According to a study published on May 8, 2025, all major US cities are sinking. Lead author of the study, Leonard Ohenhen, had problems with his internet connection yesterday, but we have rescheduled our interview with him and we will be back on Monday 19. Don’t miss it! Watch in the player above or on YouTube.
No hype. Just real science, powered by real people. That’s you.
All major US cities are sinking
A study of the 28 most populous cities in the United States found they are all sinking. These cities are home to some 34 million people, or about 12% of the total U.S. population. Researchers at Virginia Tech said on May 8, 2025, that in 25 of 28 cities, at least 65% of the land is sinking. The major cause of the sinking is groundwater extraction.
As cities extract groundwater for human use, if the aquifer is not soon replenished, the spaces left behind compact. And that causes the ground to sink. As city populations continue to grow, and some places experience climate-induced droughts, the scientists said the problem will get worse.
The researchers published their peer-reviewed study in the journal Nature Cities on May 8, 2025.
How much are cities sinking?
The researchers said some urban areas are sinking by 2 to 10 millimeters, or 0.08 to 0.4 inches per year. That doesn’t sound like much, does it? Yet the effects are still serious. Lead author Leonard Ohenhen, a former Virginia Tech graduate student and now a postdoctoral researcher at the Columbia Climate School’s Lamont-Doherty Earth Observatory, said:
Even slight downward shifts in land can significantly compromise the structural integrity of buildings, roads, bridges and railways over time.
The difference makes a difference
Some areas of cities are sinking faster than others, and that’s a problem. The researchers – who used satellites to take precisely accurate measurements of the land – said the unequal sinking of the land was one of the most harmful effects. The good news is that only 1% of the land area in these cities have enough differential motion to affect buildings, roads and structures. The bad news is that these areas tend to be in the densely populated urban cores. Co-author Manoochehr Shirzaei at Virginia Tech said:
The latent nature of this risk means that infrastructure can be silently compromised over time with damage only becoming evident when it is severe or potentially catastrophic. This risk is often exacerbated in rapidly expanding urban centers.
Texas cities have particular problems
Houston is the fastest-sinking city. More than 40% of its land has been sinking at a rate of more than 5 millimeters (about 1/5 inch) per year. And 12% of Houston is sinking at twice that rate. But the news is not good for other Texas cities, either. Dallas and Forth Worth are not far behind. San Antonio and Austin’s highest risk areas are in their dense urban cores. One of the reasons Texas sees more sinking is because the problem is made worse due to extractions of oil and gas.
Other sources of sinking
Extraction of groundwater is the cause of about 80% of the sinking. Oil and gas extraction is also one of the factors. But there are other factors as well. When the glaciers advanced over North America some 20,000 years ago, the weight of the ice pressed down on some areas and lifted others. Some of those lifted areas are still settling since the ice retreated. And then there’s the weight of the skyscrapers and other buildings themselves. They’re also contributing to the sinking of some cities.
What can be done as cities are sinking?
The researchers said that monitoring the sinking land was key for urban planning. Some steps to mitigate the risk would include groundwater management, planning for more resilient infrastructure and long-term monitoring. Flooding resulting from the sinking land can be mitigated by raising the land in areas and adding more drainage and green infrastructure to absorb the water. The city cores that are most subject to tilting land can retrofit structures, adjust their building codes and limit building in the worst areas. Ohenhen said:
As opposed to just saying it’s a problem, we can respond, address, mitigate, adapt. We have to move to solutions.
Bottom line: A new study shows that all major U.S. cities are sinking. Groundwater extraction is the number one reason, along with some other factors. See where the problem is the worst.
Source: Land subsidence risk to infrastructure in US metropolises
Read more: Here are the US cities most vulnerable to space weather
The post Big cities are sinking in the US. Is yours one? first appeared on EarthSky.
from EarthSky https://ift.tt/aP1jH3k
According to a study published on May 8, 2025, all major US cities are sinking. Lead author of the study, Leonard Ohenhen, had problems with his internet connection yesterday, but we have rescheduled our interview with him and we will be back on Monday 19. Don’t miss it! Watch in the player above or on YouTube.
No hype. Just real science, powered by real people. That’s you.
All major US cities are sinking
A study of the 28 most populous cities in the United States found they are all sinking. These cities are home to some 34 million people, or about 12% of the total U.S. population. Researchers at Virginia Tech said on May 8, 2025, that in 25 of 28 cities, at least 65% of the land is sinking. The major cause of the sinking is groundwater extraction.
As cities extract groundwater for human use, if the aquifer is not soon replenished, the spaces left behind compact. And that causes the ground to sink. As city populations continue to grow, and some places experience climate-induced droughts, the scientists said the problem will get worse.
The researchers published their peer-reviewed study in the journal Nature Cities on May 8, 2025.
How much are cities sinking?
The researchers said some urban areas are sinking by 2 to 10 millimeters, or 0.08 to 0.4 inches per year. That doesn’t sound like much, does it? Yet the effects are still serious. Lead author Leonard Ohenhen, a former Virginia Tech graduate student and now a postdoctoral researcher at the Columbia Climate School’s Lamont-Doherty Earth Observatory, said:
Even slight downward shifts in land can significantly compromise the structural integrity of buildings, roads, bridges and railways over time.
The difference makes a difference
Some areas of cities are sinking faster than others, and that’s a problem. The researchers – who used satellites to take precisely accurate measurements of the land – said the unequal sinking of the land was one of the most harmful effects. The good news is that only 1% of the land area in these cities have enough differential motion to affect buildings, roads and structures. The bad news is that these areas tend to be in the densely populated urban cores. Co-author Manoochehr Shirzaei at Virginia Tech said:
The latent nature of this risk means that infrastructure can be silently compromised over time with damage only becoming evident when it is severe or potentially catastrophic. This risk is often exacerbated in rapidly expanding urban centers.
Texas cities have particular problems
Houston is the fastest-sinking city. More than 40% of its land has been sinking at a rate of more than 5 millimeters (about 1/5 inch) per year. And 12% of Houston is sinking at twice that rate. But the news is not good for other Texas cities, either. Dallas and Forth Worth are not far behind. San Antonio and Austin’s highest risk areas are in their dense urban cores. One of the reasons Texas sees more sinking is because the problem is made worse due to extractions of oil and gas.
Other sources of sinking
Extraction of groundwater is the cause of about 80% of the sinking. Oil and gas extraction is also one of the factors. But there are other factors as well. When the glaciers advanced over North America some 20,000 years ago, the weight of the ice pressed down on some areas and lifted others. Some of those lifted areas are still settling since the ice retreated. And then there’s the weight of the skyscrapers and other buildings themselves. They’re also contributing to the sinking of some cities.
What can be done as cities are sinking?
The researchers said that monitoring the sinking land was key for urban planning. Some steps to mitigate the risk would include groundwater management, planning for more resilient infrastructure and long-term monitoring. Flooding resulting from the sinking land can be mitigated by raising the land in areas and adding more drainage and green infrastructure to absorb the water. The city cores that are most subject to tilting land can retrofit structures, adjust their building codes and limit building in the worst areas. Ohenhen said:
As opposed to just saying it’s a problem, we can respond, address, mitigate, adapt. We have to move to solutions.
Bottom line: A new study shows that all major U.S. cities are sinking. Groundwater extraction is the number one reason, along with some other factors. See where the problem is the worst.
Source: Land subsidence risk to infrastructure in US metropolises
Read more: Here are the US cities most vulnerable to space weather
The post Big cities are sinking in the US. Is yours one? first appeared on EarthSky.
from EarthSky https://ift.tt/aP1jH3k
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