Latest news with #groundwaterextraction
Yahoo
17-05-2025
- Science
- Yahoo
America's cities are sinking, and that could be a big problem
The Brief A new study finds all 28 of the most populated U.S. cities are sinking. At least 65% of the urban area is affected. Some cities are dropping by more than 5 millimeters per year. MILWAUKEE - Turns out that sinking feeling is not just your imagination. In fact, many of America's biggest cities are slowly sinking into the ground. What we know A major new study published in Nature Cities found that all 28 of the most populated U.S. cities are experiencing what's called land subsidence. Land subsidence is the gradual sinking of the Earth's surface. In all but three of those cities, at least 65% of the urban area is affected. In some cases, the land is dropping by more than five millimeters per year. That may not seem like much, but that could have a big impact over time. SIGN UP TODAY: Get daily headlines, breaking news emails from FOX6 News What we know According to the study, the leading cause is groundwater extraction. That is when a city pumps water from underground aquifers, leaving behind big empty spaces in the soil. That then causes the land above to collapse downward. This is especially common in fast-growing urban areas like Houston, Dallas and Phoenix. Milwaukee takes most of its water from Lake Michigan, but cities like Waukesha and Wauwatosa do rely on water from aquifers. Other factors that are also at play include oil and gas extraction, and what's known as natural post-glacial rebound in places that were once compressed by ancient ice sheets. Of course, there's also the weight of our cities themselves. Those buildings, roads, and infrastructure are all pressing down and, over time, add to the problem. Why you should care According to the study, over 30 million people live in subsiding areas. That includes almost 30 thousand buildings in zones where the risk of structural damage is high or very high. Sinking land doesn't just mean a few cracks in the sidewalk. It threatens roads, bridges, homes, water lines, and public safety. It also makes flooding worse, especially as climate change intensifies storms and sea-level rise. FREE DOWNLOAD: Get breaking news alerts in the FOX LOCAL Mobile app for iOS or Android What you can do There isn't much an average citizen can do, but researchers do say city planners need to start treating subsidence like the ticking time bomb that it is. That means using satellite and ground-level data to monitor land movement, updating building codes, and rethinking how we manage groundwater. Smart planning today could save billions in damage and make for a safer tomorrow. Want to read the full research article? Click here to learn more. The Source Information in this report is sourced from a study published in the Nature Cities online science journal, accessible through the link above.
Daily Mail
08-05-2025
- Science
- Daily Mail
34 million Americans reside in sinking urban areas, expert issues
Scientists have discovered that the 28 most populous cities in the US are sinking, with 34 million people living in the affected areas. Researchers found ongoing groundwater extraction for drinking water and other uses is the most common cause of the sinking, though other forces are at work in some places. The study, conducted by Columbia University, found that while coastal cities are at risk, some of the areas sinking fastest were actually landlocked cities such as Fort Worth and Dallas. But coastal Houston is the fastest-sinking city in the country, with almost half of its area dipping more than one fifth of an inch per year. Some spots are sinking even faster — up to 2 inches per year. Dallas and Fort Worth aren't far behind, sinking at rates of roughly 0.16 and 0.2 inch per year, respectively. The study also highlighted New York's LaGuardia Airport, parts of Las Vegas, Washington DC and San Francisco as rapidly sinking zones. The 28 cities are home to nearly tens of millions of people, and more than 60 percent if this total population lives in just eight cities: New York, Chicago, Los Angeles, Phoenix, Houston, Philadelphia, San Antonio and Dallas. The researchers note that these cities have seen more than 90 major floods within the last 25 years, and suggest that this is due in large part to the fact that they're sinking. 'As cities continue to grow, we will see more cities expand into subsiding regions,' said lead author Leonard Ohenhen, a postdoctoral researcher at the Columbia Climate School's Lamont-Doherty Earth Observatory. 'Over time, this subsidence can produce stresses on infrastructure that will go past their safety limit,' he added. Ohenhen and his colleagues used satellite data to map sinking down to the millimeter in all US cities with populations over 600,000. They also looked at the amount of groundwater pumping in affected counties and linked it to ground sinking. Coastal cities tend to be more prone to ground sinking due to the combined effects of groundwater pumping and sea level rise. But multiple interior cities, such as Denver, Oklahoma City and Nashville, are experiencing moderate sinking. Those three are sinking roughly 0.04 to 0.08 inch per year. About one percent of land in the 28 cities is experiencing sinking that could impact critical infrastructure such as buildings, roads and rail lines. Even though that percentage seems small, these areas tend to be located in the densest parts of these cities, which contain up to 29,000 buildings. From this perspective, the most hazardous cities are San Antonio, where one in 45 buildings are at 'high risk' of damage from ground sinking, Austin, Fort Worth, and Memphis. Across the US, and in interior cities especially, ground sinking is mainly driven by groundwater pumping, the researchers concluded. When water is extracted from aquifers made up of saturated fine-grained sediments and not replenished, the pore spaces between the sediment particles can collapse. This causes the lower layers of the aquifer to condense and become compacted, and results in sinkage at the surface, according to the researchers. In Texas, this is made even worse by oil and gas drilling, they explained in their report. And there are other factors at play too. Roughly 20,000 years ago, interior North America was covered by a towering ice sheet that made the land along its edges bulge upward. That ice sheet is long gone, but some of the bulges still exist, though they are subsiding at rates of 0.04 to 0.12 inch per year. This is adding to ground sinking observed in New York City, Indianapolis, Nashville, Philadelphia, Denver, Chicago and Portland, according to the researchers. The team published their findings in the journal Nature Cities on Tuesday. A 2023 study also found that the weight of buildings in densely urbanized areas may be contributing to ground sinking. Those researchers found that New York's more than one million buildings are pressing down on the Earth so hard that they have become an important factor in the city's subsidence. New construction may be playing a role too. A more recent study found that some buildings in Miami are sinking in part due to subsurface disruptions caused by buildings going up nearby. The researchers urge cities to use their data to develop mitigation strategies for ground sinking and flood risk. Want more stories like this from the Daily Mail? Hit the follow button above for more of the news you need.
Daily Mail
08-05-2025
- Science
- Daily Mail
Experts issue urgent warning after discovering 28 major US cities are SINKING... is your hometown at risk?
Scientists have discovered that the 28 most populous cities in the US are sinking, with 34 million people living in the affected areas. Researchers found ongoing groundwater extraction for drinking water and other uses is the most common cause of the sinking, though other forces are at work in some places. The study, conducted by Columbia University, found that while coastal cities are at risk, some of the areas sinking fastest were actually landlocked cities such as Fort Worth and Dallas. But coastal Houston is the fastest-sinking city in the country, with almost half of its area dipping more than one fifth of an inch per year. Some spots are sinking even faster — up to 2 inches per year. Dallas and Fort Worth aren't far behind, sinking at rates of roughly 0.16 and 0.2 inch per year, respectively. The study also highlighted New York's LaGuardia Airport, parts of Las Vegas, Washington DC and San Francisco as rapidly sinking zones. The 28 cities are home to nearly tens of millions of people, and more than 60 percent if this total population lives in just eight cities: New York, Chicago, Los Angeles, Phoenix, Houston, Philadelphia, San Antonio and Dallas. The researchers note that these cities have seen more than 90 major floods within the last 25 years, and suggest that this is due in large part to the fact that they're sinking. 'As cities continue to grow, we will see more cities expand into subsiding regions,' said lead author Leonard Ohenhen, a postdoctoral researcher at the Columbia Climate School's Lamont-Doherty Earth Observatory. 'Over time, this subsidence can produce stresses on infrastructure that will go past their safety limit,' he added. Ohenhen and his colleagues used satellite data to map sinking down to the millimeter in all US cities with populations over 600,000. They also looked at the amount of groundwater pumping in affected counties and linked it to ground sinking. Coastal cities tend to be more prone to ground sinking due to the combined effects of groundwater pumping and sea level rise. But multiple interior cities, such as Denver, Oklahoma City and Nashville, are experiencing moderate sinking. Those three are sinking roughly 0.04 to 0.08 inch per year. About one percent of land in the 28 cities is experiencing sinking that could impact critical infrastructure such as buildings, roads and rail lines. Even though that percentage seems small, these areas tend to be located in the densest parts of these cities, which contain up to 29,000 buildings. From this perspective, the most hazardous cities are San Antonio, where one in 45 buildings are at 'high risk' of damage from ground sinking, Austin, Fort Worth, and Memphis. Across the US, and in interior cities especially, ground sinking is mainly driven by groundwater pumping, the researchers concluded. When water is extracted from aquifers made up of saturated fine-grained sediments and not replenished, the pore spaces between the sediment particles can collapse. This causes the lower layers of the aquifer to condense and become compacted, and results in sinkage at the surface, according to the researchers. In Texas, this is made even worse by oil and gas drilling, they explained in their report. And there are other factors at play too. Roughly 20,000 years ago, interior North America was covered by a towering ice sheet that made the land along its edges bulge upward. That ice sheet is long gone, but some of the bulges still exist, though they are subsiding at rates of 0.04 to 0.12 inch per year. This is adding to ground sinking observed in New York City, Indianapolis, Nashville, Philadelphia, Denver, Chicago and Portland, according to the researchers. The team published their findings in the journal Nature Cities on Tuesday. A 2023 study also found that the weight of buildings in densely urbanized areas may be contributing to ground sinking. Those researchers found that New York's more than one million buildings are pressing down on the Earth so hard that they have become an important factor in the city's subsidence. New construction may be playing a role too. A more recent study found that some buildings in Miami are sinking in part due to subsurface disruptions caused by buildings going up nearby. The researchers urge cities to use their data to develop mitigation strategies for ground sinking and flood risk.
