Scientists Discover Earth’s Tilt Has Changed Due to Human Pumping of Groundwater
A recent study has revealed that Earth’s tilt has shifted by 31.5 inches (80 centimeters) between 1993 and 2010, and the cause is the massive amount of groundwater that humans have pumped from the planet’s interior.
During this period, humans extracted a staggering 2,150 gigatons of water from natural reservoirs in the Earth’s crust. To put this into perspective, if this amount of water were poured into the global ocean, its surface would rise by 0.24 inches (6 millimeters). The consequences of displacing such a significant volume of water have had an impact on the axis around which the planet spins.
Scientists reached this conclusion by creating models that simulated the changes in the position of Earth’s rotational pole. The rotational pole refers to the point at which the planet’s imaginary axis would protrude from its surface if it were a physical object. It’s important to note that the rotational pole is not the same as the geographical north and south poles and actually shifts over time, cutting through different areas of the planet’s crust at different points in time.
Previous research conducted in 2016 had already established that the rotational pole is influenced by climate-related processes, such as the melting of icebergs and the redistribution of water mass within them. However, the models did not perfectly align with observations until the researchers incorporated the effects of pumped-out groundwater. Without accounting for the groundwater extraction, the model was off by 31 inches (78.5 centimeters).
Ki-Weon Seo, a geophysicist at Seoul National University who led the study, emphasized the significance of groundwater redistribution on the drift of the rotational pole. Seo stated, “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 tilt of Earth’s axis can influence seasonal weather patterns on the planet’s surface. Consequently, scientists are now exploring whether shifts in the rotational pole could contribute to long-term climate change.
Seo highlighted the importance of monitoring changes in Earth’s rotational pole for understanding variations in continent-scale water storage. By analyzing polar motion data dating back to the late 19th century, researchers can potentially gain insights into changes in continental water storage over the past century. This information could shed light on hydrological regime changes resulting from a warming climate.
Overall, Earth’s rotational pole shifts several meters each year. The extent to which drained groundwater reservoirs contribute to this shift depends on their location. The study found that water extraction from mid-latitudes has the most significant impact on the planet’s tilt.
Managing the movement of groundwater globally could potentially help mitigate shifts in the rotational pole and the associated climate effects.
In conclusion, the study’s findings highlight the profound influence of human activities on Earth’s tilt. The extraction of groundwater has caused a significant shift in the planet’s rotational pole, which could have implications for climate change. Understanding and managing these changes are crucial for maintaining the stability of Earth’s axis and minimizing potential climate impacts.
Sources:
– Space.com
– Study by Ki-Weon Seo et al.
