The Rapid Sinking of This City Can Be Seen From Space

Mexico City is sinking by nearly 10 inches a year, according to new satellite imagery released this week by NASA, making it one of the world's fastest-subsiding metropolises. One of the world's most sprawling and populated urban areas, at 3,000 square miles and some 22 million people, the Mexican capital and surrounding cities were built atop an ancient lake bed, per the AP. Many downtown streets were once canals, a tradition that continues in the rural fringes. Extensive groundwater pumping and urban development have dramatically shrunk the aquifer, meaning that Mexico City has been sinking for more than a century, leaving many monuments and older buildings—like the Metropolitan Cathedral, where construction began in 1573—visibly tilted to the side.

The contracting aquifer has also contributed to a chronic water crisis that's only expected to worsen. "It damages part of the critical infrastructure of Mexico City, such as the subway, the drainage system, the water, the potable water system, housing, and streets," said researcher Enrique Cabral-Cano, of the National Autonomous University of Mexico. "It's a very big problem." In some parts it's happening at an average rate of 0.78 inches a month, according to NASA's newly released report, such as at the main airport and the iconic monument commonly known as the Angel of Independence. Overall, that means a yearly subsidence rate of about 9.5 inches. Over the course of less than a century, the drop has been more than 39 feet, according to Cabral-Cano.

"We have one of the fastest velocities of land subsidence in the whole world," he said. The NASA estimates are based on measurements taken between October 2025 and January of this year by a powerful satellite known as NISAR, which can track real-time changes on the Earth's surface and is a joint initiative between NASA and the Indian Space Research Organization. In time, the team hopes to be able to zoom in even more on specific areas and someday get measurements on a building-by-building basis. More broadly, researchers hope to apply the technology around the world to track things like natural disasters, changes in fault lines, the effects of climate change in regions like Antarctica, and more.

For Mexico City, the technology amounts to a big advance in studying the subsidence issue and mitigating its worst effects, according to Cabral-Cano. For decades the government has largely ignored the problem, other than stabilizing foundations under monuments like the cathedral. But following recent flare-ups of the water crisis, Cabral-Cano said, officials have begun to fund more research. Imagery from the NISAR satellite and the data that comes with it will be key for scientists and officials as they plan on how to address the problem. "To do long-term mitigation of the situation," Cabral said, "the first step is to just understand."