  Recent observations of the successive formations of the 4=1; 3=1, and 2=1
magnetic islands as well as the subsequent braking of the 2=1 mode during a
low-Z impurity penetration process in EAST experiments are well reproduced in
our 3D resistive MHD simulations. The enhanced parallel current perturbation
induced by impurity radiation predominately contributes to the tearing mode
growth, and the 2=1 island rotation is mainly damped by the impurity
accumulation as results of the influence from high n modes.
