on sinkholes


Eats up stairs

Alone or in pairs

And sucks em right into the ground

A hole, a hole, good god what a hole

Everyone knows the sinkhole!

In my senior year of high school, I took the Ecology class, which more specifically was Floridian Native Ecology And Other Supercool Things That I Wound Up Being Totally Into Despite Failing The Class. I had a lot going on at home and I was really good at hiding it. Still don’t know how I graduated. But that class gave me a firm grounding – hah – on the subject of sinkholes, aquifers, karst (not loess), saltwater inclusion, drought, water treatment, and all the other things that make Florida such a crumbly crust of sand to build upon.

Today I feel like sharing my knowledge with you. You are about to learn Sinkholes from a Genuine Lifelong Florida Girl. A defective one, mind, as I got the Estonian pallor and couldn’t tan at gunpoint, but a Floridian nonetheless. I instinctively do the stingray shuffle and I can identify bug bites by the welts they leave. I’ve earned my cred.

NOW THE DISCLAIMER: everything I am about to relate comes from the initial base of knowledge I learned in that class, bolstered by things I learned on the internet because I am a nerd and I like to spend hours learning about local geology in my free time. If I get something wrong, and you are in a position to know that for a fact and tell me what is the correct bit of information, PLEASE DO. Then I will edit this post, credit you for the corrections, and be more useful.

To explain this I need to get to very basic things and ancient history.

In the beginning, Florida was a sandbar barely peeking out from older, warmer oceans. The shellfish and tiny crustaceans that collected on it, over time, were calcified and compressed into limestone, which is porous, relatively fragile, and has a curious chemical reaction to acids like vinegar. (It was a fun day when we did Vinegar Rock Tests.) Limestone is made mostly of calcium carbonate, which is easily demolished by acids; if you drop ordinary white household vinegar on the stone, it will fizz impressively. It is not strong stuff, as rocks go, but it is perfect for the Floridan Aquifer. (Not Floridian. I don’t know why, don’t ask.)

Image via Wikipedia; fair use etc.

Image via Wikipedia & USGS.

The aquifer is made of porous limestone and water. Think of it as a saturated sponge, except the sponge is made of stone. This construction, a soluble waterlogged bedrock, is known as karst. There are lots of karst areas in the world; another that immediately comes to mind is the Yucatan cenotes, and I believe there’s another substantial one under the midwestern US, which has for decades supplied water to all of the farming that goes on out there.

This karst aquifer is a magnificent system. It has been tested by relentless nature for longer than humans have existed. It regulates itself. It functions just fine on its own terms. The problem is that those are not human terms.

Here’s how it goes: rain leaches through the soil and clay and sand, losing impurities as it goes. It sinks until it reaches the limestone bedrock which, being porous, absorbs and contains it. It stays there, circulating in a thousand beautiful subterranean rivers, until it burbles back to the surface in springs which feed rivers and streams.

Note I do not say lakes; although there are some spring lakelets (I’ve swum in beautiful Lithia which feeds the Alafia) most lakes in the Floridan Aquifer system are the result of sinkholes.

A sinkhole is simple enough. Water is dense and solid. So, too, is rock — even fragile rock like limestone. This delicate-seeming combination is quite sturdy and normally can support the ground above it. Sometimes, usually due to drought, the aquifer’s water level goes down. The limestone alone cannot support whatever is over it, so eventually gravity does what it does best and brings things crashing down. That is a sinkhole.

Most Florida lakes are sinkhole lakes: they began as sinkholes. Since water is always going down to the aquifer, it brings debris with it; if this plugs the hole, the water collects in the hole and becomes a lake. The lake then seeps into the ground and feeds the aquifer again, and all is well. On rare occasions, the aquifer level may drop and the hole may reopen, and where there once was a lake there is suddenly a dry mudflat.

Take a look at Google Maps, here; you can see all the natural sinkhole lakes, which are round, and then the manmade reservoirs which probably were built onto lakes, and are not round.

This is how karst functions. There is nothing wrong with this system. It’s been doing this since before our ancestors were still hiding from giant reptiles. The problem, as I said, is that it’s not very good for humans to live on.

Or, more accurately, I might say the problem is that humans do not know how to live on the karst.

For at least the past thirteen years, we’ve been under significant drought conditions. Not enough rain coming in, despite what we’d have you believe when we cry havoc about all the storms. Florida is also a very attractive place for farming, since the winters are so mild, and we can grow lots of things here that we cannot grow in many other places. All of this farming requires water, and lots of it: when the agriculture was getting started, it was not a problem, because the aquifer was full and seemed a perfect endless reservoir.

We’ve since learned that it is not, but we haven’t learned to slow down.

There are other elements at work here that I do not know as much about. Saltwater intrusion is one: when the fresh aquifer water is low, and it is near the sea, the saltwater will be pulled into the limestone. This does two things: it salinizes the fresh water and it erodes the limestone further. Another is the use of fertilizers, which acidify the groundwater and, again, cause more limestone erosion. The mixture of water and rock is precise, and dictated by nature: when this is out of whack, it all comes crashing in.

Refer to what I wrote above; when there isn’t enough water to support the limestone, it collapses into sinkholes. This has been happening more and more frequently lately, in places where it hadn’t been before, and that is directly due to pumping more water out of the aquifer than it can physically support.

We don’t seem to realize that we stand on water as much as on rock. Without the water, the rock can’t hold us.


fake-cough and watch them startle

Like most any other internet lemming these days, I have myself a facebook account. Mostly I use it to share silly images or videos, and keep in touch with (and/or track of) the bucketload of acquaintances I made down at Occupy.

The problem, of course, is that when you’re part of the Lefty Fringe, you wind up meeting with people who, while otherwise quite ordinary (for what passes for ordinary amongst the Lefty Fringers, anyhow) also go on about some really weird stuff.

Joke: How do you know if someone is a vegan? Don’t worry, they’ll fucking tell you.

Most of this I do not mind. It gets the raised eyebrow of WTF and then I scroll by. It’s entertaining, the same way looking at a thunderstorm and thinking “Oh, so that’s where they came up with that particular myth” is — or the way reading up on conspiracy theories is. It’s like having my very own X-Files, and I never keep getting reruns of that grotesque goddamn man-fluke episode. Everybody’s got their superstitions. Thing is, most of us will damn well keep ’em to ourselves and not write huge [TOXINS] internet screeds about [CHEMTRAILS] the secret messages in [WAKE UP SHEEPLE] the Emergency Broadcast System if you [FRINGE POLITICAL PARTY] use indigenous Incan morse code.

It’s okay, more or less. You got your thing, whatever. Long as you ain’t hurtin’ anybody else I will just be amused and then move on. That’s the key part: as long as you aren’t hurting anybody.

Which is why the anti-vaxers make me desperately wish for a widespread outbreak of measles.

I got into it with one of them today. I know better, I really do, I just could not help it. Trying to talk sense into these anti-vax prophets (I use that word deliberately) is about as effective as scolding a cockroach. The roach does not give a damn and you kind of look like an idiot for wasting your time. And yet — I get into it anyway.

I’m perhaps more aware of this than average folks, as several of my near and dear are either immunocompromised or at-risk in one way or another. Let me put it to you this way: a friend of mine travels the world researching pathogens. She is very very good at what she does, and way smarter than all of us. She told me that they make yearly flu-vax shortlist exceptions for people like me who can easily fight off a flu but could carry it to someone it could really damage. “You’re exactly the people we want to see coming in for vaccines,” is basically how she put it. But that isn’t enough, for me to get my yearly jab, because all these people who are important to me have to go out and be civilized around the morons who think a vaccine contains more mercury than a tin of tuna.

The great tragedy of my life: I can’t protect everybody from everything. Call me Garp.

When I see the garbage about vaccines linked to X or Y or Z, I can’t help it. I just see red. What I want to say is: “You are putting the people I love at risk. Get skullfucked by a syphillitic donkey.” But that, for some reason, is considered an over-the-top reaction to people acting like morons about highly contagious and deadly diseases.

Instead I link them to this post called ‘Why We Immunize,’ about childhood diseases and what they do. To date I haven’t gotten a single bit of backtalk. Perhaps it’s all the copied gravestone inscriptions. Teeny tiny coffins. How’d House put it? They come in so many colors; that’s good business. Frog green, firetruck red.

Go back to that link, now. Go read it all, especially the personal stories sprinkled in through the information and gathered fantastically in the comments. Smallpox. Pertussis. Measles. Polio — and that last one fascinates me most of all, because as part of the early-eighties cohort, I am lucky enough to have absolutely no idea what it’s like to live with that threat.

Again, I wish my grandmother was still around. I wish that at least on a daily basis, if not more, and for so many different reasons. Today the reason is that I want to know what it was like growing up when she did, in the twenties and early thirties, and then having kids who were bang in the danger zone when the biggest polio outbreaks swept the country in the late forties and early fifties. I do remember she had a vaccination scar on her upper arm – I think the right arm? – which she didn’t like to show. It must have been for smallpox. It was a round whitish scar, about the size of a pencil eraser. As a kid I was both fascinated (hey cool, scars!) and frightened (oh god, needles!) by it. She’d just laugh it off, because that little scar beat the alternative.

(I find, more and more, that I am turning into her — and that I do not mind it one bit.)

It boggles my mind to think about how many of the things I did were known vectors for polio: puddlehopping, swimming in pools or the beach, hell, even being out in public. The best way for oral-fecal bacteria to travel is through water. I’m imagining being a kid and weighing the cost of a potentially deadly disease versus an afternoon in a sprinkler. Or being an adult and trying to weigh that cost. I can’t wrap my head around it. I’ve been reading on this stuff all day, and I keep wanting to know more, the same way I always want to know about things nobody bothered to tell me about.

I saw a quote somewhere, recently, that theorizes any historical fiction set a hundred or more years ago is practically indistinguishable from science fiction, since technology and social organizations are so different. That is very true. Especially in this case: this polio stuff — Suzie, put your chin on your chest NOW! — sounds like something out of a Ray Bradbury book, with the invasive alien disease in the otherwise idyllic 1950s landscape. The day it didn’t rain, nobody came outside because the puddles could be toxic.

The only remotely similar experience I had was chicken pox – I’m old enough to remember pox parties, where everyone had to go hang out with the kid who got it, because there wasn’t a vaccine and it was best to get done with the damn disease as soon as possible. I had it for a week, raised maybe three spots, and spent my time bouncing around the apartment like a deranged Boston Terrier. My mother, somehow, also contracted it (then in her late thirties) and spent a week huddling in a dark room, miserable as all hell. But now there’s a vaccine for that, and that’s fucking fantastic.

The thing I hear the most — or, perhaps, the one that infuriates me the most — is this: “It’s extinct in the wild. The disease is dead.” No, it’s not. Do just a little bit of research: some are zoonotic, some are still endemic in other parts of the world, some are naturally occurring, and unless we keep inoculating and inoculating until we finally get every last person immunized, they never will be extinct.

Here’s what I wound up saying to that one idiot, and what I would happily like to say to all the rest of them, providing there are no syphillitic donkeys nearby….

“Check out a graveyard from the 19th century and feast your eyes on all those headstones for babies and children. Have ten kids; watch four live to adulthood, at least one likely disabled after surviving something that killed the other six. Shoot the dog when it gets rabies, die of suffocation and/or starvation because of tetanus, watch children drown in their own snot. Sounds like a blast, huh?”

I’ll stay over here in the 21st century, thanks. Y’all go be stupid somewhere way the hell away from me, and everyone I love, and everyone they love, and so forth. Which turns out to be everyone. Stay away from them all, except the skullfucking donkeys.