Another media scaremongering campaign?

Or the end of the world?

Discuss.

Also there is The Simpons episode where Homer leaves the faucet dripping and it slowly causes a sinkhole in the middle of Springfield. It swallows up Marge while she is driving. The story leads her to bye a new car.




Edited by leftrightout: 28/3/2013 03:28:52 PM

Media scare mongering. It's like 10 years ago how being struck by lightning got an assload of coverage.

I don't think it's scaremongering, it just happens there has been a few of them happen recently so it catches peoples attention.
Some dude in Florida got swallowed up, never to be seen again, then there was two in China in quick secession.

What's hilarious is that sinkholes are so much more common than the masses think :lol:

Love a good sinkhole. Very underrated natural disaster.

Yeah, but they're not usually gaping-ass holes that swallow buildings and kill people.

Ass holes how ironic.

Thankfully there are usually warning signs. The signs that there is a foundation problem (not always evident that its a sinkhole immediately) are obvious within the fascade of a building. Windows not shutting properly, cracking edging etc etc. are signs that something isn't right.

The scary thing is the amount of "sinkhole prone" material in Australia. Sandstone and some limestone (less prominent) are susceptible to groundwater intrusion and underground erosion which forms sinkholes. Older infrastructure is a problem because in the past construction was not carried out to account for seismic movement which can shear pipes. These days we generally recommend flexible fittings so that these sort of things do not happen. Ones big enough to actually swallow a building are very rare and usually uncovered during geotechnical investigations.

Generally they're made more prominent (in city areas) due to poor diversion of rain water, not noticing broken pipes and the associated affects on roads (wet sub grade will become less dense and begin to move).

That could be symptomatic of a few different things though, right? A house I was living in for a while last year had serious issues with the foundations, but it was old weatherboard and a relic from the late 20's or early 30's.

Oh of course, but they all warrant further investigation. Cracks, particularly in the corners of windows, doors/windows not closing or pooling water in the yard can be serious. However in saying that, sinkholes can be difficult to detect if the sinkhole is not obvious (the upper rock has not eroded as much as what is below it) and the movement and cracking is restricted only to plastic deformation of the underlying rock mass (rocks shearing and realigning along cracks) is only stress within the rock mass below the building.

From experience, large sink holes like in that photo (which is fake due its shape) will give many warning signs. This is only my opinion but I strongly doubt that a sink hole that large could form without partially failing first. The road it opened up in would have been f*cked for years before that happened. Lithic Labile Sandstone, whilst erosion prone, will not wash away that quickly no matter how acidic the groundwater is.

Up here in Brisbane we deal with a lot of failing old houses. Such old houses were usually founded on mass concrete pads where the prediction of reactivity of clay (clay will shrink and swell as moisture conditions change) and the footings will have cases where extreme weather conditions will cause irreversible damage to the footing.

We have dramas in the Ipswich area (if you know it?) with footings because people who don't know what they're doing go and build houses on reactive clay without first testing it. That stuff when it gets wet and then dries out can crack so badly you can stick your arm down the gap. That and mining under Ipswich was never accurately mapped and houses fall into underground caverns.

Actually, it's real. Google "Guatemala Sink Hole".

Really? I'm genuinely surprised by that given its shape. The shape is almost conical which I would not expect as I would have thought slumping within the sink hole would occur within soils and more weathered rock which would make it uneven and form caves.

I googled it and you're right. It's formation though is synonymous with what I have been saying. Rising groundwater in limestone rock formations and issues with leaking pipes.

Given where it is i'm sure their roads are shite anyway so my suggestion that warning signs would show in the pavement may not have been so obvious.