Geophysical observations provide a variety of constraints upon the composition of the Earth's mantle. Here we review those constraints. We summarize a number of geophysical methods, both seismological and electromagnetic. Structure (in density, seismic wave speeds, and electrical resistivity) ascertained through these methods, when combined with laboratory measurements of mineralogical phase relations, illuminate trade-offs between compositional and thermal variability. These methods also serve to highlight regimes of compositional heterogeneity, including those associated with subducting slabs, transport of volatiles, mantle plumes, and deep mantle scatterers of seismic energy. Finally, we focus upon the various complexities apparent in the lowermost mantle just above the core-mantle boundary.
|Original language||English (US)|
|Title of host publication||The Mantle and Core|
|Number of pages||25|
|State||Published - Nov 2013|
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Environmental Science(all)