Mexico City, one of the world’s largest urban areas with some 22 million residents, is built atop the drained bed of a former lake. For over a century, intensive pumping of groundwater from the aquifer beneath the city has caused the ground to collapse, a process now documented in unprecedented detail by NASA’s NISAR satellite.
The satellite, a joint mission between NASA and the Indian Space Research Organisation, measured subsidence between October 2025 and January 2026, finding that the metropolitan area is sinking at an average rate of nearly 9.5 inches per year, or roughly 2 centimeters per month in certain hotspots, according to a NASA report released this week. At the city’s main airport and at the iconic Angel of Independence monument, the ground is dropping by 0.78 inches each month.
Enrique Cabral, a geophysicist at the National Autonomous University of Mexico, said the subsidence damages critical infrastructure including the metro, the drainage system, the drinking water supply, housing, and streets. The city has sunk more than 12 meters (39 feet) over the past century, he added, leaving landmarks like the Metropolitan Cathedral — construction of which began in 1573 — visibly tilted.
The intensive pumping that compresses the aquifer has also driven a chronic water shortage, with forecasts that the crisis will worsen. For decades, the government largely ignored the problem except for shoring up foundations under monuments like the cathedral. But after recent worsening of the water shortage, Cabral said, authorities have begun to fund more research.
Paul Rosen, a NISAR scientist, said the satellite’s radar data provide a detailed picture of what is happening across the city and beneath its surface, capturing the full magnitude of the problem. The technology could eventually zoom in enough to monitor subsidence on a building-by-building basis, he said. Researchers also hope to apply the satellite’s real-time surface-change detection globally, to track natural disasters, fault-line movements, and climate-change impacts.
For Mexico City, the NISAR images represent a major advance in understanding the subsidence crisis and planning for its long-term mitigation, Cabral said.
“Para hacer una mitigación de largo plazo de la situación, el primer paso es simplemente entender,” Cabral said. (“To carry out long-term mitigation, the first step is simply to understand.”)