MEXICO CITY: Mexico City, one of the world's largest urban areas with around 22 million residents, is sinking at an alarming rate—nearly 25 centimeters (about 10 inches) per year. This tragic reality has been captured in recent satellite imagery from NASA's NISAR mission, which started operating earlier this year. The satellite uses advanced radar technology to monitor changes in land surface with remarkable precision, revealing that subsidence can be detected from space.

The rapid sinking is primarily due to extensive groundwater extraction for domestic and industrial use, which has led to the depletion of the city's aquifer. Built on an ancient lakebed, much of the ground below Mexico City is composed of soft volcanic rock and clay, which compresses as water is pumped out. Over the last century, the city has lost over 12 meters (around 39 feet) in elevation in certain areas, damaging vital infrastructure including subway systems and water supplies.

Recent data from NISAR indicates that some regions of Mexico City experience subsidence rates of 0.78 inches (2 centimeters) per month. Iconic structures, like the Angel of Independence monument and the main airport, are among the hardest hit. Researchers are concerned that escalating subsidence could hinder efforts to manage the city's water crisis, which is already compounded by climate change impacts.

Enrique Cabral, a geophysics researcher at the National Autonomous University of Mexico, underscored the significance of NISAR's findings, stating, “It documents the full magnitude of the problem.” The new technology will enable scientists to track subsidence more effectively and may lead to actionable insights for addressing this critical issue.

Long-term, the research aims to provide tools to mitigate the effects of subsidence and potentially help other regions facing similar challenges around the globe. As cities worldwide grapple with the increasing threats of land subsidence and climate change, advancements like NISAR could reshape how urban planners and policymakers approach these pressing issues.