@article{MulyukovaSteinbergerDabrowskietal.2015,
  author    = {Mulyukova, Elvira and Steinberger, Bernhard and Dabrowski, Marcin and Sobolev, Stephan Vladimir},
  title     = {Survival of LLSVPs for billions of years in a vigorously convecting mantle: Replenishment and destruction of chemical anomaly},
  series = {Journal of geophysical research : Solid earth},
  volume    = {120},
  journal   = {Journal of geophysical research : Solid earth},
  number    = {5},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {2169-9313},
  doi       = {10.1002/2014JB011688},
  pages     = {3824 -- 3847},
  year      = {2015},
  abstract  = {We study segregation of the subducted oceanic crust (OC) at the core-mantle boundary and its ability to accumulate and form large thermochemical piles (such as the seismically observed Large Low Shear Velocity Provinces (LLSVPs)). Our high-resolution numerical simulations of thermochemical mantle convection suggest that the longevity of LLSVPs for up to three billion years, and possibly longer, can be ensured by a balance in the rate of segregation of high-density OC material to the core-mantle boundary (CMB) and the rate of its entrainment away from the CMB by mantle upwellings. For a range of parameters tested in this study, a large-scale compositional anomaly forms at the CMB, similar in shape and size to the LLSVPs. Neutrally buoyant thermochemical piles formed by mechanical stirringwhere thermally induced negative density anomaly is balanced by the presence of a fraction of dense anomalous materialbest resemble the geometry of LLSVPs. Such neutrally buoyant piles tend to emerge and survive for at least 3Gyr in simulations with quite different parameters. We conclude that for a plausible range of values of density anomaly of OC material in the lower mantleit is likely that it segregates to the CMB, gets mechanically mixed with the ambient material, and forms neutrally buoyant large-scale compositional anomalies similar in shape to the LLSVPs.},
  language  = {en}
}
@article{GeryaSternBaesetal.2015,
  author    = {Gerya, Taras V. and Stern, Robert J. and Baes, Marzieh and Sobolev, Stephan Vladimir and Whattam, Scott A.},
  title     = {Plate tectonics on the Earth triggered by plume-induced subduction initiation},
  series = {Nature : the international weekly journal of science},
  volume    = {527},
  journal   = {Nature : the international weekly journal of science},
  number    = {7577},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {0028-0836},
  doi       = {10.1038/nature15752},
  pages     = {221 -- +},
  year      = {2015},
  abstract  = {Scientific theories of how subduction and plate tectonics began on Earth-and what the tectonic structure of Earth was before this-remain enigmatic and contentious(1). Understanding viable scenarios for the onset of subduction and plate tectonics(2,3) is hampered by the fact that subduction initiation processes must have been markedly different before the onset of global plate tectonics because most present-day subduction initiation mechanisms require acting plate forces and existing zones of lithospheric weakness, which are both consequences of plate tectonics(4). However, plume-induced subduction initiation(5-9) could have started the first subduction zone without the help of plate tectonics. Here, we test this mechanism using high-resolution three-dimensional numerical thermomechanical modelling. We demonstrate that three key physical factors combine to trigger self-sustained subduction: (1) a strong, negatively buoyant oceanic lithosphere; (2) focused magmatic weakening and thinning of lithosphere above the plume; and (3) lubrication of the slab interface by hydrated crust. We also show that plume-induced subduction could only have been feasible in the hotter early Earth for old oceanic plates. In contrast, younger plates favoured episodic lithospheric drips rather than self-sustained subduction and global plate tectonics.},
  language  = {en}
}
@article{DannbergSobolev2015,
  author    = {Dannberg, Juliane and Sobolev, Stephan Vladimir},
  title     = {Low-buoyancy thermochemical plumes resolve controversy of classical mantle plume concept},
  series = {Nature Communications},
  volume    = {6},
  journal   = {Nature Communications},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {2041-1723},
  doi       = {10.1038/ncomms7960},
  pages     = {9},
  year      = {2015},
  abstract  = {The Earth's biggest magmatic events are believed to originate from massive melting when hot mantle plumes rising from the lowermost mantle reach the base of the lithosphere. Classical models predict large plume heads that cause kilometre-scale surface uplift, and narrow (100 km radius) plume tails that remain in the mantle after the plume head spreads below the lithosphere. However, in many cases, such uplifts and narrow plume tails are not observed. Here using numerical models, we show that the issue can be resolved if major mantle plumes contain up to 15-20\% of recycled oceanic crust in a form of dense eclogite, which drastically decreases their buoyancy and makes it depth dependent. We demonstrate that, despite their low buoyancy, large enough thermochemical plumes can rise through the whole mantle causing only negligible surface uplift. Their tails are bulky (4200 km radius) and remain in the upper mantle for 100 millions of years.},
  language  = {en}
}