HOW GROUNDWATER CONTRIBUTE TO RISE IN SEA LEVEL, SHIFTING OF EARTH’S AXIS

Did you know that an estimated 2,150 gigatonnes of water have been pumped out between 1993 and 2010 which is enough water to fill Lake Victoria in Africa and contributed to six millimetres of sea level rise?

Scientists, in a findings of a research published in Geophysical Research Letters, a journal by the American Geophysical Union, have found that humans have pumped out so much groundwater from the earth in the past two decades that it has shifted the tilt of the Earth’s axis.

According to the findings, the Earth has tilted as much as 80 centimetres (31.5 inches) in just seven years (between 1993 and 2010), which has been attributed to humans pumping out groundwater and moving it elsewhere.

The phenomenon of water’s influence on Earth’s rotation was discovered in 2016 but until recent research, there was nothing known about the contribution of groundwater to these changes on the planet’s axis. 

The findings which have left scientists surprised and concerned seem to also reveal that the extracted water which ended up in the oceans also contributed to six millimetres of sea level rise, though validating this estimate is difficult.

The researchers first modelled the observed changes in the drift of Earth’s rotational pole and the movement of water with only ice sheets and glaciers and later with different scenarios of groundwater redistribution. It was found that the model only matched the observed polar drift once the researchers included 2150 gigatones of groundwater redistribution without which it was off by around 78.5 centimetres (31 inches), or 4.3 centimetres (1.7 inches) of drift per year. 

The study also noted the impact of the location of the groundwater on the change in the polar drift as most of the water was redistributed in western North America and northwestern India during the time period studied. Since both regions are at midlatitudes, researchers observed that redistributing water from the midlatitudes has a larger impact on Earth’s rotational pole.

Image Credit: NASA

Read more about the report here:

https://www.wionews.com/science/surprised-and-concerned-scientists-find-groundwater-extracted-by-humans-has-shifted-earths-tilt-606665