Satellite Data Reveals Sinking Trends in Major Cities Globally
A recent study published in Nature Cities reveals significant land subsidence in major cities worldwide, with Mexico City experiencing the highest localized sinking rates of up to 217 mm per year. The study, conducted by Shengli Tao, Xie Hu, and colleagues, analyzed satellite data from 2014 to 2023, covering 465 cities in 107 countries.
Mexico City's citywide median subsidence rate was reported at 8 mm per year, while Torreón, another Mexican city, showed a rate of approximately 17 mm per year. In Indonesia, Medan and Bandung experienced subsidence rates of 33 mm and 22 mm per year, respectively. Isfahan, Iran, recorded a median rate of 11 mm per year.
In contrast, cities such as Boston, New York City, London, Beijing, and Tokyo displayed relatively stable land movement, with subsidence or uplift ranging between 0.1 to 1.9 mm per year.
The study highlights the limitations of current data, noting the focus on relative local land movement and the potential for data gaps in areas with sparse ground-station coverage. Continued monitoring is necessary to confirm long-term trends.