A recent study has revealed that Chicago is one of the fastest-sinking major cities in the United States, with researchers from Virginia Tech finding the city is subsiding at an alarming rate of 2.32 millimeters per year.
This places Chicago just behind Houston, Fort Worth, Dallas, and New York City on the list of the top five cities experiencing land subsidence.
While the risk of the city falling into Lake Michigan is not imminent, the gradual sinking could have serious implications for the structural integrity of buildings and infrastructure.
Researchers have mapped sinking areas using satellite radar measurements, and their study, published in April in the journal Nature Cities, highlights that about 10% of Chicago’s land is sinking at rates exceeding 3 millimeters annually.
Leonard Ohenhen, the study’s lead author, emphasized the potential dangers, stating that even slight shifts in land levels could compromise roads, bridges, and buildings over time.
Alessandro Rotta Loria, an associate professor at Northwestern University, added that such subsidence might lead to buildings tilting or cracking.
The principal factor driving land subsidence in Chicago is groundwater extraction.
While residents primarily obtain their drinking water from Lake Michigan, other less direct contributors to the sinking phenomenon have been identified.
One significant factor is the ongoing glacial isostatic adjustment — a geological process that has been occurring since the last ice age.
Approximately 20,000 years ago, a massive glacier covered the northern United States and Canada, imparting extreme pressure on the Earth’s crust.
As the glacier melted, this pressure was alleviated, and the Earth’s crust began to adjust back to its original state, causing the land to slowly sink.
Chicago, located at the edge of the last glacial intrusion, experienced less pressure than northern areas, and as the mantle redistributes, the city is feeling the impact of this geological shift.
The study indicates that Chicago is sinking faster than all major East Coast cities, except for New York.
In an additional study released in 2023, researchers from Northwestern University explored the effects of underground climate change, drawing connections between urban infrastructure and rising subsurface temperatures.
Hard surfaces like buildings and roads absorb heat, creating an urban heat island effect that elevates temperatures both above and below ground.
Rotta Loria introduced the concept of “subsurface warming,” referring to rising underground temperatures that lead to ground deformations.
He noted that buildings, roads, and transit systems contribute heat below the surface through energy usage and stored heat emissions.
Using temperature sensors and 3D modeling, Rotta Loria’s research predicts that ground temperatures could lead to land sinking by up to 8 millimeters and swelling by 12 millimeters over the next three decades, largely depending on soil composition.
Given that much of Chicago’s land is clay-based, this makes it particularly sensitive to temperature shifts, causing significant contraction and expansion in response to heat.
While Chicago has not experienced significant groundwater depletion compared to other cities, the movement of groundwater — influenced by subsurface warming — could still contribute to land subsidence.
To mitigate these subsurface warming effects, Rotta Loria suggests utilizing geothermal technology to repurpose excess heat and incorporating thermal insulation in buildings to minimize heat loss underground.
As Chicago grapples with the implications of land deformation, experts warn that while immediate collapse is unlikely, the long-term structural integrity of buildings could be compromised if the issue is not addressed.
Rotta Loria pointed to instances of operational issues in multiple Chicago buildings over recent decades, where foundations settled excessively, though he couldn’t confirm if these were directly related to ground deformations.
Echoing the importance of proactive measures, Hensel expressed optimism that increased awareness could help avert a crisis in the future.
“Urban development often comes with challenges, yet addressing them early could prevent potential disasters down the line,” he warned.
As threatened cities across the U.S. continue to face environmental pressures, understanding the complex interplay between urbanization and geological changes will become increasingly critical for both infrastructure maintenance and city planning strategies.
image source from：https://blockclubchicago.org/2025/06/03/chicago-is-sinking-land-under-our-feet-is-retreating-more-than-most-cities/
