Deep MT Sounding Across the Yellowstone-Snake River Hotspot Track

研究人员建议使用大地电磁（MT）探测来限制黄石-蛇河地区羽流物质的温度和熔融分数，并对黄石羽流及其与大陆相互作用的动力学模型提供限制。 先前的几项研究表明，在爱达荷州的斯内克河平原东部下方存在一个狭窄、低的P波速度，与黄石热点的运动方向一致。 较低的地震速度可以归因于温度差异，部分熔融，和熔融偏析造成的成分差异的综合影响。 调查人员建议沿沿着两条垂直线部署长周期MT测深仪器：第一条是西北至东南的断面，其P波速度模型先前通过层析反演获得，第二条以沿着蛇河平原为中心。 由于富含橄榄石的岩石的导电性强烈依赖于熔体分数和温度，MT测深数据的解释可以用来确定地幔温度和熔体分数，从而产生估计的地幔柱粘度。

EAR-0229814DeGroot-HedlinThe investigators propose to use magnetotelluric (MT) sounding to constrain the temperature and melt fraction of plume material in the Yellowstone-Snake River region, and provide constraints on models of the dynamics of the Yellowstone plume flow and its interaction with a continent. Several previous studies have indicated the presence of a narrow, low P-wave velocity beneath the eastern Snake River Plain in Idaho, aligned in the direction of motion of the Yellowstone hotspot. The lower seismic velocities can be attributed to the combined effects of temperature differences, partial melt, and compositional differences resulting from melt segregation. The investigators propose to deploy long period MT sounding instruments along two perpendicular lines: the first a northwest to southeast transect for which a P-wave velocity model was previously obtained from tomographic inversion, the second centered along the Snake River Plain. Given that the conductivity of olivine-rich rocks is strongly dependent upon both melt fraction and temperature, interpretation of MT sounding data can be used to determine mantle temperatures and melt fraction, hence yielding an estimate of plume viscosity.