Today's Sinkhole

[Guy Profumo]

Today's Sinkhole

Braunton - North Devon

http://www.northdevonjournal.co.uk/video-huge-sinkhole-appears-near-braunton/story-29829483-detail/story.html

[Guy Profumo]

Today's Sinkhole

Braunton - North Devon: http://www.northdevonjournal.co.uk/video-huge-sinkhole-appears-near-braunton/story-29829483-detail/story.html

[Sits]

Today's Sinkhole

Now that's a Burrow.

[Kevin S]

Today's Sinkhole

http://metro.co.uk/2016/11/08/massive-sinkhole-opens-up-in-city-centre-during-subway-construction-6242576/

[Evariste Euler Gauss]

Today's Sinkhole

Fukuoka!

[Kevin S]

Today's Sinkhole

Quite. It's not your common or garden 'Oh look, the postbox has gone a bit wonky' kind of sinkhole, is it?

[Gangster Octopus]

Today's Sinkhole

Ripon apart...

[Kevin S]

Today's Sinkhole

Fixed-uoka

http://metro.co.uk/2016/11/15/sinkhole-what-sinkhole-japan-fills-huge-chasm-in-just-one-week-6258715/

[Evariste Euler Gauss]

Today's Sinkhole

That is impressive work!

[Sits]

Today's Sinkhole

In Sydney they'd still be arguing whose fault it was, and who was going to pay.

[Kevin S]

Today's Sinkhole

According to the Guardian, they actually completed the work within two days, with the rest of the week being spent inspecting it and signing it off.

[Kevin S]

Today's Sinkhole

http://www.harrogateadvertiser.co.uk/news/ripon-mp-urges-residents-living-near-giant-sinkhole-to-stay-vigilant-1-8238878

Meanwhile, the Ripon residents are still away, and Yorks Water only turned up yesterday to have a think about the sewers. Though the British Geological Survey seem to suggest that "this whole area is fucked," or words to that effect, perhaps.

[Hot Pepsi]

Today's Sinkhole

They're probably right.

My understanding is that just filling in the sinkhole and building back on top of it doesn't necessarily solve the, um, underlying problem. Because whatever waterflow dynamic washed out that rock is going to wash out whatever you fill it in with. And you also have to consider how what you're doing affects the water supply and runoff to other areas. You don't want to cause another problem by fixing the first problem.

In Japan, they probably decided, for traffic and PR reasons, that they had no choice but to get right on it. But I suspect that either they're at risk of it happening again or that they had reason to suspect that it was going to happen sooner or later and were ready with a plan.

[ursus arctos]

Today's Sinkhole

The fact that it was the proximate result of subway construction, rather than an underlying geological fault.

As Reed notes, it was likely a contingency they had planned for.

[longeared]

Today's Sinkhole

Another one in Sheffield...

[Guy Profumo]

Today's Sinkhole

longeared wrote: Another one in Sheffield...

"Eagle-eyed Barrie McAllen"

Because they're easy to miss, aren't they?

[San Bernardhinault]

Today's Sinkhole

A sinkhole 300x500 feet (and 50 feet deep) has appeared in the spillway of the Oroville Dam in northern California.

All the water they're releasing from the dam is just making it worse. And the lake is at 98% capacity, with rain and snowmelt still coming downstream.

They keep saying that the structure of the dam itself is fine, and that the rivers below Oroville have capacity to take all the surplus - and I'm sure they're right. But if I lived just below the tallest dam in the US and any of it was breaking apart, I'd be freaking out.

[ursus arctos]

Today's Sinkhole

The Sacramento Bee is doing an excellent job covering this

[The Awesome Berbaslug!!!]

Today's Sinkhole

Oh goody, ireland is going to get a bunch of new libraries.

[ursus arctos]

Today's Sinkhole

The situation has deteriorated significantly in Oroville



This evacuation order covers about 60,000 people

[San Bernardhinault]

Today's Sinkhole

This is more than just a sinkhole now. If I were anywhere near that I would now be properly scared. Even if the dam itself is fine, if you erode away the earthen emergency spillway, that could - I guess - eventually open up something equivalent to a breach. And they're already basically unable to control what's going downstream into the river.

Even worse, another massive storm is going to hit on Wednesday. Even down here they're talking 2-4 inches of rain at the coasts, 8 in the mountains. Northern Cal, and particularly the mountains, are likely to get a lot more.

[Ginger Yellow]

Today's Sinkhole

Seems kind of astonishing that they didn't think about erosion when designating the emergency spillway.

[WOM]

Today's Sinkhole

It looks like there are two spillways, though. There's the concrete chute (with the hole in it), which is the controlled spillway. And then on the left is an emergency spillway that basically appears to be like a lowered lip on the dam. It just dumps the water onto a grassy/treed hillside. I mean, I wonder if the engineers even figured that part would ever be used.

[Ginger Yellow]

Today's Sinkhole

Well, presumably they hoped it wouldn't, but planned for it being used. That's why it's an emergency spillway, and not just "a bit of land next to the dam". But if you can't use the emergency spillway without destroying the dam, it's worse than useless.

[evilC]

Today's Sinkhole

I watched some of the live coverage of that, last night (read 3am, this morning). It was mental! Given the scale of the lake (those photos taken during inspection of the crater were incredible) if that wall had gone, there would have been Marvel Cinematic Universe levels of destruction. :-/