The impact of variability in the rheological activation parameters on lower-mantle viscosity stratification and its dynamics

► We study the dynamical consequences of the reduction of the activation energy in the creep law. ► Our models are characterized by the series of the low viscosity channels located below 670 km interface, at the depth of about 1600 km and above the CMB. ► We observe tendency to the formation of small-scale convection below the 670 km interface and stable plumes or plume clusters in the lowermost mantle.