Earth’s Tilt is Being Altered as Excessive Groundwater Extraction by Humans Persists

By extracting water from underground sources, humans have caused a substantial shift in the Earth’s position, tilting it about 80 centimeters (31.5 inches) eastward in the past three decades.

During a process known as polar motion, the Earth’s rotational poles, which are the points around which the planet rotates, move in relation to the surface due to the distribution of Earth’s mass. This phenomenon can also be observed on a smaller scale during a hammer throw competition, where the athlete wobbles around the center of rotation due to the swirling mass of the hammer.

Over long periods of time, various factors such as the gravitational pull of the Sun and Moon, the changing size of ice sheets, and the movement of continents can cause mass redistribution and shift the Earth’s axis. However, human activities can also lead to significant changes within a shorter timeframe.

In a 2016 study, researchers argued that the anomalous eastward shift of the rotational poles over the past 115 years was a result of anthropogenic climate change. As global temperatures rise due to increasing greenhouse gas levels in the atmosphere, melting ice sheets and glaciers cause sea levels to rise, leading to the redistribution of water and a shift in the Earth’s center of rotation.

However, melting ice and snow alone cannot fully explain the observed polar shift.

In a new study, scientists conducted models to simulate the drift of the Earth’s axis and the movement of water. Initially, they only considered ice sheets and glaciers, but they later incorporated different scenarios of groundwater redistribution.

“Our study reveals that among climate-related factors, the redistribution of groundwater has the most significant impact on the drift of the rotational pole,” stated lead author Ki-Weon Seo.

Groundwater has been extensively used for irrigation, drinking water, and industrial activities in modern times. Previous estimates by scientists suggested that humans pumped around 2,150 gigatons of groundwater, which is equivalent to over 6 millimeters (0.24 inches) of sea-level rise, between 1993 and 2010.

The extraction of groundwater and surface runoff add mass to the oceans, resulting in lighter continents, particularly in the northern hemisphere.

In the model, the location of the groundwater played a significant role in its potential to influence polar drift. The redistribution of water from mid-latitudes had a more pronounced effect on the rotational pole. During the study period, the largest amount of water was redistributed in western North America and northwestern India, both located at mid-latitudes.

Normally, the rotational poles undergo natural variations of several meters within a year, so the changes caused by groundwater pumping do not pose any immediate catastrophic risks. Nevertheless, this new model provides a valuable tool for studying humanity’s historical usage of groundwater.

“Monitoring changes in Earth’s rotational pole helps in understanding variations in continental-scale water storage,” explained Seo. “Polar motion data dates back to the late 19th century, and we can potentially use this data to analyze changes in continental water storage over the past century. Did hydrological patterns undergo any significant alterations due to climate warming? Polar motion might hold the answer.”

The study titled “Drift of Earth’s Pole Confirms Groundwater Depletion as a Significant Contributor to Global Sea Level Rise 1993–2010” was published in the journal Geophysical Research Letters (2023). Material provided by Rebecca Dzombak for the American Geophysical Union.

Denial of responsibility! TechCodex is an automatic aggregator of the all world’s media. In each content, the hyperlink to the primary source is specified. All trademarks belong to their rightful owners, and all materials to their authors. For any complaint, please reach us at – [email protected]. We will take necessary action within 24 hours.