Excessive groundwater extraction has knocked Earth’s axis off-kilter

Groundwater pumped from the earth and moved elsewhere to quench the thirst of human activity has resulted in the Earth’s axis tilting nearly 80 cm to the east

Groundwater pumped from the earth and moved elsewhere to quench the thirst of human activity has resulted in the Earth’s axis tilting nearly 80 cm to the east, a study conducted between 1993 and 2010 has shown. 

Scientists estimated that nearly 2,150 gigatons of groundwater have been pumped and drained into the oceans, making it one of the important contributors to global sea-level rise. However, there was no direct observational proof that backed this estimate. 

Now, a study published in the Geophysical Research Letters has used the Earth’s rotational pole to determine the veracity of the estimate.

The Earth’s rotational pole is the point along which the planet rotates. This point, also called the axis of the Earth, moves in a process called polar motion which is when the Earth’s pole varies relative to the crust. 

Unlike a globe which has a fixed axis and rotates stably the Earth’s axis wobbles. It is more like a spinning top gone off-kilter where the Earth’s rotational pole tends to wander in a circular pattern several meters wide every year due to the weather, season changes, the molten core and even hurricanes. 

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Scientists have been able to track this motion by looking at astronomical phenomena such as centres of bright galaxies or quasars by comparing their changing positions in the sky as the Earth’s axis shifted.