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近期发现地球内核地震波速度的各向异性对称轴有10°的倾斜,由此确定了内核相对于地幔的方位随时间的变化。以国际地震中心(ISC)1964～1992年29年的资料为基础,两种分析射线穿过内核时走时变化的方法都揭示:内核的旋转每年比地幔快3°。1969～1973年内核方位的异常变化在时间上与地磁场的突变一致。
Recently, it has been found that the anisotropy axis of symmetry of seismic velocity of the Earth’s core is inclined by 10 °, and thus the orientation of the core with respect to the mantle is determined over time. Based on the information of the International Seismological Center (ISC) from 1964 to 1992 for 29 years, two methods for analyzing the traveltimes of rays as they pass through the kernel reveal that the rotation of the kernel is 3 ° faster than the mantle every year. The anomalous change in the orientation of the core from 1969 to 1973 coincided with the sudden change of the geomagnetic field in time.