High Resolution Studies of Deep Earth Conductivity

迄今为止，PI的工作有力地表明，人们可以以前所未有的分辨率看到地球上部1000公里的导电性结构。已经分析的数据需要在400公里和650公里的地震不连续面附近有两次急剧的跳跃。如果这个结果是正确的，那么它应该为地幔的组成和物理状态提供一个强有力的约束。PI采用了鲁棒处理，消除了各种噪声，包括近表面横向非均匀性引起的电场畸变的影响。这种处理产生的大地电磁阻抗比以前得到的要精确得多。该数据已经使用一种算法进行了反转，该算法产生全局最平坦的模型，在其误差范围内拟合数据。这个最小结构模型需要局部跳跃的事实有力地证明了它们的真实性。PI将非常仔细地检查该处理的每一步，以提高计算的效率和鲁棒性。这项工作将包括审查其他现成的数据。

The PI's work to date strongly suggest that one can see conductivity structure in the upper 1000km of the Earth with unprecedented resolution. The data already analyzed requires two sharp jumps near the 400 and 650km seismic discontinuities. If this result is true, it should provide a powerful constraint on the compositon and physical state of the mantle. The PI has used robust processing which removes a variety of noises, including the effects of distortion of the electric field by near surface lateral heterogeneities. This processing produces magnetotelluric (MT) impedances which are much more accurate than previously obtained. This data has been inverted using an algorithm that produces the globally flattest model fitting the data within its errors. The fact that this least structure model requires localized jumps argues strongly for their reality. The PI will very carefully examine each step of this processing to improve both the efficiency and robustness of the compu- tations. This effort will include examining other readily available data.