I have been thinking about this "Mexico Falls" lately. It could have many interpretations, but what came to my mind was that the Spaniards built Mexico City over Tenochtitlan, that was built over a lake :P, this not only causes stronger seismic activity, becasue soft or wet sediment tends to amplify seismic waves and create more shaking, but as the water of the lake has been almost depleted for consumption for a long time, the city is loosing support and it's actually sinking.
A 40's newspaper article:
trove.nla.gov.au/ndp/del/article/42632014
And not only the depleted lake factor, there's also this:
One of the big risks of the sinking city, could be a strong enough earthquake that could cause mayor parts of the city to collapse.
A 40's newspaper article:
trove.nla.gov.au/ndp/del/article/42632014
How fast is the ground sinking in Mexico City and what can be done about it?
geo-mexico.com/?p=6229
A recent report from researchers at the National Autonomous University of Mexico (UNAM) and the Metropolitan Autonomous University (UAM) confirms that the height of the water table below Mexico City is dropping by about one meter a year, as more water is pumped out of the aquifer than the natural replenishment rate from rainfall.
Mexico's capital is a sinking metropolis
azcentral.com/news/articles/2010/04/08/20100408mexico-city-sinking-flooding-crisis.html#ixzz31kct9NwC
Deep underground, tunneling crews are in a race against time as they try to save the world's third-largest metropolis from catastrophe. Above them, the Mexican capital is sinking into the earth at a record rate, tilting the city's sewage tunnels so they are actually running backward. Crews are rushing to build a 37-mile drainage tunnel to save much of the city from future floods.
Unbalanced in the Sinking City
flightnetwork.com/blog/unbalanced-in-the-sinking-city/
Mexico City shouldn’t even be here. It should really be some pretty little island town surrounded by water, connected to the rest of Mexico by bridges, with volcanic mountains gleaming through the clear air in the distance. In the Museum of Anthropology there’s a giant mural depicting what life was like when the Aztecs ruled in the early 1500s, with water covering most of the area where buildings and streets now sit.
And not only the depleted lake factor, there's also this:
Deep caverns and old mine shafts are giving Mexico City a sinking feeling
globalpost.com/dispatch/news/regions/americas/mexico/140320/cavern-mexico-city-sinkhole
A collapsing mine shaft forced the demolition of a dozen houses and threatened to swallow more than 300 others in one neighborhood in 2007. Another sinkhole nearby consumed two more houses in 2011. Still another that suddenly gaped on a street last summer has spared homes so far.
“There was nothing here when I first arrived. Just fields and mine shafts,” says Orozco, who moved here with her family from the countryside in the 1960s. “If there are caverns beneath all of this, how can we not have collapses?”
City crews have filled in about 900 mines with rock and concrete in recent years, Alaniz says. The work continues as new shafts are discovered, usually when cracks appear in the walls of an affected building or a hole suddenly yawns in a street or yard.
The sinkholes are a constant worry, Orozco and other residents say. Earthquakes pose another one entirely.
Mexico City is sinking! More gigantic earthcracks in Valley of Mexico
thewatchers.adorraeli.com/2011/07/22/mexico-city-is-sinking-more-gigantic-earthcracks-in-valley-of-mexico/
Excelsior was reporting about the crack which appeared on 13 July in Santa Maria Huejoculco in Chalco, State Mexico. The earthcrack has now reached 1500 meters long. Just after survey work was detected in Santa Maria Huejoculco yet another gap of about four km which reaches La Candelaria Tlapala, was found in the community of Miraflores, in Chalco. This event began back 2009 in a small area of this region but since that time, it has grown and opened to devour everything around it. The continued sinking of some parts of Mexico City in response to the over-extraction of water from underground aquifers, and consequent shrinking of the subsoil, has resulted in dozens of cracks in recent years.
One of the big risks of the sinking city, could be a strong enough earthquake that could cause mayor parts of the city to collapse.