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According to a study, humans have pumped too much groundwater out of Earth to the extent that we have altered the Earth's axial precession.
In an article published in the journal Geophysical Research Letters, researchers have found that the axial precession around our planet has drifted about 31 inches eastward from 1993 to 2010 due to groundwater depletion. This has also led to rising sea levels.
Essentially, the position of Earth's axial precession relative to the crust may be affected by the distribution of water mass across the planet.
Ki-Weon Seo, a geophysicist at Seoul National University (South Korea), who led the research team, stated: 'Earth's axial precession is indeed changing significantly.'
'Our study indicates that among the climate-related factors, groundwater distribution actually has the greatest impact on the precession rate.'
Scientists discovered the potential of water to alter Earth's rotation in 2016. However, the specific impact of groundwater on these changes remains unclear to this day.
In the latest study, researchers modeled the observed changes in axial drift and water motion. Initially, the models only accounted for ice sheets and glaciers. Subsequently, the authors explored different scenarios related to groundwater redistribution.
The model only matches the observed polar drift from 1993 to 2010 if scientists consider 2,150 trillion tons of redistributed groundwater. Excluding the groundwater pumped from beneath Earth's surface, this model deviates by 31 inches (or 1.7 inches annually).
The figure of 2,150 gigatons - equivalent to a global sea level rise of 0.23 inches - stems from previous estimates by scientists regarding groundwater extraction over a 17-year period from 1993 to 2010. However, direct observational evidence demonstrates a margin of error in this estimate.
The model in the latest study - incorporating the redistribution of water from groundwater sources to the ocean - has provided independent confirmation of this estimate.
Groundwater depletion, linked to excessive pumping from sources like aquifers, exceeds the replenishment from natural sources.
This groundwater source is utilized for agricultural purposes as well as supplied to urban areas. Once this groundwater is extracted, it may find its way into the ocean through runoff or through the processes of evaporation and precipitation.
Refer to Newsweek
