TY  - JOUR
AV  - public
SP  - 1349
VL  - 350
Y1  - 2015/12/11/
EP  - 1352
TI  - Viscosity jump in Earth's mid-mantle
IS  - 6266
N1  - This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science {350, 11 December 2015}, doi: 10.1126/science.aad1929.
UR  - http://dx.doi.org/10.1126/science.aad1929
SN  - 1095-9203
N2  - The viscosity structure of Earth's deep mantle affects the thermal evolution of Earth, the ascent of mantle plumes, settling of subducted oceanic lithosphere, and the mixing of compositional heterogeneities in the mantle. Based on a reanalysis of the long-wavelength nonhydrostatic geoid, we infer viscous layering of the mantle using a method that allows us to avoid a priori assumptions about its variation with depth. We detect an increase in viscosity at 800- to 1200-kilometers depth, far greater than the depth of the mineral phase transformations that define the mantle transition zone. The viscosity increase is coincident in depth with regions where seismic tomography has imaged slab stagnation, plume deflection, and changes in large-scale structure and offers a simple explanation of these phenomena.
ID  - discovery1477315
A1  - Rudolph, ML
A1  - Leki?, V
A1  - Lithgow-Bertelloni, C
JF  - Science
ER  -