Mexico City is sinking so quickly, it can be seen from space

MEXICO CITY — Mexico City is sinking by nearly 10 inches (about 25 centimeters) a year, according to new satellite imagery released this week by NASA, making it one of the world’s fastest-subsiding metropolises. One of the world’s most sprawling and populated urban areas, at 3,000 square miles (about 7,800 square kilometers) and some 22 million people, the Mexican capital and surrounding cities were built atop an ancient lake bed. Many downtown streets were once canals, a tradition that continues in the rural fringes. Extensive groundwater pumping and urban development have dramatically shrunk the aquifer, meaning that Mexico City has been sinking for more than a century, leaving many monuments and older buildings - like the Metropolitan Cathedral, where construction began in 1573 - visibly tilted to the side. The contracting aquifer has also contributed to a chronic water crisis that is only expected to worsen. “It damages part of the critical infrastructure of Mexico City, such as the subway, the drainage system, the water, the potable water system, housing and streets,” said Enrique Cabral, a researcher studying geophysics at the National Autonomous University of Mexico. “It’s a very big problem.” Mexico City is sinking so fast that the subsidence