  Multiscale interaction between the magnetic island and turbulence has been
demonstrated through simultaneous two-dimensional measurements of turbulence
and temperature and flow profiles. The magnetic island and turbulence mutually
interact via the coupling between the electron temperature ($T_e$) gradient,
the $T_e$ turbulence, and the poloidal flow. The $T_e$ gradient altered by the
magnetic island is peaked outside and flattened inside the island. The $T_e$
turbulence can appear in the increased $T_e$ gradient regions. The combined
effects of the $T_e$ gradient and the the poloidal flow shear determine
two-dimensional distribution of the $T_e$ turbulence. When the reversed
poloidal flow forms, it can maintain the steepest $T_e$ gradient and the
magnetic island acts more like a electron heat transport barrier.
Interestingly, when the $T_e$ gradient, the $T_e$ turbulence, and the flow
shear increase beyond critical levels, the magnetic island turns into a fast
electron heat transport channel, which directly leads to the minor disruption.
