The high pressure phase transitions and melting of the mantle mineral MgSiO3 with the perovskite structure were investigated using molecular dynamics (MD) simulations of a large system of atoms on a parallel computer. The simulations reveal an orthorhombic to cubic transition accompanied by a sharp increase in diffusion of the O atoms. The phase transition and melting temperature depend sensiti...

BACKGROUND Type I insulin-like growth factor receptor (IGF-IR) tyrosine kinase induces significant oncogenic effects. Strategies to block IGF-IR signaling are being tested in clinical trials that include patients with aggressive solid malignancies. Mantle cell lymphoma is a B-cell neoplasm with poor prognosis and a tendency to develop resistance. The expression and potential significance of IGF...

New measurements of Os, He, Sr and Nd isotopes, along with major and trace elements, are presented for basalts from the three volcanic flank zones in Iceland and from Jan Mayen Island. The Os/Os ratios in lavas with <30 ppt Os (n = 4) are elevated compared to ratios in coexisting olivine and appear to be contaminated at a shallow level. The Os/Os ratios in the remaining lavas with >30 ppt Os (n...

The observed seismic anisotropy of the southern African mantle from both shear-wave splitting and surface wave observations provides important constraints on modes of mantle deformation beneath this ancient continent. We find that the mantle anisotropy beneath southern Africa is dominated by deformational events in Archean times occurring within the lithosphere, rather than present-day processe...

Processes within the lowest several hundred kilometers of Earth's rocky mantle play a critical role in the evolution of the planet. Understanding Earth's lower mantle requires putting recent seismic and mineral physics discoveries into a self-consistent, geodynamically feasible context. Two nearly antipodal large low-shear-velocity provinces in the deep mantle likely represent chemically distin...

Subducting lithospheric plates are the cool, downwelling limbs of mantle convection and the negative buoyancy of subducting slabs (slab pull) drives plate tectonics [Forsyth and Uyeda, 1975]. Subduction zones are regions of intense earthquake activity, explosive volcanism, and complex mass transfer between the crust, mantle, hydrosphere, and atmosphere. In this contribution, I present subductio...

Seismic data from central Tibet have been combined to image the subsurface structure and understand the evolution of the collision of India and Eurasia. The 410- and 660-kilometer mantle discontinuities are sharply defined, implying a lack of a subducting slab beneath the plateau. The discontinuities appear slightly deeper beneath northern Tibet, implying that the average temperature of the man...

[1] We study the contribution of mantle flow to surface deformation within the Mediterranean Basin. Flow is modeled numerically based on lateral changes in mantle temperature estimated from tomography models. We find that modeling results are significantly affected by the properties of the selected tomography models. Shear‐velocity models based on surface‐wave observations achieve the highest r...

Three-dimensional modeling of upper-mantle anelastic structure reveals that thermal upwellings associated with the two superplumes, imaged by seismic elastic tomography at the base of the mantle, persist through the upper-mantle transition zone and are deflected horizontally beneath the lithosphere. This explains the unique transverse shear wave isotropy in the central Pacific. We infer that th...