NASA Satellite Reveals Rapid Sinking of Mexico City

The Invisible Crisis: How Sinking Cities are Redefining Urban Survival

For millions of people, the ground beneath their feet is not as solid as it seems. In Mexico City, more than 20 million people live on land that is slowly descending into an ancient lakebed. While the phenomenon of land subsidence is not new, the way we monitor and combat it is undergoing a radical technological shift.

The challenge has always been visibility. For decades, researchers relied on ground-level surveys or satellites that provided data only once a year. This created a dangerous lag between the movement of the earth and the city’s response. Now, the arrival of the NISAR satellite—a joint venture between NASA and the Indian Space Research Organisation (ISRO)—is changing the game.

The NISAR Revolution: From Annual Snapshots to Real-Time Tracking

Unlike its predecessors, NISAR utilizes two radar systems with different wavelengths. This allows the satellite to record changes in the earth’s surface every 12 days. For urban planners and geologists, this shift from annual to near real-time data is a breakthrough in disaster prevention.

“Everything this allows us to do is create time series or snapshots of how the earth’s surface is moving over time.” David Becquart, NISAR mission scientist

This high-frequency monitoring reveals a stark reality: some parts of Mexico City are sinking by more than half an inch every month. When these gradual shifts accumulate, the result is catastrophic structural failure. The city has seen the destruction of roads, buildings, and pipelines, creating a landscape where the architecture is literally fighting the earth.

Why Cities Sink: The High Cost of Urban Thirst

The primary culprit behind this descent is not a natural geological shift, but human necessity. Decades of pumping water from the ancient aquifer beneath the city have left the soil hollow. As the water is removed, the remaining clay compresses and hardens.

This process is akin to squeezing a wet sponge; once the water is gone, the material collapses in on itself. According to research published by the American Geophysical Union, this compaction is permanent. Once the land sinks, it does not bounce back.

A Century of Descent

The scale of the problem is best understood through the timeline of its acceleration. Data from the National Academies of Sciences, Engineering, and Medicine indicates that by the conclude of the 19th century, the city was sinking at approximately 5 centimeters per year.

By the 1950s, that rate skyrocketed to 45 centimeters per year. The long-term impact is staggering: while some areas have lost 9 meters of elevation over the last century, the most severely affected zones have plunged by up to 42 meters.

“The houses built on volcanic rock are stable, but the houses located between the rock and the lake plain are already destroyed, most of them,” Dora Carreón-Freire, researcher

Beyond Mexico City: A Global Pattern of Risk

Mexico City is a cautionary tale, but it is not an isolated case. The technology being deployed by NASA is intended for a much broader application. Coastal zones worldwide, where a significant portion of the human population resides, face similar threats from a combination of groundwater extraction and rising sea levels.

Cities like Jakarta, Bangkok, and Venice are grappling with similar subsidence issues. The ability to map earth movement in near real-time allows these cities to move from reactive repairs to predictive engineering. By identifying which neighborhoods are sinking fastest, governments can prioritize infrastructure reinforcement before a road collapses or a pipeline bursts.

The integration of satellite data with urban planning is no longer a luxury—it is a survival strategy. As we seem toward the future of sustainable urban development, the focus is shifting toward “living with the land” rather than trying to force it to remain static.

Frequently Asked Questions

What is land subsidence?
Land subsidence is the gradual settling or sudden sinking of the Earth’s surface due to the removal of subsurface support, most commonly caused by the extraction of groundwater or oil.

How does the NISAR satellite help?
NISAR uses dual-frequency radar to monitor surface changes every 12 days, providing near real-time data that allows scientists to see exactly where and how prompt the ground is moving.

Can sinking land be reversed?
In most cases, particularly with clay compaction, the sinking is permanent. Though, the rate of descent can be slowed or stopped by reducing groundwater extraction and implementing aquifer recharge programs.