A recent study titled ‘Drift of Earth’s Pole Confirms Groundwater Depletion as a Significant Contributor to Global Sea Level Rise 1993–2010’, was published in the journal Geophysical Research Letters.
- The study says that as humans pumped out around 2,150 gigatons of groundwater between 1993 and 2010, the planet’s axis has drifted at the rate of 4.36 cm per year towards the east.
Key points
- Earth spins around an imaginary axis which passes through the north pole, its centre of mass and the south pole — just like a top spins around its spindle.
- Scientists for years have known that the poles and the axis keep shifting naturally as the mass distribution in and on the planet changes. This phenomenon is known as “polar motion”.
- For instance, rocks slowly circulating inside Earth’s mantle causes the planet’s mass to shift, leading to a change in the position of the rotational axis.
- There are several other reasons responsible for polar motion like ocean currents and even hurricanes.
- But this phenomenon is also impacted by human activities.
- In 2016, a team of researchers demonstrated that climate-driven changes in water mass distribution, led by the melting of glaciers and ice in Greenland, can cause Earth’s axis to drift.
- Five years later, another study said climate change was causing the rotational axis to shift more than usual since the 1990s.
