Mantle tomography and its relation to temperature and composition

TL;DR: In this article , the authors show that weak and moderate post-perovskite phase transition in the lowermost mantle can facilitate or prevent the accumulation of basaltic oceanic crust at the base of the mantle.

TL;DR: In this article , the authors carried out a statistical analysis (Linear Discriminant Analysis) finding that there is a marked difference in mantle mineralogy to explain R values larger and smaller than 3.

TL;DR: In this paper, the aggregate shear wave velocities of MgO (periclase) have been determined throughout Earth's lower mantle pressure regime approaching 130 GPa using Brillouin spectroscopy in conjunction with synchrotron X-ray diffraction technique in a diamond anvil cell apparatus.

TL;DR: Deschamps et al. as discussed by the authors explored the model space of thermo-chemical convection and found significant differences in the flow pattern and efficiency of mixing with probabilistic tomography.

TL;DR: In this article, a new empirical traveltime curves for the major seismic phases have been derived from the catalogues of the International Seismological Centre by relocating events by using P readings, depth phases and the iasp91 traveltimes, and then re-associating phase picks.

TL;DR: A boundary between compositionally distinct regions at a depth of about 1600 kilometers may explain the seismological observations pertaining to Earth's lower mantle, produce the isotopic signatures of mid-ocean ridge basalts and oceanic island basalts, and reconcile the discrepancy between the observed heat flux and the heat production of the mid-Ocean ridge basalt source region.

TL;DR: In this article, the relative amplitudes of compressional and shear velocity anomalies in the lower mantle are investigated and some robust patterns are beginning to emerge which allow us to identify regions of the lower lower mantle which are anomalous.

TL;DR: The presence of an intermittent layer at the base of Earth9s mantle with a maximum thickness near 40 kilometers and a compressional wave velocity depressed by ∼10 percent compared with that of the overlying mantle is most simply explained as the result of partial melt at this depth.