reversal n. 1.顛倒,倒轉(zhuǎn),反轉(zhuǎn),逆轉(zhuǎn),反向;反復。 2.【法律】撤消。 3.【攝影】正負片之間的轉(zhuǎn)換。 That would be a reversal of the order of host and guest. 這就主客顛倒了。 a reversal of wind 風向突然逆轉(zhuǎn)。 a thrust reversal 【火箭】推力反向裝置。
The last geomagnetic reversal for earth was about 780 , 000 years ago 地球上最后一次地磁倒轉(zhuǎn)大約是78萬年前。
百科解釋
A geomagnetic reversal is a change in the Earth's magnetic field such that the positions of magnetic north and magnetic south are interchanged. The Earth's field has alternated between periods of normal polarity, in which the direction of the field was the same as the present direction, and reverse polarity, in which the field was the opposite.