  It has been proposed recently by Loureiro & Boldyrev [Phys. Rev. Lett. 118,
245101 (2017)] and Mallet et al. [Mon. Not. R. Astron. Soc. 468, 4862 (2017)]
that strongly anisotropic current sheets formed in the inertial range of
magnetohydrodynamic turbulence become affected by the tearing instability at
scales smaller than a critical scale $\lambda_\mathrm{c}$, and larger than the
dissipation scale of turbulence. If true, this process can modify the nature of
energy cascade at smaller scales, leading to a new, tearing-mediated regime of
magnetohydrodynamic (MHD) turbulence. In this work we present a numerical study
of strongly anisotropic, two-dimensional turbulent eddies, and we demonstrate
that the tearing instability can indeed compete with their nonlinear evolution.
The results, therefore, provide direct numerical support for the picture that a
new regime of MHD turbulence can exist below $\lambda_\mathrm{c}$.
