Scientists at Harvard University have determined that extensive dam construction worldwide, leading to a significant redistribution of water masses, has caused the Earth`s crust`s rotational axis to shift by approximately one meter. This discovery, made by a team led by geophysicist Natasha Valentich, was published in the prestigious journal Geophysical Research Letters (GRL).
The accumulation of water in vast reservoirs has not only altered the mass balance on the planet`s surface but has also contributed to a 21-millimeter reduction in global ocean levels. The immense volume of water retained behind dams effectively “pulled” the Earth`s rotating outer shell, causing the North Pole`s position on the planet`s surface to visibly shift: initially eastward, and subsequently westward.
The specialists emphasize that while the true magnetic North Pole in space remains unchanged, it is the Earth`s crust itself that has undergone this displacement. This phenomenon is scientifically known as “true polar wander.” Interestingly, the substantial amount of water held back by existing dams already accounts for approximately a quarter of the projected global sea level rise in the 21st century—roughly 1.2 millimeters per year—thereby partially mitigating some effects of climate change.
Given these profound findings, scientists are now urging that the impact of such large-scale engineering projects be meticulously factored into future assessments concerning sea level changes and the intricate dynamics of the Earth`s magnetic poles. The strategic location and sheer scale of new reservoirs, they warn, could significantly influence these critical global processes.
This research builds upon earlier findings; in April, other scientists had previously connected the acceleration of Earth`s rotation to the loss and redistribution of soil moisture, identifying it as another significant factor contributing to changes in the planet`s overall mass balance.
