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

为了探索最近发现的位于地幔底部的超低速度带（ULVZ）的化学、结构和热性质，研究人员建议将核-地幔边界结构的地震调查与统计分析、矿物物理实验（在超高压下的熔融/固体共存）以及远离CMB的热平流和传导速率模拟结合起来。该带可能包含部分熔融物，结构复杂，化学成分可能与上覆地幔不同。这个区域的上升流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绕射波的波形建模来表征超视场的厚度和位置；(2)对现有地震观测资料进行统计分析，表征超低震区的空间变异性；(3)利用流体动力学模拟来约束可能的对流和传导热流分量，包括穿过ULVZ和非ULVZ区域；(4)确定超高压条件下天然橄榄岩组合中液相相的组成。

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.