ULVZs, which are located in the lower mantle near the core-mantle ... Some of these so-called PKP waves travel through the mantle, the liquid outer core, and then the mantle again on their way ...

Above the inner core is the outer core, a shell of liquid iron. This layer is cooler ... to be divided into two layers: the upper mantle and the lower mantle. The boundary between the two lies ...

According to the study “Dehydration Melting at the Top of the Lower Mantle” (2014), this discovery suggests a “whole-Earth water cycle,” with water moving not only between surface and ...