The origin of volcanism along the KurilKamchatka Island Arc (KKIA) was analyzed. Geophysical observations show variations in the slab parameters. Different widths of the volcanic belt in the northern and southern parts of the KKIA are caused by changes in the slab dip angle. The rift system of the Bussol Strait may be generated by significant changes in the slab velocity in the central segment of the KKIA. We proposed that the back-arc basin plays a predominant role in the formation of various parameters of the slab and manifestations of volcanism along the KKIA.
