New satellite imagery released by NASA has revealed that Mexico City is sinking by nearly 10 inches (approximately 25 centimeters) each year, making it one of the fastest-subsiding metropolitan areas in the world. The data, collected between October 2025 and January 2026 by the NISAR satellite—a joint project between NASA and the Indian Space Research Organisation—shows that the subsidence is so rapid it can be detected from space.
An Ancient Lake Bed Under Pressure
Mexico City and its surrounding urban sprawl, covering about 3,000 square miles (7,800 square kilometers) and home to some 22 million people, were built atop an ancient lake bed. Many downtown streets were originally canals, a tradition that still persists in rural outskirts. Extensive groundwater pumping and relentless urban development have drastically depleted the aquifer beneath the city, causing the ground to sink for over a century. This has left numerous monuments and older buildings, such as the Metropolitan Cathedral (construction began in 1573), visibly tilted.
Infrastructure at Risk
The contracting aquifer is not only causing subsidence but also exacerbating a chronic water crisis that is expected to worsen. Enrique Cabral, a geophysics researcher at the National Autonomous University of Mexico, highlighted the severity: “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. It’s a very big problem.” In some areas, including the main airport and the iconic Angel of Independence monument, the ground is sinking at an average rate of 0.78 inches (2 centimeters) per month.
Overall, the yearly subsidence rate is about 9.5 inches (24 centimeters). Over less than a century, the drop has exceeded 39 feet (12 meters), according to Cabral. “We have one of the fastest velocities of land subsidence in the whole world,” he said.
NISAR: A New Eye in the Sky
The NASA estimates are based on measurements from the NISAR satellite, which can track real-time changes on Earth’s surface. NISAR scientist Paul Rosen explained that the project is “telling us something about what’s actually happening below the surface.” By capturing detailed imagery of the Earth, it provides “documentation of all of these changes within a city” and reveals “the full magnitude of the problem.” The team aims to eventually zoom in on specific areas and obtain measurements on a building-by-building basis.
Broader Applications
Beyond Mexico City, researchers hope to apply this technology globally to monitor natural disasters, fault line changes, climate change effects in Antarctica, and more. Rosen noted it could enhance alert systems, allowing scientists to warn governments about evacuations needed for volcanic eruptions, for example.
A Step Toward Mitigation
For Mexico City, the NISAR technology represents a major advance in studying and mitigating subsidence. For decades, the government largely ignored the problem, except for stabilizing foundations under monuments like the cathedral. However, recent water crises have prompted officials to fund more research. Cabral emphasized that imagery from NISAR and its accompanying data will be crucial for scientists and officials planning long-term solutions. “To do long-term mitigation of the situation,” he said, “the first step is to just understand.”
