What happens is that the wind blows the sand up the shallow slope on the other side, and then, as each sand grain hits the top of the ridge, it cascades down on the inside of the crescent, and so the whole horn shaped dune moves.

This is a volcanic ridge.

But 10 miles down the ridge...

The climbers got on the southeast ridge.

Is this the bus for Park Ridge?

And there were climbers on that summit ridge.

This is the view looking at the southeast ridge.

This is a view taken along the summit ridge.

39 percent of homes on Pine Ridge have no electricity.

We worry about cocaine coming from the Andean Ridge north.

OK, this is a view taken on the summit ridge itself.

So they went out and they modeled a computer model of a sand dune.

The mid ocean ridge runs around like the seam on a baseball.

This is all you've got. You're very exposed on the summit ridge.

Some of those grains may then accumulate on a massive scale, into a sand dune.

But, by now, you're probably asking, how am I planning to solidify a sand dune?

Unemployment on the Pine Ridge Indian Reservation fluctuates between 85 and 90 percent.

They had to move this village in 1987 as a huge dune threatened to swallow it.

So, we pushed the piles down through the dune, and we create an initial bacterial surface.

This is what a real one looks like, on the Juan de Fuca Ridge.

And here comes dune scape, coming up out of the courtyard, and there it is fully built.

First of all, I was embarrassed because I had not read the novel Dune at that time.

We're going to look at the mid ocean ridge, a 40,000 mile long mountain range.

Both Denmark and Russia have been devoting significant resources to exploring the Lomonosov Ridge. Denmark has hired Swedish icebreakers for repeated expeditions, and Russia has been deploying special submarines to obtain samples from the ridge and the ocean floor.

So to test this crazy idea, we developed a small dune buggy prototype vehicle to test the feasibility.

Her name is Pam Moran in Albemarle County, Virginia, the foothills of the Blue Ridge Mountains.

The tuberculosis rate on Pine Ridge is approximately eight times higher than the U.S. national average.

They took photographs, they fed the photographs into their computer program, and that computer program shaped a sand dune and then took that sand dune shape and turned it into at their instructions, using standard software with slight modifications a set of instructions for pieces of wood.

She was sitting with someone who I presume was her mother, and they were talking about the novel, Dune.

Other activities are taking place in areas such as sand dune fixation, forest management and the promotion of agroforestry.

Because it's along the axis of the mid ocean ridge where the great crustal plates are separating.

What looks like a cloud behind the summit ridge is actually snow being blown off the summit.

The mid ocean ridge is a huge mountain range, 40,000 miles long, snaking around the entire globe.

How to assess countries claims to Arctic territory hinges on the status of the Lomonosov Ridge, a vast formation that rises from the sea floor and stretches 1,800 kilometers from Greenland to the East Siberian continental shelf. Everyone agrees that it is a ridge.

In a desert plain in Tanzania, in the shadow of the volcano Ol Donyo Lengai, there's a dune made of volcanic ash.

And the climbers up on the ridge were that much higher, 2,000 feet higher, and completely exposed to the elements.

Todd and Pete got up to the summit ridge, up in here, and it was a scene of complete chaos up there.

The Pine Ridge Reservation, the subject of today's slide show, is located about 75 miles southeast of the Black Hills in South Dakota.

And this kind of life and death of hydrothermal vent communities is going on every 30 or 40 years all along the ridge.

There's a ridge right in the middle of the picture, up above where that arrow comes in, that shows you that a little bit.

I need not remind you that this was David Lynch's version of Dune, in which all of the characters were sexy and deformed at the same time.

According to the reports, soil conservation continues to be given high priority by the organizations in their efforts to preserve the environment, alongside sand dune fixation strategies.

In 1994, Oak Ridge National Laboratory in Tennessee completed production of all the iridium parts that will be used to encapsulate the Pu 238 fuel.

OK. Those climbers were up near the summit, along that summit ridge that you see up there, and I was down here in Camp Three.

It's what's technically known as a barchan, and the entire dune walks across the desert in a westerly direction at a speed of about 17 meters per year.