The direction of the earth'smagneticpole, to which the north-seeking pole of a magnetic needle points when free from local magnetic influence.
地球磁极的方向，当不受当地磁场影响时，用来寻找北方磁极指示的方向。
2
If the Earth'smagneticpole reversal caused by biological extinction, it is not difficult to explain why from time to time, so that the periodic destruction of the Earth civilization.
假如地球磁极逆转而造成生物大量灭尽，那就不难表明为何每隔一段时间，使地球文明周期性的毁灭。
3
Earth is a very large magnetic field, the magnetic field lines from the North Pole, the Earth's surface into the South Pole.