Neutrino tomography of Earth's mantle

Neutrino geophysics is an interdisciplinary field with the potential to map the abundances and distribution of radiogenic heat sources in the continental crust and deep Earth. To date, data from two different experiments quantify the amount of Th and U in the Earth, and begin to put constraints on radiogenic power in the Earth available for driving mantle convection and plate tectonics. New improved detectors are under construction or in planning stages. Critical testing of compositional models of the Earth requires integrating geoneutrino and geological observations. Such tests will lead to significant constraints on the absolute and relative abundances of Th and U in the continents. High radioactivity in continental crust puts limits on land-based observatories' capacity to resolve mantle models with current detection methods. However, the quantification of deep-seated radioactivity is crucial for understanding the composition and dynamics of the Earth, including its thermal evolution, the style and planform of mantle convection, and the energetics of the core. Estimates of mantle radiogenic heat production vary significantly between some models. Some models require a mantle reservoir enriched in heat producing elements relative to the source of mid-oceanic ridge basalts. Such a reservoir is likely to show strong variation in thickness in the convecting mantle; it is usually identified with the seismically seen low shear wave velocity provinces (LLSVPs) in the deep mantle. The resulting laterally variable geoneutrino signal at Earth's surface may be measurable, thus offering an unprecedented direct detection of deep mantle chemical variability. I will review the recent advances in geoneutrino research with a particular focus on mantle geoneutrino detection.