据 Nature.1997.389:712报道,美国和法国的科学家对最近两次的地磁极性反向进行了研究。到现在为止,地球磁场方向已经翻转了几百次,而有记录的最近两次反向(布容期和松山期的反向)发生在7.8万年前。一般认为,发生反向的持续时间为1000～6000年,且地球表面磁场的平均强度据估计会降至原来的 According to Nature. 1997.389: 712, U.S. and French scientists have conducted a study of the last two geomagnetic reversals. Until now, the direction of the earth's magnetic field has flipped hundreds of times, and the most recent recorded reversal (the reversal of the Burson and Matsuyama periods) occurred 78,000 years ago. It is generally accepted that the reverse occurs for a duration of 1000-6000 years and that the average intensity of the Earth's surface magnetic field is estimated to be reduced to the original