Probing the Earth's Core

小行星9506708 这项研究是为了模拟地震波穿过地球核心的记录，以恢复其详细的结构。 在早期的工作中，内核被证实是各向异性的，具有围绕地球自转轴的圆柱对称性，其中N-S方向的P波速度比E-W方向快3%。 内核的最顶部60 km似乎不是各向异性的，从60到150 km的间隔是一个过渡区。 几个问题仍然存在，包括各向异性的细节和各向同性区域附近的内核边界的性质。 理论上可能的，但未被检测到的，相位PKJKP将再次寻求在光的各向异性的新信息。 这些问题的答案与地球磁场的性质、地核物质的组成和物理性质有关。 ***

9506708 SONG This research is to model recordings of seismic waves travelling through the earth's core to recover its detailed structure. The inner core, from earlier work, is confirmed to be anisotropic, possessing a cylindrical symmetry around the earth spin axis with the N-S direction 3% faster in P-wave velocity than the E-W direction. The very top 60 km of the inner core appears not to be anisotropic with the interval from 60 to 150 km being a transition region. Several questions remain including the details of the anisotropy and the nature of the isotropic region near the inner core boundary. The theoretically possible, but undetected, phase PKJKP will be sought again in light of the new information on anisotropy. The answer to these questions bear on the nature of the earth's magnetic field, and the composition and physics of the core's material. ***