Mexico City is sinking. In fact, it's one of the fastest-sinking capital cities in the world, and the rate at which it's sinking has now been confirmed by a NASA satellite orbiting Earth.
The NISAR (NASA-ISRO Synthetic Aperture Radar) satellite is one of the most powerful radar systems ever launched into space, according to NASA.
It's been able to capture images of Mexico City that reveal just how much the Mexican Capital is subsiding, but also which areas of the city are sinking fastest.
More Earth from space
A sinking city
Mexico City sits on top of a layer of saturated rock known as an aquifer.
In the 1920s it was confirmed that the capital, which is home to over 22 million people, is subsiding as a result of the water-logged ground on which it was built.
There are reports of buildings, monuments and other infrastructure tilting and cracking, and sinkholes are a relatively regular occurrence, compared to other cities around the world.
A key example is the Angel of Independence monument in Mexico City, which has needed steps added to it over the years to counteract the effects of subsidence.
The city's sinking has been exacerbated over the past century or so, with groundwater pumping and extensive urban development adding to the problem.
NASA says that, by the 1990s and 2000s, parts of Mexico City were sinking by around 35cm (14 inches) per year, even causing damage to the Metro, the city's underground transport network.
An eye in the sky
The NISAR (NASA-ISRO Synthetic Aperture Radar) satellite is an Earth-orbiting mission that tracks real-time changes across our planet.
Because it tracks data beyond optical light, it can record changes occurring across Earth through clouds, and even at nighttime.
Launched in July 2025, the joint NASA and Indian Space Research Organisation (ISRO) satellite tracks phenomena such as land sinking and rising, glaciers sliding and croplands growing.
NISAR studied Mexico City between October 2025 and January 2026, the city's dry season.
It found parts of the city are subsiding by more than 2cm (0.5 inches) a month, and these are shown in dark blue on the map pictured here.
NASA says yellow and red areas are likely residual noise signals, but these are expected to clear up as NISAR continues to collect data.
"Images like this confirm that NISAR’s measurements align with expectations," says Craig Ferguson, deputy project manager at NASA Headquarters in Washington.
"NISAR’s long wavelength L-band radar will make it possible to detect and track land subsidence in more challenging and densely vegetated regions such as coastal communities where they may have the compounding effects of both land subsidence and sea level rise."
"Mexico City is a well-known hot spot when it comes to subsidence, and images like this are just the beginning for NISAR," says David Bekaert, a project manager at the Flemish Institute for Technological Research and a member of the NISAR science team.
"We’re going to see an influx of new discoveries from all over the world, given the unique sensing capabilities of NISAR and its consistent global coverage."
