Serious question. How could the subsurface geology result in something like this?
[Crap. Closed the link with the pictures and stuff.]
Serious question. How could the subsurface geology result in something like this?
[Crap. Closed the link with the pictures and stuff.]
OK. We’ve 2 Wikipedia links: One to an explanation of Karst topography (which doesn’t mention Guatamela) and another on Sinkhole Mechanisms. What does Discovery News have to say?
He explained this to the government when it happened in 2007 & said it could happen again. (No mention of Karst topography.)
I’m not a geologist but am just filling time until they can distract themselves from That Thing In The Gulf…
IANAG but I think the notable thing about this particular sinkhole is that it had a cap of concrete and asphalt and whatever else is underpinning the neighborhood and instead of slumping the cap just cracked and dropped down once the hole got wide enough and left that bizarre-looking sharp edge.
Put a pool in the bottom, and you’d have a nice looking cenote.
The entire Yucatan peninsula is Karst topography, with an abundance of cenotes. I don’t know for sure if the limestone extends as far south as Guatemala City, but I wouldn’t b surprised.
Bridget Burke’s linke gives a good description of the local geology:
From one of the articles I read, it sounds like the pumice fill under the factory may have been eaten away by water from a leaking storm drain or something, until the cap gave way?
A couple years ago I saw a documentary on Discovery that asserted that the cenotes in the Yucatan are a remnant of shock waves from the meteor that killed the dinosaurs. I’m not sure how seriously to take Discovery - is there any truth to that?
I understand that the width of modern railroad tracks was determined by Roman chariot ruts,
Yes and no.
There is some pretty good evidence that the impact caused significant/distinct fractures in the already existing limestone. Then like all limestone cave developement, water eroded/enlarge those particular fractures to become the cenotes/caves in the area.
Caves would have formed in that area anyway in random/different fractures.
Its more complicated than that, but Discovery wasnt pulling your leg at least.
This is also my guess. There was another such “sinkhole” in Guatemala in 2007. IIRC it was traced to a leaking sanitary sewer.
I have come several of these on a smaller scale over the years; usually a leaking pipe (water, sewer, storm drain) erodes dirt particles over time, creating a void beneath the ground, and leaving a ‘crust’ overhead. Eventually the ‘crust’ gets too thin to stand and it all collapses.
Band name! Sounds very Lovecraftian too…
So, back off ten or twelve thousand miles, and look at the Gulf of Mexico.
It’s all one great big sinkhole.
It sits on the oldest crustal bedrock on the planet, which is cooled and crystallized more thoroughly than the bedrock anywhere else on earth. So, it transmits shocks, breaks into faults, and otherwise structurally fails more readily than the solid earth anywhere. And when it does, bits of it sink. The whole thing is sinking a few centimeters a century.
It also hosts underground aquifers from two continents, which flow through the porous strata, slowly dissolving them, and undermining them, and failing, here and there. A whole lot of water is moving through the basin that surrounds the Gulf of Mexico. Water is a pretty good solvent.
Tris
Almost a universal solvent.
But, things don’t have to be dissolved to be moved by underground water; all the water has to do is flow fast enough to overcome the cohesiveness of the soil and the weight of the particle. (The velocity at which a particle is initially moved is the tumbling velocity).
Not original to me.
“That Thing in the Gulf” is a painting by Myla Bertinot. She shows at Harris Gallery; click on her name to see her stuff. That painting isn’t available online–it’s a skyscape depicting the swirly menace you see when there’s a killer storm Out There–deciding where it’s going to go. I saw it pre-Katrina; she’s a New Orleans artist & it shows in her later work.
By the way–anybody who feels that “modern” art is just a bunch of trendy crap ought to check out the mostly representational artists the gallery represents. I’m able to appreciate some of the weird shit out there, but the art scene includes a wide variety of styles. And Harris Gallery has a full bar at openings–not the warm keg of Shiner Bock you’ll find at the more avant-garde venues…
I thought the phrase represented the current situation quite well.
It sounds like you are saying that the hole was already there, and city engineers patched it over.
To my understanding, the bedrock above the chasm was there to begin with, and that is what dropped, taking the concrete and asphalt (and houses) with it.
Can someone better informed clarify this?
The best description of the topography comes from this article I linked earlier.
My long ago Mesoamerican Archaeology course made a distinction between the Lowland & Highland Maya. The Lowland Maya lived in the flat limestone, cenote containing topography; the Highland Maya lived among volcanic mountains. The major Highland site is Kaminaljuyu–which is mostly underneath today’s Guatemala City. The Lowland Maya ruins are more spectacular (& less covered by a modern city) but the Highland area is earlier & very important.
Jesus, that looks CG, like it’s some Onion news story.
No, I’m just saying that the bizarre appearance of the sinkhole is because it’s in an urban area and rather than slumping in, the surface broke off cleanly and dropped in, leaving the sharp ‘clean’ edges.