Role of mantle plumes in the dynamics of the Earth mantle

As subducted slabs sink to the lowermost mantle, they push ahead both the hot thermal boundary layer above the core-mantle boundary and chemically heavy material that acculates in the lowermost mantle. The heavy material is piled up, and the hot material rises as plumes from the margins of the piles (Steinberger and Torsvik, 2012; Gaßmöller, 2015; Figure 1).Plumes entrain heavy material from the piles (Figure 2), which influences their behaviour (Mulyukova et al., 2015 and in preparation). The dynamics of this process – subduction of chemically dense material to the lowermost mantle, accumulation into piles and entrainment in plumes can be seen in the movie on this page created by Elvira Mulyukova.