualititively described and the wave
propagation velocity is estimated. The affect a thermoactivated flux creep to
the structures of the nonlinear thermomagnetic wave propagation is studied. It
is shown that taking into account a nonlinear dependency of the current density
$j$ on the electric field strength $E$ would not qualitatively change the main
results, since the character of the equilibrium state on the phase plane
remains esentially the same.
