Guwahati, July 11 -- The construction of thousands of dams around the world since the 19th century has caused Earth's poles to shift by more than 3.7 feet, according to new research published in the journal Geophysical Research Letters.

The study suggests that dams, which store massive volumes of water, have redistributed the planet's mass enough to affect the orientation of Earth's rotation axis-a phenomenon known as "true polar wander." This occurs when the position of the Earth's crust shifts relative to the mantle, causing the poles to move.

Researchers examined the impact of 6,862 dams built between 1835 and 2011. They found that storing water behind these dams not only led to a measurable decrease in global sea levels-by 0.9 inche...