{"id":140456,"date":"2025-11-18T02:20:10","date_gmt":"2025-11-18T02:20:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/140456\/"},"modified":"2025-11-18T02:20:10","modified_gmt":"2025-11-18T02:20:10","slug":"earths-tilt-has-shifted-31-5-inches-and-heres-what-caused-it","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/140456\/","title":{"rendered":"Earth\u2019s Tilt Has Shifted 31.5 Inches\u2014and Here\u2019s What Caused It"},"content":{"rendered":"

Earth\u2019s rotation is not perfectly stable, and scientists have long known that mass redistribution\u2014like melting glaciers\u2014can affect the way our planet spins. But a new study published in Geophysical Research Letters has pinpointed a more immediate trigger: the enormous volumes of groundwater being removed for irrigation and urban use, especially in certain midlatitude regions. Between 1993 and 2010, an estimated 2,150 gigatons of groundwater were pumped, eventually making their way into the oceans.<\/p>\n

The consequences are twofold: not only does this contribute to global sea-level rise\u2014about 0.24 inches over the period studied\u2014but it also alters the Earth\u2019s rotational pole, the axis around which the planet spins. This shift, while imperceptible to us day to day, is a stark example of how deeply human activity is entwined with the mechanics of the planet itself.<\/p>\n

Pumping Groundwater Pushes the Planet off Balance<\/p>\n

The study<\/a>, led by Ki-Weon Seo, a geophysicist at Seoul National University, provides the most precise estimate to date of how human water use affects the Earth\u2019s axis. Speaking about the findings, Seo explained that \u201camong climate-related causes, the redistribution of groundwater actually has the largest impact on the drift of the rotational pole.\u201d His team used observational data between 1993 and 2010 to simulate water movement and its effects on Earth\u2019s spin.<\/p>\n

The only model that matched the observed drift was the one that factored in the 2,150 gigatons of extracted groundwater, confirming that water removal was the primary driver of the shift. This redistribution of mass acts similarly to adjusting weight on a spinning top: \u201cthe Earth spins a little differently as water is moved around,\u201d the study authors note<\/a>.<\/p>\n

These findings build on previous research from NASA in 2016, which had already demonstrated that water distribution can affect Earth\u2019s rotation. But Seo\u2019s study quantifies that effect with hard numbers, turning a previously observed trend into a clearly measurable outcome.<\/p>\n

\"GlobalGlobal mean sea level (GMSL) contributions from the Antarctic ice sheet (AIS) (a), Greenland ice sheet (GrIS) (b), mountain glaciers (c), soil moisture (d), artificial reservoirs behind dams (e) and groundwater (f). Note differences in the vertical scales \u2013 \u00a9 AGU<\/p>\n

Sea-Level Rise and Groundwater Loss Are Now Inseparable<\/p>\n

Once pumped from aquifers and used for agriculture or human consumption, groundwater doesn\u2019t disappear\u2014it ends up in the ocean, adding to rising sea levels. The study calculated this contribution at 0.24 inches over the 17-year period. While this might seem small, it\u2019s part of a complex, accelerating pattern that amplifies global climate impacts.<\/p>\n

According to NASA<\/a>\u2019s Surendra Adhikari, who contributed to the earlier 2016 study<\/a>, this new research is significant because \u201cthey\u2019ve quantified the role of groundwater pumping on polar motion, and it\u2019s pretty significant.\u201d It also provides a rare look into how terrestrial water storage changes translate into global environmental consequences.<\/p>\n

Critically, the impact depends heavily on where the water is being moved from. The redistribution from midlatitude areas\u2014especially western North America and northwestern India\u2014was found to have the most influence on the shift in Earth\u2019s axis, due to the geographical positioning and volume of extraction.<\/p>\n

\"(a)(a) Individual contributors to the PM excitation trend. (b) Sum of PM excitation trend contributors with (solid blue) and without (dashed blue) groundwater depletion. Red arrow is the observed PM excitation \u2013 \u00a9 AGU<\/p>\n

Tracking Earth\u2019s Pole Movement Offers a Window Into Water Use<\/p>\n

Observing how Earth\u2019s pole moves is no longer just a geophysical curiosity\u2014it\u2019s a practical tool for understanding water storage changes on a continental scale. \u201cObserving changes in Earth\u2019s rotational pole is useful,\u201d Seo stated, \u201cfor understanding continent-scale water storage variations.\u201d<\/p>\n

This approach opens the door for historical analysis, allowing researchers to dig deeper into decades of data and trace how human activity has steadily influenced the planet\u2019s orientation. It could also enhance future water management strategies by showing where withdrawals are having the greatest planetary impact.<\/p>\n","protected":false},"excerpt":{"rendered":"Earth\u2019s rotation is not perfectly stable, and scientists have long known that mass redistribution\u2014like melting glaciers\u2014can affect the…\n","protected":false},"author":2,"featured_media":140457,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[273,111,139,69,147],"class_list":{"0":"post-140456","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-environment","9":"tag-new-zealand","10":"tag-newzealand","11":"tag-nz","12":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/140456","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=140456"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/140456\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/140457"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=140456"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=140456"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=140456"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}