3D Numerical Modelling of Plume-Lithosphere Interaction

PI将对地幔柱移动岩石圈板块的热-力学相互作用进行真实三维几何的数值研究。该模型由一个矩形盒子组成，盒子内装有变粘度流体。岩石圈表现为盒子顶部以0速度运动的高粘性流体，而地幔柱是通过在盒子底部施加高斯形状的温度异常而产生的。流动的数值解将使用Christensen和Harder（1991）的混合谱-有限差分法得到。然后，这些解决方案将用于计算地形、大地水准面和热流异常、熔体产生速率以及喷发熔体的化学和同位素组成。通过将这些参数与来自不同热点的观测结果进行比较，模型将受到限制，特别要注意夏威夷。问题包括中间板块膨胀的起源（热支撑与动力支撑），岩石圈减薄的有效性，以及夏威夷火山活动四阶段演化模式的起源。

The PI will carry out a numerical study in realistic 3D geometry of the thermomechanical interaction of mantle plumes moving lithospheric plates. The model consists of a rectangular box containing fluid with variable viscosity. he lithosphere is represented by highly viscous fluid at the top of the box that moves with velocity Uo, and the plume is generated by imposing a Gaussian-shaped temperature anomaly on the bottom of the box. Numerical solutions for the flow will be obtained using the hybrid spectral-finite difference method of Christensen and Harder (1991). The solutions will then be used to calculate topography, geoid, and heat flow anomalies, melt production rates, and the chemical and isotopic composition of erupted melts. The models will be constrained by comparing these parameters with observations from various hotspots, with special attention to Hawaii. Questions include the origin of midplate swells (thermal vs. dynamical support), the effectiveness of lithospheric thinning, and the origin of the four-stage evolutionary pattern of Hawaiian volcanism.