New research reveals that the massive weight of water stored behind thousands of dams around the world has caused Earth’s poles to “wander” away from the planet’s rotational axis, resulting in a total shift of 3.7 feet between 1835 and 2011.
Scientists have found that large dams redistribute mass globally, shifting the position of Earth’s crust relative to the mantle, which in turn affects the location of the poles. The study used computer calculations and modeling to examine the impact of 6,862 dams on Earth’s poles during this period.
The research found two distinct phases of polar wander: one from 1835 to 1954, caused by large-scale dam construction in North America and Europe, resulting in a 8-inch shift towards the 103rd meridian east. The second phase, from 1954 to 2011, reflected expansive dam construction in East Africa and Asia, leading to a 22-inch shift towards the 117th meridian west.
The study’s lead author, Natasha Valencic, notes that while the impact on Earth’s processes is relatively small, the effect on sea levels is significant. The team found that dams block about a quarter of the water that would otherwise reach the oceans, influencing global sea levels.
This new research highlights the need for scientists to account for dams in their sea level rise projections, as they can significantly affect local sea levels.
Source: https://www.livescience.com/planet-earth/dams-around-the-world-hold-so-much-water-theyve-shifted-earths-poles-new-research-shows