Fig. 6: Vertical cross-sections through the vote maps.
From: Seismological expression of the iron spin crossover in ferropericlase in the Earth’s lower mantle
All four S-wave models (left) and four P-wave models (right) are used for profiles through (a) SE Asia and b the Farallon slab regions (vote maps for fast velocities), and (c) the African-Afar large low shear wave velocity province (LLSVP) and plume region (vote maps for slow velocities). Location maps are overlain with palaeo-subduction zones between 0 and 200 Ma as extracted from a global plate reconstruction77. Panels (a) and (b) identify vertically coherent fast regions that are common to S-wave models in the mid-mantle indicating the presence of subducted slabs whereas the slab signal is weak amongst P-wave models. This is more clear in the fast rather than (c) slow regions because at higher temperatures the HS-LS crossover shifts to greater depths where the seismic signal is dominated by the LLSVPs, and also occurs over a broader depth range.
