Mantle helium and other volatiles may be released to volcanic crater lakes. This paper presents the observation of H and mantle helium in the crater Lakes Nemrut (Turkey), Laacher (Germany) and Pavin (France). The presence of excess H in the lakes can be explained as material released from mantle sources because of the correlation of excess H with mantle He and He. The helium concentration was ...

We estimate terrestrial antineutrino and neutrino fluxes according to different models of Earth composition. We find large variations, corresponding to uncertainties on the estimated U , T h and K abundances in the mantle. Information on the mantle composition can be derived from antineutrino flux measurements after subtracting the crust contribution. This requires a good description of the cru...

Deciphering the origin of seismic velocity heterogeneities in the mantle is crucial to understanding internal structures and processes at work in the Earth. The spin crossover in iron in ferropericlase (Fp), the second most abundant phase in the lower mantle, introduces unfamiliar effects on seismic velocities. First-principles calculations indicate that anticorrelation between shear velocity (...

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 it...

We estimate terrestrial antineutrino and neutrino fluxes according to different models of Earth composition. We find large variations, corresponding to uncertainties on the estimated U , T h and K abundances in the mantle. Information on the mantle composition can be derived from antineutrino flux measurements after subtracting the crust contribution. This requires a good description of the cru...

Introduction: The last major event in Earth’s formation is thought to have been the collision with a Mars-sized differentiated impactor, resulting in the formation of the Earth-Moon system (EMS). The recent discussion of the timing of this event centers on the extent of equilibration of the Hf-W system during this event. While Hf-W equilibration was very effective in small planetesimals [1], it...

Nitrogen forms an integral part of the main building blocks of life, including DNA, RNA, and proteins. N2 is the dominant gas in Earth's atmosphere, and nitrogen is stored in all of Earth's geological reservoirs, including the crust, the mantle, and the core. As such, nitrogen geochemistry is fundamental to the evolution of planet Earth and the life it supports. Despite the importance of nitrog...

Introduction: Water is thought to be vital for the development of plate tectonics because it lowers viscosities in the asthenosphere and enables subduction. However, the following issue persists: if water is necessary for plate tectonics, but subduction itself hydrates the upper mantle, how is the upper mantle initially hydrated? Here we present models demonstrating that processes associated wi...

We perform a systematic study of the enhancement of the transitions ν µ (ν e) → ν e (ν µ;τ), ν 2 → ν e , ¯ ν µ → ¯ ν s , ν e → ν s , etc. of neutrinos passing through a medium of nonperiodic density distribution, consisting of i) two layers of different constant densities (e.g., Earth core and mantle), or ii) three layers of constant density with the first and the third layers having identical ...

The generation and evolution of Earth's continental crust has played a fundamental role in the development of the planet. Its formation modified the composition of the mantle, contributed to the establishment of the atmosphere, and led to the creation of ecological niches important for early life. Here we show that in the Archean, the formation and stabilization of continents also controlled th...