Results are presented of a numerical investigation of the strongly non
linear bifurcation properties of an isothermal current sheet model whi
ch has previously been investigated in the weakly nonlinear regime by
analytical methods. With the method used, the linear stability of the
bifurcating branch is also checked. The results have applications in t
he stability of plasma systems with current sheets, e.g., the Earth's
magnetotail or solar coronal arcades.