CSEDI Collaborative Research: Multidisciplinary Studies of the Core-Mantle Boundary Region

9905733威廉姆斯研究人员建议将核幔边界结构的地震探测与统计分析、矿物物理实验（关于超高压下的熔体/固体共存），并模拟远离CMB的热平流和传导速率，以探索化学，最近在地幔底部发现的超低速带（ULVZ）的结构和热性质。 这个区域可能包含部分熔融，结构复杂，化学成分可能与上覆地幔不同。 这个地带的隆起也可能在地球表面产生热点。研究人员计划（1）利用宽带地震数据和CMB衍射波的波形建模来表征ULVZ的厚度和位置;（2）统计分析现有的地震观测结果来表征ULVZ的空间变化;（3）使用流体动力学模拟来限制穿过ULVZ和非ULVZ区域的热流的可能平流和传导成分;（4）测定超高压下天然橄榄岩组合的液相组成。

9905733 Williams The investigators propose to couple seismic interrogations of the structure of the core-mantle boundary with statistical analyses, mineral physics experiments (on melt/solid coexistence at ultra-high pressure), and simulations of rates of heat advection and conduction away from the CMB in order to explore the chemical, structural and thermal properties of the recently discovered ultra-low velocity zone (ULVZ) at the base of Earth's mantle. This zone likely contains partial melt, is structurally complex and may be chemically distinct from the overlying mantle. Upwellings from this zone also probably produce hot spots at Earth's surface. The investigators plan to (1) utilize broad band seismic data and waveform modeling of diffracted waves at the CMB to characterize the thicknesses and locations of ULVZ's; (2) statistically analyze available seismic observations to characterize the spatial variability of the ULVZ; (3) constrain likely advective and conductive components of heat flow across both the ULVZ and non-ULVZ-containing regions using fluid dynamic simulations; and (4) determine the compositions of liquidus phases in natural peridotitic assemblages at ultra-high pressures.