Temperature gradients in a low-shear-velocity province in the lowermost mantle (D'' region) beneath the central Pacific Ocean were inferred from the observation of a rapid S-wave velocity increase overlying a rapid decrease. These paired seismic discontinuities are attributed to a phase change from perovskite to post-perovskite and then back to perovskite as the temperature increases with depth...

On Earth, the velocity at which subducting plates are consumed their trenches (termed “subduction rate” herein) is typically 3 times higher than trench migration velocities. The subduction rate also 5 estimated lower mantle slab sinking rates. Using simple kinematic analyses, we show that if this present-day “kinematic state” operated into past, lithosphere should have accumulated and folded be...

The discovery of a phase transition in Mg-rich perovskite (Pv) to a post-perovskite (pPv) phase at lower mantle depths and its relationship to D′′, lower mantle heterogeneity and iron content prompted an investigation of the relative importance of lower mantle compositional and temperature fluctuations in creating topographic undulations on mixed phase regions. Above the transition, Mgrich Pv m...

The statistical correlation between the locations of hot spots at the surface of Earth and the distribution of ultra-low-velocity zones at the base of the mantle has about a 1 percent chance of arising randomly. This correlation is more significant than that between hot spots and negative velocity anomalies in tomographic models of deep mantle compressional and shear velocity. This correlation ...

Free surface modeling plays an important role in some ocean structures design, especially in Oscillating Water Column (OWC) devices. Boundary element method (BEM) is a suitable method for free surface modeling due to its simplicity, quick solving, and low data storage requirement. In this paper, BEM was used for free surface modeling in OWC chamber and out of it. Linear kinematic and dynamic bo...

[1] The mantle plume hypothesis provides explanations for several major observations of surface volcanism. The dynamics of plumes with purely thermal origin has been well established, but our understanding of the role of compositional variations in the Earth’s mantle on plume formation is still incomplete. In this study we explore the structures of plumes originating from a thermochemical bound...