Mexico City is sinking so fast that the subsidence can be spotted from space

Key Points:

• NASA satellite imagery reveals that Mexico City is sinking at a rate of nearly 25 centimeters (10 inches) per year, making it one of the fastest-subsiding major cities globally due to groundwater depletion and urban development.
• The city's foundation on an ancient lake bed, combined with extensive groundwater pumping, has caused significant subsidence over the past century, damaging infrastructure such as the subway, drainage, water systems, and historic buildings like the Metropolitan Cathedral.
• Measurements from NASA's NISAR satellite, a joint project with the Indian Space Research Organization, provide real-time tracking of land subsidence, enabling detailed documentation of changes and potential future monitoring at a building level.
• Researchers aim to use this technology worldwide to monitor natural disasters, fault line shifts, and climate change effects, while also enhancing alert systems for events like volcanic eruptions.
• Mexican authorities, previously slow to address the issue, have recently increased funding for research, with NISAR data expected to play a crucial role in understanding and mitigating Mexico City's ongoing sinking problem.