Groundwater Pumping Alters Earth’s Rotation and Sea Levels, Study Reveals

Recent research published in the journal Geophysical Research Letters has highlighted the significant impact of groundwater pumping on the Earth’s tilt and rotation, as well as its contribution to rising sea levels. The study reveals that in less than two decades, the Earth has tilted 31.5 inches due to intensive groundwater extraction, which corresponds to increasing sea levels by 0.24 inches. Ki-Weon Seo, a geophysicist at Seoul National University and the lead author of the study, remarked, «Earth’s rotational pole actually changes a lot. Our study shows that among climate-related causes, the redistribution of groundwater actually has the largest impact on the drift of the rotational pole.»

The movement of Earth’s rotational pole is influenced by the distribution of water on the planet, which affects the distribution of mass. The study’s authors compared this effect to «adding a tiny bit of weight to a spinning top,» explaining that Earth begins to spin differently as water is redistributed. While NASA research in 2016 had previously indicated that water distribution could alter Earth’s rotation, the current study provides specific figures to substantiate this observation. «I’m very glad to find the unexplained cause of the rotation pole drift,» Seo stated, «On the other hand, as a resident of Earth and a father, I’m concerned and surprised to see that pumping groundwater is another source of sea-level rise.»

Analyzing data from 1993 to 2010, the study estimates that the extraction of approximately 2,150 gigatons of groundwater has led to the noted changes in Earth’s tilt. Most of the water extracted has been used for irrigation and human consumption before ultimately draining into oceans. Researchers designed models to simulate changes in Earth’s rotational drift and water movement, finding that only the models incorporating the 2,150 gigatons of groundwater redistribution produced results that matched observed drifts. Surendra Adhikari, a research scientist at NASA’s Jet Propulsion Laboratory involved with the 2016 study, emphasized the importance of the new findings. «They’ve quantified the role of groundwater pumping on polar motion,» Adhikari said in a news release, «and it’s pretty significant.»

The study further points out that the regions where water is being moved from and to are critical. Notably, significant water movement in regions like western North America and northwestern India has had a prominent effect on these changes. As the implications of water redistribution over a relatively recent period become clearer, there is potential to examine historical data for trends and a deeper understanding of groundwater movement’s effects.

While these findings may aid conservationists in efforts to mitigate ongoing climate challenges, Seo suggests that tracking changes in Earth’s rotational pole could assist in understanding variations in continental water storage. Such insights may prove helpful as the global community seeks to implement effective conservation strategies over time.