{"id":8222,"date":"2025-07-14T04:18:04","date_gmt":"2025-07-14T04:18:04","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/8222\/"},"modified":"2025-07-14T04:18:04","modified_gmt":"2025-07-14T04:18:04","slug":"human-constructed-dams-have-shifted-the-earths-poles-scientists-say","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/8222\/","title":{"rendered":"Human-Constructed Dams Have Shifted the Earth\u2019s Poles, Scientists Say"},"content":{"rendered":"

Humans have built so many dams around the world that the Earth\u2019s poles have wandered away from the planet\u2019s rotational axis, new research suggests.<\/p>\n

Over the last 200 years, humans have constructed nearly 7,000 massive dams, impounding enough water to nudge the Earth\u2019s poles by about three feet (one meter) and cause a 0.83-inch (21-millimeter) drop in global sea levels, according to a new study in Geophysical Research Letters<\/a>.<\/p>\n

This drift is possible because Earth\u2019s solid crust forms a hard shell around a molten layer of gooey magma. This means that whenever a significant amount of mass is redistributed across the planet\u2019s surface, the outermost rock layer wobbles, shifting relative to Earth\u2019s molten interior. When this happens, different areas on the Earth\u2019s surface end up directly over the planet\u2019s rotational axis. As a result, the planet\u2019s poles pass through different surface locations than before, a phenomenon known as true polar wander.<\/p>\n

\u201cAs we trap water behind dams, not only does it remove water from the oceans\u2014thus leading to a global sea level fall\u2014it also redistributes mass around the world,\u201d Natasha Valencic, a graduate student at Harvard University and lead author of the new study, said in a statement<\/a>.<\/p>\n

In the study, Valencic and her team analyzed a previously published global database of dams to figure out their locations, the volume of water they store, and how that stored water has impacted Earth\u2019s mass distribution. Previously, the database revealed that 6,862 large dams built between 1835 and 2011 contributed to a decrease in sea levels. Collectively, these dams hold enough water to fill the Grand Canyon twice.<\/p>\n

The results showed that global dam-building has caused Earth\u2019s poles to shift in two phases. The first phase, from 1835 to 1954, coincided with a boom in dam construction in North America and Europe. These areas shifted toward the equator, and as a result, the North Pole moved about 8 inches (25 centimeters) toward the 103rd meridian east, a line that passes through Russia, Mongolia, and China.<\/p>\n

During the second wave of dam construction, between 1954 and 2011, most dams were built in Asia and East Africa. As a result, the North Pole shifted 22 inches (57 centimeters) toward the 117th meridian west, which passes through western South America and the South Pacific. Polar wander is not linear; instead, it follows a wobbly path, which is why the total shift does not add up precisely to 3.7 feet.<\/p>\n

While the results are relatively subtle, they highlight the need for researchers to account for water stored in dams when predicting future sea level rise. In the 20th century, global sea levels rose 4.7 to 6.7 inches (12 to 17 centimeters), but humans trapped about a quarter of that volume behind dams, according to Valencic.<\/p>\n

\u201cDepending on where you place dams and reservoirs, the geometry of sea level rise will change,\u201d she said. \u201cThat\u2019s another factor we need to consider, because these changes can be quite large and significant.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"Humans have built so many dams around the world that the Earth\u2019s poles have wandered away from the…\n","protected":false},"author":2,"featured_media":8223,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[32],"tags":[8318,8319,79,282],"class_list":{"0":"post-8222","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-hydroelectric-dams","9":"tag-planet-earth","10":"tag-science","11":"tag-water"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/8222","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=8222"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/8222\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/8223"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=8222"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=8222"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=8222"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}