The ground underneath the Chicago city is gradually deforming due to “underground climate change”, scientists are claiming.
According to the latest study, this phenomenon is called “subsurface heat islands” and is caused by heat released by buildings and subterranean transportation such as subway systems.
The research argues that rising temperatures are causing land to undergo massive changes in urban areas and that it could adversely affect buildings and infrastructure, threatening long-term durability.
“The denser the city, the more intense is underground climate change,” said lead study author Alessandro Rotta Loria, an assistant professor of civil and environmental engineering at Northwestern University in Evanston, Illinois, reports CNN.
He said that soil, rocks and construction materials are being impacted by temperature variations.
For example, the ground underneath buildings can contract when heated, causing unwanted settlement, Loria said.
“Deformations caused by underground climate change are relatively small in magnitude, but they continuously develop,” he said.
“Over time, they can become very significant for the operational performance of civil infrastructure like building foundations, water retaining walls, tunnels and so on.”
New York was also found to be sinking
Notably, it comes after scientists announced New York may be sinking under the weight of its own buildings back in May —with 1.68 trillion pounds pushing down on the ground beneath.
The study, which was published this month in the Communications Engineering journal, came to the conclusion after observing the land changes for the past 25 years.
The researchers installed 150 temperature sensors across the Chicago Loop district, both above and below ground, and in a variety of places such as basements, tunnels and parking garages.
Sensors were also placed in Grant Park along Lake Michigan to compare temperatures from an unbuilt area with no excess heat coming from construction or transportation.
The data that was collected for the last three years showed that the ground under the Loop was up to 18 degrees Fahrenheit (10 degrees Celsius) warmer than the ground beneath the park.
“And the consequence of that is that at least a portion of the heat will diffuse towards the ground over time, and that’s the origin of the phenomenon,” Loria said.
Loria notes that underground climate change can cause issues such as groundwater contamination or problems with underground railways by making tracks prone to buckling or causing passengers to become ill due to excessive heat.
(With inputs from agencies)
