Mexico City Sinking: Metropolis Could Plunge 65 Feet in 150 Years Due to Subsidence

Mexico City has been sinking. According to a report, the metropolis has probably dropped by 65 feet in the next century and a half.

Mexico City Sinking

The topography of Mexico City is condensing, and some areas of the metropolis are currently eroding 1.5 feet annually. The city was seriously sinking due to subsidence. Dario Solan-Rojas and geophysicist Enrique Cabral-Cano met and discussed the confusing layout of the structures in the city. The two academics and their colleagues' latest simulation indicates that the city is sinking up to 20 inches annually in some areas. They estimate that areas could decrease by as much as 65 feet over the next 150 years. Areas close to Mexico City's center might submerge 100 feet. The bending and tilting that Dario Solano-Rojas observed was just the beginning of a slow-motion crisis for the 9.2 million people residing in the world's fastest-sinking city.

The flawed foundation of Mexico City is the root of the issue. Tenochtitlan, the Aztec capital, was constructed on an island within Lake Texcoco in a mountainside basin.

The lake was drained, and structures were being built on top of it when the Spanish invaded, devastated Tenochtitlan, and slaughtered its inhabitants. The sprawling metropolis now known as Mexico City continued until the lake vanished.

And that started the physical alterations that started the city's sinking. The clay particles that made up the lake silt beneath Mexico City were arranged randomly when wet. Consider the effect of randomly arranging plates in a sink; a lot of liquid will flow between them.

However, when the water is gone-as, Mexico City's planners did when they initially drained the lake and as the city has since done by tapping the ground as an aquifer-those particles reorganize themselves to stack neatly, like plates stored in a cabinet. The silt compacts as the distance between the particles decreases.

Alternatively, picture applying a clay face mask. The mask starts to feel tighter against your skin as it dries. According to Solano-Rojas, "it's losing water and it's losing volume."

The officials first identified the subsidence issue in the late 1800s. They discovered it when observing sinking structures in Mexico City and collecting measurements.

As a result, Solano-Rojas and Cabral-Cano were able to combine this useful historical information with satellite readings from the previous 25 years. These orbiters monitor the city's surface heights in great detail, with a resolution of 100 feet, by beaming radar pulses at the ground.

While their new modeling reveals that subsidence rates would differ from block to block, the researchers used this data to estimate that Mexico City's silt will take another 150 years to completely compact. The clay in a particular area sinks more quickly the thicker it is. Because they are situated on rock rather than sediment, other regions, especially those outside the city, may not sink.

ALSO READ : 7.8 Magnitude Turkey-Syria Earthquake Not Common in Strike-Slip Fault; Strong Aftershocks Explained

What Is Subsidence?

Subsidence is a geological process often occurring when too much water is extracted from the earth, causing the land above to compact. In simpler words, it's the sinking of the ground due to the movement of underground materials due to the removal of water, oil, natural gas, or mineral resources.

The condition can also be caused by natural events like earthquakes, soil compaction, glacial isostatic adjustment, erosion, sinkhole formation, and the addition of water to fine soils brought by wind, a natural process called loess deposits.

Mexico is situated near a zone of subduction, where the North American continental plate is being pushed beneath the Cocos oceanic plate. Strong earthquakes can be quite destructive because of the friction between the crusts. Since Mexico City is constructed on soft ground, the effects of earthquakes brought on by these tectonic plates are amplified.