Mexico City Sinking At Rate Of Up To 2 Cm/month, As Revealed By New NASA Orbital Radar System

[hatrack]

Walking into Mexico City’s sprawling central Zócalo is a dizzying experience. At one end of the plaza, the capital’s cathedral, with its soaring spires, slumps in one direction. An attached church, known as the Metropolitan Sanctuary, tilts in the other. The nearby National Palace also seems off-kilter.The teetering of many of the capital’s historic buildings is the most visible sign of a phenomenon that has been ongoing for more than a century: Mexico City is sinking at an alarming rate.

Now, the metropolis’s descent is being tracked in real time thanks to one of the most powerful radar systems ever launched into space. Known as Nisar, the satellite can detect minute changes in Earth’s surface, even through thick vegetation or cloud cover.“Nisar takes radar imaging observations of Earth to the next level,” said Marin Govorčin, a scientist at Nasa’s jet propulsion laboratory. “Nisar will see any change big or small that happens on Earth from week to week. No other imaging mission can claim this.” Though not the first time that Mexico City’s sinking has been observed from space, the Nisar mission has provided a greater sense of how far the sinking spreads and how it changes across different types of land than any other space-based sensor. It has also been able to penetrate areas on the outskirts of the city that were previously challenging to study because of the complex terrain.The implications of the imagery extend far beyond the Mexican capital.

EDIT

The Nisar system, a joint initiative between Nasa and the Indian Space Research Organisation, found that some areas of Mexico City, including at the city’s main airport, were sinking by more than 2cm a month, one of the fastest subsidence rates in the world. Among the clearest examples of this rapid descent is the Angel of Independence statue on the city’s main Paseo de la Reforma avenue. Completed in 1910 to commemorate 100 years of Mexican independence, the 36-metre monument has had 14 steps added to its base as the land around it has gradually sunk.

But the impact of Mexico City’s subsidence can be seen across the metropolis of about 22 million people, from tilting buildings to warping roads and damages to the underground metro system.Efraín Ovando Shelley, another engineer at Unam, said: “It affects the entire urban infrastructure of the city: the streets, the pipes for water distribution, the water supply, the drainage pipes.” First documented in 1925, the city’s sinking is a result of centuries of exploitation of the groundwater. Because Mexico City and its surrounds were built on an ancient lake bed, the soil beneath the city is extremely soft. When water is pumped out of the aquifer below, this clay-like earth compacts, resulting in a city that is quietly sinking.

EDIT

https://www.theguardian.com/world/2026/may/07/mexico-city-sinking-subsidence-2cm-a-month-nasa-nisar

[harumph]

1. 2 cm/mo is astonishingly bad.

" First documented in 1925, the city’s sinking is a result of centuries of exploitation of the groundwater. "

I guess that happens when you don't manage resources properly and allow unconstrained growth. In the US we've been relatively lucky - but there was a Tulane prof. yesterday speaking on KERA about New Orleans, rising waters and its inevitable relocation. He opined that the time was now to talk about relocation further inland. It's a sad commentary when people are only brought over to the side
of environmentalism when something catastrophic occurs in front of their eyes - meaning in the space of a few decades. On the slightly optimistic side, maybe the rate of subsidence will slow.