摘要
地球磁场多次发生南北(正负)磁极位置的变换,即极性倒转,这已为大家所公认;但造成这种极性倒转的原因,则是迄今未能很好解答的一个难题.基于地球磁场的发电机效应理论和星地碰撞的动力效应研究,探讨了外星撞击地球造成地磁场极性倒转的可能性.研究表明,当外星沿与地球自转的正逆不同方向撞击地球时引起的地球转速快慢变化,可导致地球内部核、幔圈层之间的转速相对快慢关系(相对运动方向)发生改变,从而受其控制的液核涡旋方向及相应的地磁场方向也会随之改变,于是就形成地磁极性倒转.这是一个新的思路,它给地磁极性倒转提出了一个简明的动力机制解释.
It is generally acknowledged that geomagnetic polarity has reversed many times in geological history. However, the cause has been unknown up to now. Based on the theory of a generator effect for the formation of the Earth's magnetic field, and the dynamic effect of a collision with a celestial body, the possibility of a geomagnetic polarity reversal caused by the collision of an asteroid with the Earth is considered in this paper. When a celestial body collides with the Earth in a direction positive or negative to the rotation of the Earth, the rotation speed of the Earth could be quickened or slowed. This could change the direction of the relative movement between Earth's core and mantle. Consequently, the direction of the vortex movement in the liquid core and the geomagnetic field may change, therefore realizing geomagnetic polarity reversal. This new concept gives a simple and clear explanation for the dynamic cause of geomagnetic polarity reversal.
出处
《地球科学(中国地质大学学报)》
EI
CAS
CSCD
北大核心
2005年第3期371-376,共6页
Earth Science-Journal of China University of Geosciences
关键词
地球磁极倒转
成因
星地碰撞
Earth (planet)
Earth sciences
Magnetic fields