北领地一位政府官员曾提议抽取地下水可能有助于稳定地球自转，防止地极反转。对此，古地磁学专家澄清了这一观点中存在的科学误区[1]。
专家指出，地球存在地理北极和磁北极两种不同的概念，其中地理极翻转在实际上不可能发生[1]。虽然磁极反转在地球历史上确实发生过，但这一过程与地表人类活动（如抽取地下水）无关[1]。磁极反转的发生机制源自距地表2,890至5,150公里的外核液态铁流动[1]。从1993年到2010年间，全球抽取的地下水使地理极每年偏移约4厘米[1]，但这种局部偏移与磁极反转的深层物理过程毫无关联。
根据地质记录，最后一次完整的磁极反转发生在大约780,000年前[1]，最近一次重大扰动是约41,000年前的拉尚普事件[1]。高分辨率沉积物记录表明，磁场反转过程需要数千年才能完成，全球平均耗时约7,000年[1]。一些科学家认为下一次反转可能在1,000至2,000年内发生[1]，而目前南大西洋存在称为南大西洋异常的弱磁场区域[1]。
A Northern Territory government official has proposed that extracting groundwater might help stabilize Earth's rotation and prevent polar reversal. However, a paleomagnetist has clarified the scientific distinctions and mechanisms at work.[1]
The expert explains that Earth has two distinct pole concepts: the geographic North Pole and the magnetic North Pole.[1] A geographic pole reversal is effectively impossible in practical terms, whereas magnetic pole reversals, though they have occurred throughout history, are unrelated to surface activities such as water pumping.[1] The mechanism behind magnetic reversals originates in the outer core's liquid iron circulation, located 2,890 to 5,150 kilometers below Earth's surface.[1]
Between 1993 and 2010, global groundwater extraction caused the geographic pole to shift approximately 4 centimeters annually.[1] The most recent complete magnetic pole reversal occurred roughly 780,000 years ago, with the most significant recent disturbance being the Laschamp excursion about 41,000 years ago.[1] High-resolution sediment records indicate that magnetic field reversals require thousands of years to complete, averaging around 7,000 years globally.[1] Some scientists suggest the next reversal could occur within 1,000 to 2,000 years, and a region of weakened magnetic field known as the South Atlantic Anomaly currently exists in the South Atlantic.[1]
