Earth’s Axis Tilted Noticeably Over Two Decades, and Now We Know Why
If you’re feeling a little off-balance, you can blame your fellow humans: Groundwater pumping caused the Earth to tilt 31.5 inches over a 17-year period, or about 1.8 inches per year.
According to recent media reports, including Popular science and USA Todaypumping 215 billion tons of groundwater from 1993 to 2010, tilting the Earth by more than two feet. (One gigaton of water represents approximately 2.2 trillion pounds of water, or 1 billion metric tons.) The study was originally Published in the journal Geophysical Research Letters Last June.
Most groundwater is pumped for agricultural irrigation and the water we use for drinking, bathing and other domestic and industrial purposes. The cause of this effect appears to be the redistribution of water from natural river channels.
The Earth is always tilted 23.5 degrees from its axis, which is why we have season and daylight saving time.
The pumped groundwater ends up in the ocean and contributes modestly to sea level rise. A more important cause of sea level rise is climate change caused by the burning of fossil fuels, which causes glaciers to melt and sea ice. In both cases, human activities affect the Earth’s water balance.
The study was led by Ki-Weon Seo of Seoul National University and tracked similar findings: Dating back to 2016 NASA.
“The Earth’s rotation pole actually changes quite a bit,” Xu said in a statement when the study was published. “Our study shows that among climate-related causes, groundwater redistribution actually has the greatest influence on the drift of the rotating pole.”
