The world doesn’t work properly anymore, and it’s Man’s fault. Our activity has caused, in two simultaneous ways, a displacement of almost one meter in the axis of rotation of the earth. If the role of ice melting was already a known element, researchers from the University of Seoul have just shown that the excessive pumping of water installed in underground aquifers also plays an important role. Conclusions shared on June 15 within the review Geophysical Investigation Letters.
Between 1993 and 2010, humanity pumped 2,150 gigatons of water into its underground reservoirs, mostly for agriculture. This single disturbance shifted the earth’s axis of rotation by 80 centimeters from the Greenwich meridian. This equates to about 4 centimeters of change per year.
The melting of the ice, in turn, has caused a displacement of about 7 centimeters per year. These two factors combined, the variation becomes much more important than the natural oscillation of the blue planet.
To help visualize the link between these water displacements and the change in the axis of rotation, the South Korean researchers use a revealing metaphor:
“[C’est] Like adding a little weight to a top, the Earth spins a little differently when you move the water.”
Rising sea levels
The study highlights that two areas are particularly affected by overpumping, northwestern India and western North America. These two territories are experiencing “significant reductions in the storage of groundwater”, to meet industrial, textile, agricultural needs and the consumption of drinking water.
Once the water has been brought by man, a part evaporates, another seeps into the ground. The rest is transported by rivers and ends up in the oceans. These have been mechanically inflated and have seen their level increase. On average, the sea level has risen 6.24 millimeters in the last 20 years.
No impact on seasons “for now”
Are these transformations permanent? Lead author Ki-Weon Seo believes it would take several decades of groundwater conservation policies to be reversed.
Regarding the consequences of these changes, questioned by Release, geophysicist Kristel Chanard judged that the change in our planet’s axis of rotation “at the moment” is not massive enough to disturb the cycle of the seasons. But her vision of the future is pessimistic.
“This phenomenon may not evolve in the right direction in the future, it must be monitored and better understood,” warns the geophysicist.
Another black point: even if humanity stopped overexploiting its underground water reserves, they would not return to their original state. The cavities emptied of their water eventually collapse and can therefore no longer be filled.
Source: BFM TV
