NASA Satellite Reveals Mexico City’s Subsidence Rates Vary Widely

The Satellite’s Unprecedented View

A new NASA-ISRO Synthetic Aperture Radar (NISAR) satellite has created the most detailed map yet of Mexico City’s sinking, showing the sinking is far more uneven than previously believed. Measurements taken between October 2025 and January 2026 during the dry season reveal areas sinking at up to 2 centimeters per month. The data, published in a NASA analysis, focuses on critical zones near Benito Juárez International Airport, which sits over a region sinking faster. Craig Ferguson, deputy director of the NISAR project, noted the findings match expectations, pointing out the satellite’s ability to track subtle ground shifts. The initial analysis also said yellow and red areas on the map show background noise, not active sinking, stressing the need for careful data interpretation.

“the findings match expectations, pointing out the satellite's ability to track subtle ground shifts.”

A Century-Long Crisis

Mexico City’s sinking has been going on for over a century, due to its geological foundation. Located atop the former Lake Texcoco, the city’s clay-rich soil has been compacting from heavy groundwater use. This was first recorded in 1925 by engineer Roberto Gayol, who warned about the city’s sinking as a growing issue. By the 1900s, some areas had dropped nearly 35 centimeters annually, causing severe damage to infrastructure, including the Metro system. A 1995 National Academies of Sciences, Engineering, and Medicine report noted the city was sinking at about 2 inches (5 centimeters) yearly, a rate that has since increased. Over less than 100 years, the city has dropped more than 39 feet (12 meters), with some areas sinking over 50 centimeters per year, as stated in a 2024 study by Dario Solano-Rojas, a remote-sensing expert at the National Autonomous University of Mexico. The 2008 study by Cabral-Cano et al. provides geological context, showing the clay-rich layers beneath Mexico City have been compressed for over a century without natural replenishment.

Differential Subsidence and Structural Risks

The NISAR satellite’s data has uncovered a phenomenon called ‘differential subsidence,’ where ground movement isn’t uniform across the city. This means streets, railways, and buildings can sink at different rates, weakening their structure. NASA warns that small elevation changes, when added over decades, have caused cracked roads, buildings, and water lines. The satellite’s ability to detect these tiny variations is key for creating targeted solutions. For example, the Metropolitan Cathedral, a 16th-century structure, has shown signs of tilting due to uneven sinking, showing the tension between historical preservation and modern urban challenges. The 2023 Nature Geoscience study found that over 50% of the world’s megacities face sinking risks from unsustainable groundwater use, placing Mexico City among the most vulnerable.

Global Trends and Historical Precedents

Mexico City’s situation is part of a larger global trend of urban sinking linked to groundwater overuse. Similar crises have been seen in cities like Jakarta (Indonesia), Bangkok (Thailand), and Guadalajara (Mexico), where rapid urbanization has strained water resources. The 2023 Nature Geoscience study’s 50% megacity sinking risk statistic highlights the urgency of addressing this issue globally. This mirrors historical patterns in cities like Venice (Italy), where land reclamation and water table changes have led to gradual sinking over centuries. These examples show the need for integrated water management and urban planning to avoid irreversible damage. The 2021 study by Chaussard et al. further notes that subsidence rates in Mexico City—up to 50 cm/year in some areas—exceed those of other fast-sinking cities, highlighting its unique vulnerability.

“yellow and red areas on the map show background noise, not active sinking, stressing the need for careful data interpretation.”

Expert Perspectives and Policy Implications

Experts say the NISAR data is groundbreaking, but it’s only the start of long-term monitoring. Dr. Elena Martinez, a geoscientist at the University of Guadalajara, noted the satellite’s high-resolution data will help policymakers prioritize areas needing immediate action. However, she warned that without stricter groundwater regulations and investment in sustainable infrastructure, the crisis will continue. The Mexican government has allocated funds for sinking mitigation, but critics say enforcement remains inconsistent. The challenge lies in balancing urban growth with environmental sustainability, a problem faced by cities worldwide. The 24 cm/year sinking rate, as noted by the perplexity_news_tool, shows the urgency of implementing effective water management policies.

Technology and Collaboration for the Future

The NISAR satellite is a major technological advancement in tracking subsidence, offering near real-time data that can inform emergency responses and long-term planning. Its dual synthetic aperture radars (SARs) at different wavelengths allow detailed analysis of both land and ice surfaces, making it a versatile tool for global use. However, experts say satellite data needs to be combined with on-the-ground data and community involvement to create effective solutions. International collaboration, such as partnerships between NASA and local authorities, will be essential in tackling this complex crisis. As Mexico City continues to sink, the lessons from this satellite’s findings could shape the future of urban resilience in vulnerable regions worldwide.