Source of Your Sand Castle

Caribbean beaches are beautiful, even by the standards of tropical beaches, which are pretty high to start with. They're also made largely of poop. Parrotfish poop, to be specific.

(Okay, full disclosure: I’m not currently on a beach. I write this on a Sunday morning, in my robe, from my man cave next to the house here in suburbia. I’m safe. And thanks for caring.)

Move past the thought of that, and it’s a fascinating process:

The brilliantly colored parrotfish possesses a hard beak it employs for eating coral. The fish grinds up the coral in that beak to get at algae and other marine microorganisms growing on it, digests the algae, and then poops out the ground-up coral as a fine sand.

Parrotfish produce a LOT of sand, too. A single green humphead parrotfish can produce more than 200 pounds of sand each year. As much as 85% of the sand on many of these beaches is produced by parrotfish.

Watch it in action HERE, if you dare.

People used to think that parrotfish just ate coral for the polyps and were damaging the reefs. It turns out, though, that most parrotfish species go primarily for dead coral, clearing it for new coral to grow. So, they’re providing a sort of public service.

Parrotfish also eat large amounts of sea sponges, which grow faster than coral and can smother young ones. As it turns out, our parrotfish have a largely symbiotic relationship with the corals they eat. And as we learn more and more about the world, we begin to find more and more of these relationships. 

It's not just the Caribbean that owes its beaches to parrotfish. The Maldives, the white sand beaches of Hawaii, and other locations around the world do, as well.

Gorgeous white sand beaches in tropical areas around the world are all made of poop. A little gross, I know. Which is exactly why I'm telling everyone: I’m simply trying to clear out a few of you so that my next beach experience is less crowded.

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Quotable

So, Yard Ramp Guy: Let's duel.

“Lacrosse is fast paced and I like fast paced games. It's demanding physically and has the hardest conditioning of any sport. You are always running if you are not sprinting. It's constant movement.” 

— Aaron Gray

The Gamburtsev Discursive

There's a mountain range on Earth that no human has ever seen.

The Gamburtsev Mountain Range is about the size of the European Alps and are as rugged as the Rocky Mountains. Why has no one ever seen the mountain range? Because it's buried underneath 10,800 feet of ice in Antarctica.

Oh, and water flows uphill there.

One of the more interesting aspects of the Gamburtsevs is the ruggedness to them. They're more than a hundred million years old. By now they should have eroded enough to resemble the Appalachians, instead of looking like the Rockies.

Scientists today think the mountain range has actually been preserved by the ice above it—a counter-intuitive result, since absolutely nothing erodes mountains faster than glacial ice in normal circumstances.

The Antarctic ice sheets are so thick, however, that the ice starts to behave in a bizarre manner. As the pressure grows stronger farther and farther down into the ice sheet, the freezing point of water starts to drop lower and lower, until liquid water eventually exists at the bottom; the freezing point of water down there is simply just too low. The pressure actually forces the water to flow uphill!

We've identified other mountain ranges that were presumably buried underneath ice sheets during the Ice Age, including the Torngat Mountains in Canada and the Scandinavian Mountains.

If the ice in Antarctica ever melts, one effect will be that the mountains (currently with an average height of 8,850 feet) would rebound upwards. Ice sheets are so heavy that they actually press the continental crust downward into the mantle.

Removing the Antarctic ice sheets would cause the Gamburtsevs to rebound back up to 10,800 feet in height.

Thankfully, we're not likely to see them any time soon. Even the worst models for global warming don't predict that rebounding scenario as extremely likely. Which is a good thing because it would raise the sea level some 200 feet.

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Quotable

Dear Yard Ramp Guy: Oh yes—a quote for you:

“O, what a tangled web we weave; When first we practice to deceive!”

— Sir Walter Scott

The Aral Sea: 1989 (l) and 2014 (r).

In the early 1960s, the Aral Sea—in between today's Uzbekistan and Kazakhstan—was one of the four largest lakes on the planet. By 2007, it had reduced to ten percent of its former size.

The Aral Sea's name roughly translates to “The Sea of Islands,” a reference to, shockingly enough, its many islands. It played a vital part in the region's history, economy, and culture, as well as feeding much of the region with rich fisheries. And then, in the early 60s that started to change.

The Soviet Union began a series of projects in the region. The largest of these was the diversion of the two main rivers that fed the Aral Sea, the Amu Darya and the Syr Darya, for the purposes of agricultural irrigation.

The USSR planned to use the water to turn the region into one of the world's largest cotton exporters, and this actually worked, for a little while. As many of the irrigation canals were poorly constructed, they often lost as much as 75% of the water flowing through them.

And so the Aral Sea began a slow but steady decline in water level. The rate of evaporation increased as more and more water was taken from the rivers for irrigation purposes. The Soviet Union was aware that the lake would disappear. They simply weren’t concerned. As more water evaporated and wasn't replaced, the salinity of the lake steadily increased, by almost 500%.

By 2007, at ten percent of its normal size and split now into two lakes, the North and South Aral, it had a salinity almost three times that of the ocean, killing almost all its natural life. (Though it still wasn't as salty as the Dead Sea.)

The huge plains left as a result of the sea evaporation are coated with salt and toxic chemicals (weapons tests, industry, and agricultural runoff.) These nasty sediments are picked up by the wind and carried great distances, causing cancer and other ailments all over the region. There's so much of the toxic dust that the region now regularly has poisonous dust storms.

Some conservation efforts have slowed the evaporation of the sea. Engineers have begun to repair and strengthen the irrigation canals in order to minimize the losses through them. The northern half, in Kazakhstan, has been dammed off from the southern half, resulting in a rise in sea level in the northern half, with salinity levels dropped to the point where life can survive there again.

There's little hope for the southern half. Uzbekistan has no interest in reducing its irrigation demands, or efficiency, and has instead begun working on exploiting the exposed seabed for oil.

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Quotable

Okay, Yard Ramp Guy — S-omething to quote (in case yours isn’t quotable):

“Sadness is but a wall between two gardens.”

— Kahlil Gibran

Air and water are our two most heavily-used natural resources and, though not as obvious, dirt is number three. What's number four, though?

Surprisingly enough, it's sand.

Endangered?

We’ve used sand for construction since the time of ancient Egypt, if not longer. We utilize certain high-grade sands for glass, with other grades for detergents, toothpaste, cosmetics, solar panels, and computer chips.

The biggest use? Concrete. Essentially, concrete is just sand and gravel bound together by cement.

You might wonder why I'm distinguishing between dirt and sand. They're both just stuff on the ground, right? Well, no. Dirt contains a high degree of biological debris and is great for growing things in. (It often contains sand.) Sand is just ground up bits of minerals, usually quartz.

As common as sand is, turns out that it's also a finite resource. Humans use more than 40 billion tons of sand and gravel every year, and the demand is getting severe enough that riverbeds and beaches all over the world are being emptied out. We can't use desert sand because it's too rounded to bind together well—a result of wind erosion rather than water erosion.

And shortages are beginning to crop up. The absurd construction boom in Dubai has so denuded local sources that they're literally buying and shipping their sand from Australia now.

As local riverbeds, beaches, and quarries run out, sand miners have started to turn to the seafloors, vacuuming up sand from the seabed while dealing marine ecosystems massive amounts of damage.

Alarming ripples.

At least two dozen Indonesian islands are simply gone now due to Singapore's sand requirements (its artificial land construction projects make it the largest sand importer in the world). Environmental damage in the region has gotten so bad that three countries have already banned exports of sand to Singapore.

Construction sand now even has a black market, profitable enough that violent organized crime groups are building up around it.

The environmental damage from the sand trade is immense. This hardly gets any attention in much of the world. After all, it's just sand, and for millennia now we've used “grains of sand” as a metaphor for something countless.

Our sand turns out not to be countless after all.

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Quotable

Ahem, Yard Ramp Guy — T-ry this one on for size:

“Take away the cause, and the effect ceases.”

— Miguel de Cervantes