Coming to a city near you: Weird/terrifying holes, Part II
Sunday, December 15, 2013, 6:55 -
A few weeks ago, having noticed our readers' apparent love for stories about sinkholes, we put up a weekend feature listing seven notable weird/awesome/terrifying holes around the world. It turned out to be the most popular weekend feature we've ever done.
DON'T MISS IT: Read Part I of our series on weird/awesome/terrifying holes
We get the message, so here you go: Seven MORE weird/awesome/terrifying holes, from giant underground caverns, to man-sized crystals, to glimmering, colourful pools.
Every now and then, a giant sinkhole swallows part of a Texas town
We led off our previous installment of this semi-series with the Bayou Corne sinkhole in Louisiana, where a ruptured underground salt dome was slowly devouring bits of swampland.
Here’s what it looks like when that happens on dry land:
That’s the ragged edge of a 45 m deep and 182 m wide sinkhole that was apparently once a wooded field. The United States Geological Survey says it likely happened when a rapid injection of fluids caused part of the 10-km subterranean salt dome to to dissolve (other sources blame erosion at the top of the dome).
In 2008 when it first opened up, it was a terrifying experience for everyone involved as it swallowed several vehicles and structures and sent the small Texas town of Daisetta into a panic.
Five years later … looks like everyone has learned to live with it. This source notes one couple who saw the hole open up not far from the foundations of their under-construction abode ended up finishing the home a year and a half later. A nearby highway whose surface dropped 10 cm was reopened several months later.
As for the sinkhole itself, it’s just a salty pool now.
It seems two similar holes opened up in previous decades, so we guess the good people of Daisetta are probably just getting used to it.
Oil workers drill in the wrong place, cause a lake to vanish
Come to think of it, we’d think people in neighbouring Louisiana would also be used to the landscape swallowing itself – especially after this 1980 episode which caused a 500-hectare lake several feet deep to temporarily vanish.
It seems an oil exploration team drilling in the lake miscalculated their trajectory and punctured a shaft of an underground salt mine beneath the lake. The trickle of freshwater dissolved several salt pillars in one of the shafts that were deliberately left unmined as roof supports.
When they gave way and the shaft collapsed, the entire above-ground derrick fell over and vanished into a huge whirlpool, and onlookers watched as the lake levels dropped drastically.
The water dropped so much that a canal leading from the lake to the Gulf of Mexico was reversed, and seawater began to tumble into the crater in a 50 m waterfall that at the time was one of the tallest in the state. Swept into the abyss were 11 barges that had been travelling on the canal.
A couple of days later, a shallow freshwater lake had become a deep seawater one, but incredibly, no one was seriously injured or killed, and nine of the 11 sunken barges floated back to the surface eventually.
As for the damage to the ecosystem … well, it seems nature finds a way. This source says several plant and wildlife species happily settled into some new digs.
The Cave of Swallows is deep enough for base jumping
Moving on from man-made boo-boos to the wonders of the natural world, we’d like you to take a look at this shot from the floor of Mexico’s Cave of Swallows.
See that tiny spec against the distant, sunny sky? That’s an abseiler, and he’s descending around 376 m from the sinkhole rim down to its wide-bottomed floor. This caving site says it takes around 20 minutes to reach the bottom, and another 40 minutes to scale the rope back topside, using clamps.
While you’re down there, try to avoid stepping on the scorpions, centipedes and legions of other creepy-crawlies that live in an environment featuring metres-deep fields of guano. The toxic air is so thick down there, anyone intending to actually explore the three-football-field wide floor is supposed to take a breath mask, or risk coming down with a fungal lung infection.
If you fancy a faster route to the bottom, the cave is super popular with base jumpers. It boasts the second deepest entrance drop in the world, allowing daredevils several seconds of freefall before pulling their chutes (the cave was featured in the popular documentary series Planet Earth).
But even before it became an extreme sports Mecca, the cave attracted onlookers eager to glimpse the thick flocks of birds (mostly white collared swifts and green parakeets) that swarm in and out of the cave at dawn and dusk.
There are thousands upon thousands of them, even after running the gauntlet of the occasional bird of prey that hovers above the sinkhole hoping for an easy meal.
The downside of the cave’s growing popularity: Increasing tourism has been great for the local economy, but it's believed to be disturbing the birds, so more restrictions have gradually been placed on would-be adventurers.
Xiaozhai Tiankeng is actually a sinkhole WITHIN another sinkhole
If a sinkhole ever does open up under your property, you can rest assured that it almost certainly won’t be as big as China’s Xiaozhai Tiankeng, the largest sinkhole on Earth.
What you’re seeing up there is actually a sinkhole in another even larger sinkhole, together making up a drop of around 662 m at the deepest.
It took more than 100,000 years for the elements to cut the hole this deep, and while nearby locals knew about it for centuries, it was “rediscovered” by surveyors in 1994.
Since then, of course, it’s a haven for tourists. If you look carefully at the pic above, you can just see the faint line of a staircase along the vertical wall of the lower sinkhole. It’s too far to see, but it’s made up of around 2,800 steps in total.
That’s an awful long way to walk, so if you like, you can take the shortcut, like these base jumpers:
The hole is so far across, they have to go along a cable to reach a point where they can drop directly into the lower sinkhole. And when that first jumper lets go of the cable around 30 seconds in, watch how much freefall time he has before he has to pull his chute. Looks to us like around 10 seconds.
And unlike Mexico’s Cave of Swallows, there’s no semi-toxic, bug-ridden guano pit waiting for him, but a thriving forest ecosystem, with more than 1,200 species of plant and rare animal species like the vulnerable clouded leopard.
“Tiankeng,” incidentally, means “Heavenly Pit” or “Sky Hole.” They named it well.
Three small holes lead down into the giant Majlis al Jinn
Except for three relatively small holes, the Majlis al Jinn in the Gulf state of Oman is completely closed off from the sky.
We wouldn’t have known about it had a pair of married geologists not wondered about said holes in aerial photographs, and trekked through the wastes to investigate.
So upon shimmying into what seemed to be just a series of wide-ish crevasses like this...
…They ended up finding, to what we can only imagine was their incredible surprise and elation, that they opened up into this:
The Majlis al Jinn – the “meeting place of the Jinn,” spiritual beings popularly known to western dwellers as “genies” – was the second largest underground cavern in the world when those intrepid geologists stumbled upon it (of course it was known to locals since forever). It’s since dropped to around ninth place, but it’s still spectacular, at 120 m deep and 310 metres at its longest.
It seems those three relatively small holes let in just enough sun and moonlight to create the impression of an eerie subterranean world, so it’s not surprising that, as usual, spelunkers and extreme sports enthusiasts began to flock to it.
The result? The Omani government closed the cave to the public in 2008, citing high profile, but illegal base jumping stunts by Red Bull and other corporations as being damaging to the site.
Red Bull, at least, countered that it was all above board, since their particular 2007 dive, with noted daredevil Felix Baumgartner, had been well advertised and known to Omani media, and that Baumgartner’s team included experts that helped minimize the impact.
Regardless of what the truth is, the cave remains closed for now, although the Omani tourism ministry says they’re working on re-opening the cave with more tourist-friendly access paths and attractions.
We can’t wait.
Mexico's Cave of Crystals is unbelievable (and dangerous)
No Genies in this cave beneath a mine in Mexico, but you’d be forgiven for wondering whether you should look over your shoulder to find Superman sternly demanding what you’re doing in his Fortress of Solitude.
You might need to be super-human to make it through the Cave of Crystals, though. The cave, which is kept drained of water by mine pumps, is around 58 degrees, with 100 per cent humidity.
Those conditions were key to forming those incredible gypsum crystal pillars (some of them are 11 m long) when the cavern was filled with mineral-rich water, but the thick air is filled with the same minerals – a serious danger to the lungs of explorers (read this account by a BBC reporter who had to wear a special suit and breath mask when he visited).
The cavern’s days may be numbered, since the surrounding mine will close eventually and the pumps keeping the chamber dry and accessible will be shut down, but geologists say the cavern may be one of many such in the region.
Hopefully future explorers will turn up another beautiful work of natural art just like it.
The Grand Prismatic Spring is a fever dream
If the Crystal Cavern is nature’s sculpture studio, Yellowstone’s Grand Prismatic Spring is nature’s surrealist hobby.
And yes, that is a real place on Earth, not an alien landscape or graphic artist’s pet project.
It’s a 37-metre-deep hot spring, with the water gushing to the surface at a temperature of 70C. Those vivid colours are mats of specialized bacteria adapted to survive in the high-heat environment of the spring.
Aside from the traditional green cholorophyl, the bacteria are infused with other pigments called carotenoids, which change colour based on the intensity of the sun, and how near the bacteria are to the centre of the spring.
The centre, meanwhile, is an intense blue because the water scatters light the same way lake or ocean water does.
It couldn’t be another bacterial trick … the heat in that location is just too much to support any kind of life, bacterial or otherwise, so if you ever go visit, don’t worry about taking your swimsuit.