学科：地球物理学 词目：变化磁场异常 英文：geomagnetic variation anomaly 释文：某观测站的变化磁场相对于参考站出现差分变化的数值用参考站约化后，一般大于0.15，即可认为出现变化磁场异常。
本文使用地磁短周期转换函数和提取地磁局部异常的方法，对菏泽5.9级地震前后地磁场的变化进行了再研究。
Using the short-period conversion function and extracting local anomaly from the geomagnetic field, we have re-studied the variation of the geomagnetic field before and after the Heze 5.9 earthquake.
对全部测点观测资料的分析后发现，全测区磁场的异常变化较小。
In analysing the data thus obtained, it is found that anomalous variations of the geomagnetic total field within the entire area are relatively slight.
从全球磁场减去地核主磁场和变化磁场及其感应磁场后，就得到岩石圈磁场，又称地壳磁场，或地磁异常。
The crust magnetic field, or lithospheric magnetic field, can be deduced by subtracting the main field, variation field and its induced counterpart from the total field.
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