Earth As Art 3

A study in shades of blue and brown is actually one of the harshest landscapes on Earth. This glimpse of Africa's Sahara Desert, located near where the borders of Mali, Niger, and Algeria converge, is truly a no man's land, a world of sand and rock without roads or settlements.

This abstract in browns and grays from central Algeria shows that some parts of Africa's Sahara Desert contain much more than dunes of wind-blown sand. Barren ridges and fragmented mountains (lower right) border a vast expanse of arid plains etched with a complex system of dry streambeds.

Tin Bider is an ancient and eroded meteor crater on the Tin Rhert Plateau in the Algerian Sahara. Tin Bider is nearly 6 kilometers (3.7 miles) in diameter and was caused by a meteorite impact in this region of northern Africa roughly 70 million years ago. The other streaks near the crater are unrelated to the impact event.

Like a watercolor in which a brushstroke of dark green has bled into a damp spot on the paper, southern Africa's Okavango River spreads across the pale, parched landscape of northern Botswana to become the lush Okavango Delta.

In the American Southwest, transitions from one ecosystem to another can be dramatic and abrupt. This certainly is true in northern Arizona, USA, where the parched Painted Desert, shown here in a palette of purples, adjoins Sitgreaves National Forest (shades of green), a realm of pine woodlands with abundant wildlife.

Central Asia's Tibetan Plateau is justifiably nicknamed "the roof of the world"-its average elevation is more than 4,500 meters (14,764 feet). It is the world's highest and largest plateau, covering an area roughly four times the size of Texas. Tectonic forces have long shaped the Tibetan Plateau's crumpled and uplifted mountain ridges.

During the last ice age, Akimiski Island in Canada's James Bay lay beneath vast glaciers that pressed down with immense force. As the climate changed and the ice retreated, Akimiski began a gradual rebound.

Skeletal extensions of land reach like bony fingers across a section of Liverpool Bay along the northern edge of Canada's Northwest Territories. Only small villages are thinly scattered in this remote and inhospitable region of Arctic tundra bordering the Beaufort Sea.

Straight highways fan out like spokes on a wheel from the Argentine city of San Luis. To the right of the city are croplands that resemble colorful confetti. Founded in 1594, San Luis lies at the tip of the Sierra de San Luis and is largely surrounded by flat-to-rolling fertile plains.

The intricate lines angling and criss-crossing over the landscape are roads in extreme southwestern Kazakhstan. The turquoise areas to the left are salt flats and marshes, some parts of which are submerged (dark blue). The water body is Sor Kaydak, which was once a gulf of the Caspian Sea.

Do you see a scary face looking back at you? The hollow-appearing eyes, narrow nose, and slash of a mouth are inundated patches of shallow Lake Eyre (pronounced "air"). Deep in the desert country of northern South Australia, Lake Eyre is an ephemeral feature of this flat, parched landscape. When seasonal rains are abundant, water fills the lakebed to some degree.

A popular holiday destination, the Lake District in northwestern England is a region of picturesque mountains and long, narrow lakes. Most of the lakes lie in U-shaped valleys that were carved by glaciers during the last ice age. Morecambe Bay, below the Lake District, opens into the Irish Sea.

In the style of Van Gogh's painting "Starry Night," massive congregations of greenish phytoplankton swirl in the dark water around Gotland, a Swedish island in the Baltic Sea. Phytoplankton are microscopic marine plants that form the first link in nearly all ocean food chains.

Vivid colors and bizarre shapes come together in an image that could be an imaginative illustration for a fantasy story. This labyrinth of exotic features is present along the edge of Russia's Chaunskaya Bay (vivid blue half circle) in northeastern Siberia. Two major rivers, the Chaun and Palyavaam, flow into the bay, which in turn opens into the Arctic Ocean.

What appears to be a stroke of thick red paint is actually a remarkable interplay of light and cloud in the Canadian Rockies. Angling through them is part of the Rocky Mountain Trench, a valley that extends from Montana, USA, to just south of the Yukon Territory.

Small, blocky shapes of towns, fields, and pastures surround the graceful swirls and whorls of the Mississippi River. Countless oxbow lakes and cutoffs accompany the meandering river south of Memphis, Tennessee, on the border between Arkansas and Mississippi, USA. The "mighty Mississippi" is the largest river system in North America.

Ethereal swirls of grease ice appear turquoise against the midnight blue of the northern Baltic Sea near the Aland Islands (red) between Finland and Sweden. An early stage of sea ice formation, grease ice consists of a viscous mix of tiny ice crystals and resembles an oil slick on the ocean's surface.

The dark heart in this vivid African landscape is the Erongo Massif, an isolated, sheer-walled mountain that rises 1,200 meters (3,937 feet) above arid Namibian plains. The massif is a remnant of a gigantic volcano that was active roughly 150 million years ago. At some point, the volcano's center collapsed in upon itself under the weight of overlying lava.

Seen through the "eyes" of a satellite sensor, ribbons of Saharan sand dunes seem to glow in sunset colors. These patterned stripes are part of Erg Chech, a desolate sand sea in southwestern Algeria, Africa, where the prevailing winds create an endlessly shifting collage of large, linear sand dunes.

The Caicos Islands (pronounced KAY-kohss) in the northern Caribbean are a popular tourist attraction, renowned for their beautiful beaches, clear waters, scuba diving, and luxury resorts.