Desert Reef

The desert in southeastern New Mexico is probably the last place you'd look for a coral reef, but that's just where a giant one formed millions of years ago.

Back during the Permian Era, when all the continents were stuck together in one big landmass that stretched from pole to pole, this region was underwater. Over the years, geologic forces beneath the Earth's surface pushed some of the reef high into the air. Today, the 400-mile-long, cave riddled, horseshoe-shaped reef is known as the Guadalupe Mountains.

This image was taken as the Landsat satellite passed over Carlsbad Cavern National Park region of the reef in May, 2000. The park entrance sits just to the west of White's City and the rest of the park stretches southwest from there. The green arc across the image is forested slopes of the mountain range; the shades of red indicate the dry, bare, and thinly vegetated valleys and basins below the mountains.

Unlike in the Permian Era - 280 to 248 million years ago - when the whole region was underwater, the rivers and streams today are bone-dry, and often only run after a rain storm. Water is more permanent in some of the canyons - such as Dark, Rattlesnake, and Slaughter - and the white dots that surround them are windmills used to power water pumps near wells.

The Carlsbad Caverns are a World Heritage Site, designated as such for the outstanding preservation of fossils of Permian Era ocean life.

--Bjorn Carey

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Credit: NASA Earth Observatory