Miami.- According to a study by Columbia Climate School, ” cities bigger of USA They are sinking “, in different degrees and by different factors: the extraction of groundwater, the geological processes and the weight of the buildings.
In 25 of the 28 most populated cities in the country, two thirds or more of its surface “they are sinking,” said the study.
Research published this week in the magazine Nature Cities It also indicates: “In total, about 34 million people live in affected areas.” For the study, satellite data were used to examine the vertical movements of the Earth.
Houston, In Texas, it is the city that sinks faster. Two other locations in this southern state, Fort Worth and Dallas, are not far behind. New York areas, Las Vegas, Washington DC (La Capital) and San Francisco also stand out.
The researchers concluded that “the extraction of groundwater for human use was the cause of 80% of the general sinking.” In Texas, “the problem is aggravated by oil and gas pumping.”
Cities in different rhythms
Leonard Ohenhen, a researcher at the Lamont-Doherty Earth Observatory of Columbia Climate School and the main author of the study, said: “As the cities continue to grow, we will see that more cities expand towards regions that sink.”
The study finds that some cities sink at different rhythms in different places, or lose height in some and win it in others, “which could introduce tensions” and “affect buildings and other infrastructure.”
According to researchers, the continuous growth of the population and the use of water, along with droughts, “the situation in the future will probably worsen.
In some areas, natural forces contribute to the phenomenon. The weight of the ice layer that occupied a large part of North America until about 20,000 years ago caused the land to stun at the edges and some of these protuberances decrease a few millimeters every year. In addition, the weight of the buildings can also be taking its toll.
