Mexico City’s sinking crisis mapped by next-generation satellite

Mexico City’s long-documented subsidence problem is receiving renewed attention after the NASA-ISRO Synthetic Aperture Radar (NISAR) mission mapped areas of the metropolitan region sinking by more than 20 mm per month. The findings, released by NASA/JPL in April 2026, are based on preliminary NISAR measurements collected between October 2025 and January 2026, and show how space-based radar can support geotechnical monitoring across dense urban regions.

Built atop the soft sediments of an ancient lakebed, Mexico City has faced progressive settlement for more than a century due largely to groundwater extraction, aquifer depletion, and the weight of urban development. NASA notes that the issue was first documented by an engineer in 1925, while by the 1990s and 2000s some parts of the metropolitan area were sinking by around 350 mm annually. NISAR’s recent dry-season analysis confirms that severe settlement remains active, particularly in areas underlain by highly compressible lacustrine clays.

Unlike conventional optical monitoring, NISAR’s L-band synthetic aperture radar can collect deformation data day or night and is not limited by cloud cover or vegetation. This capability is significant for cities where subsidence affects transport systems, utilities, foundations, and flood resilience. Mexico City’s Metro system, roads, water lines, buildings, and historic structures have all experienced damage or distortion over decades, while the Angel of Independence monument has famously required 14 additional steps at its base since its construction in 1910 as the surrounding ground gradually lowered.

NISAR is more than a mapping tool. Its repeated radar observations can help engineers and planners identify settlement hotspots, evaluate infrastructure exposure, and prioritize areas for further field investigation. According to NASA/JPL, the satellite is designed to monitor Earth’s land and ice surfaces twice every 12 days, providing consistent coverage that could improve monitoring in soft-ground megacities, coastal zones affected by sea-level rise, and regions vulnerable to groundwater-induced consolidation.

The broader engineering significance lies in the potential for earlier detection. Subsidence is often addressed after visible damage appears, but high-resolution radar data can support more proactive urban resilience planning. Mexico City is a clear example of how long-term groundwater extraction and compressible soils can combine to create persistent infrastructure risk. As NISAR continues collecting data globally, similar hidden ground-deformation hazards may become easier to detect, monitor, and manage.