Groundwater Use and Global Change: How Humans are Shifting Earth’s Axis”
There is more water below the surface of the Earth than there are rivers and lakes worldwide.
The vast majority of the freshwater on the world comes from this groundwater. However, groundwater is being drained more quickly than it naturally recharges in many parts of the world.
According to a recent study, humans are extracting so much groundwater that it is really tilting the planet’s axis and not just raising sea levels.
How Groundwater Depletion Affects Earth’s Rotational Pole?
The rotational pole of the Earth often shifts and moves by a few meters annually.
The melting of snow and ice in the Northern Hemisphere each spring, which drastically alters the distribution of water mass on Earth, is one of many causes that cause this axial wobble.
Redistribution of water mass occurs when groundwater is extracted. Groundwater naturally resides beneath continents, but after extraction, around 80% makes its way to the ocean through rivers, moving all that water mass from the continents of Earth to its oceans.
And from 1993 to 2010, groundwater extraction led to the Earth’s rotational pole drifting by 64.16 degrees east at a rate of roughly 4.36 centimeters per year, according to a study published in the journal Geophysical Research Letters in June.
Comparatively, a different research found that, after the 1990s, the glaciers’ increased melting caused the poles to migrate east by around 26 degrees at a pace of 3.28 milliarcseconds (or 9.84 millimeters).
According to one of the researchers, this contribution of a few millimeters from groundwater depletion is unimportant because Earth’s rotational pole periodically drifts by several meters every year.
“What we discovered in this investigation concerning the pole’s drift would be insignificant in comparison to such oscillations of several meters. Therefore, at this time, we wouldn’t worry about it, according to Ki-Weon Seo, a geophysicist and associate professor in Seoul National University’s Department of Earth Science Education. The spinning pole, he said, frequently returns to its original places.
However, the part that groundwater plays in the rise in sea level is cause for alarm.
Why Humans Pump So Much Groundwater and How It Harms the Earth?
Nearly half of all drinking water worldwide comes from groundwater, which is also used for around 40% of global irrigation.
Unsustainable extraction might endanger aquatic habitats, result in water shortages, and raise sea levels.
Simply said, because water is moving from the continents to the oceans as a result of groundwater depletion, sea levels are rising.
According to a recent study, the worldwide sea level rose 6.24 millimeters between 1993 and 2010 as a result of groundwater depletion. This is crucial since it is estimated that the shoreline will recede by an average of 1.5 meters for every millimeter the sea level rises.
Another study discovered that excessive groundwater pumping might also reduce the water flow from natural streams. Since groundwater naturally feeds streams, it can reduce or even stop streamflow when groundwater levels fall as a result of human extraction.
The numerous ecosystems that depend on water flow in and around streams are consequently put in danger.
Without improved management, it is predicted that between 42% and 79% of all groundwater pumping basins won’t be able to support healthy ecosystems by 2050.