Seismic detection of post-perovskite inside the Earth

Since 2004, we have known that perovskite, the most abundant mineral in the lower mantle, has the capacity to transform to a denser structure, postperovskite, if subjected to sufficiently high temperature and pressure. But does post-perovskite exist inside the Earth? And if it does, do we have the resources to locate it seismically? In this chapter, we present an overview of what we know about the perovskite-to-post-perovskite phase transformation from mineral physics, and how this can be translated into seismic structure. In light of these constraints, we evaluate the current lines of evidence from global and regional seismology which have been used to indicate that post-perovskite is likely present in the deep mantle.