Wednesday, July 21, 2010

Explaining the giant holes in Guatemala

from forgetomori:

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They are an amazing sight: even though the initial size figures were eventually corrected to a more comprehensible 66 feet diameter crater, 100 feet deep, those are still impressive and quite regular holes. The one in the image above engulfed a factory in the end of June at Zona 2, Guatemala, while a similar event happened in 2007 a few miles away, Zona 6. Below, an image of the 2007 hole:

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While people were puzzled and many joked about these giant holes in the ground, the event in 2007 resulted in two casualties and the one a month ago in one death. Taking this seriously, we have to explain that these features are not mysterious nor have anything to do with “UFO tunnels”. Both features were ultimately the result of intense storms – and it’s an interesting coincidence that the new hole opened after tropical storm Agatha, since Agartha is the legendary city inside the hollow Earth.

These features do not lead to the center of Earth, however, at their bottom a hundred feet down what one finds is quite simply a sewage water collecting system. The infographic below, from Nuestro Diario (June 30th, p.5), illustrates how exactly below the opened hole a water collector tunnel around 10 feet in diameter goes through.

craterzona2

A few days ago a team of geologists also explored the bottom of the Zona 2 hole, you can find the whole Picasa set of photos here. All the soil in the giant hole didn’t disappear magically, it was simply washed away with the water and on to the sewage system. So much so that the sole victim’s body in the Zona 2 hole, Edwin Roberto Velásquez Salazar, was found days later in Las Vacas river, where the water from the collector system ends up.

Not only at the bottom of these giant holes one finds tunnels of the water collecting system: more importantly, perhaps, is that both of these holes were originally vertical shafts, that is, there were already originally vertical holes there, even though they were obviously not that large. Unfortunately many water draining shafts and tunnels were built in the 1950s and some were not properly recorded, and as the city grew some buildings were built over some shafts. That seems to be the case here.

Local geologists suggest then that the heavy water stream from the storm must have damaged the underground collecting tunnels, a problem aggravated by the fact that there was a difference in the level of tunnels. The graphic below (click to enlarge, from Diario de Centroamérica) illustrates, above, the proposed evolution of the holes in the first (above) and second holes.

guatemalagiantholes

Add to that that the soil in the city is particularly fragile, basically pumice fill – ash flows made up of loose, gravel-like particles deposited during ancient volcanic eruptions, and there’s no mystery here.

Days after the recent hole, called by many a giant sinkhole, geologist Sam Bonis, who was part of the team that investigated the 2007 case, correctly pointed out that it wasn’t in fact a sinkhole. As he told Discovery News (and National Geographic), "Sure, it looks a lot like a sinkhole. And a whale looks a lot like a fish, but calling it one would be very misleading.

According to Bonis, the hole was rather a “piping feature”, and the further info, photos and graphics here may help understand the giant holes in Guatemala.

Colectores-for-dummies

Graphic: Nuestro Diario

[Almost all the info for this post comes from the blog “Ciudad Nueva zona 2 Guatemala”, with updated and detailed information on the events. It was suggested to me by friend José Ildefonso, who also provided me with most of the other information on the case]


2 comments:

  1. Great post yo.. I was anchored on a small 30ft sail boat in Nicarugua when i found out this happened. Shit was crazy down there, we sailed out of Mexico and into Central America right when those storm systems blew through. It was wild, everything was chaos, I was right off the coast of Guatemala entering into El Salvador when this particular event happened. We sailed down the coast of Mexico from California for 5 months prior to entering Central America, it was wild like I said, we did hit some crazy weather on our way down Mexico, but once we got into Central America shit just went into overdrive. We where one of the few small crafts in the ocean at this time and it was touch and go, life and death it seemed like every other hour.. FOR REAL! I was like "COME ON ALREADY", storm after storm; thank god for sea anchors. We even got stuck in the last port in Mexico for two weeks because our boat got thrashed while trying to exit Mexico for the first time, the first storm was so bad that in literally pushed us backwards 9 miles. Both engines got worked so hard that they shit the bed and we were trapped in the 3rd world port of Puerto Madero Mexico for two freaking weeks.. Nothing better then being trapped on a small fiberglass boat for two weeks, out in the blazing sun with the water so nasty that there was constant human feces floating by.
    Also, the one thing people dont seem to bring up is the fact that the largest volcano in Guatemala was spewing ash all over the city and country around the time this sink hole opened up. Then it rained, the ash became rivers of mud and so on. WHAT A FREAKING MESS!!
    All in all I am alive and well, back home in NYC for the first time in 15 years and I could not be happier... My heart goes out to all of Mexico and Central America for this El Nino year has been very hard for them..
    But, I must say it was all one hell of a rush for me... I would NEVER wish for that to happen again, but looking back at it all it was wild yo!
    WORD!

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