Images

The Edrengiyn Nuruu forms a transition zone between the Mongolian steppes to the north and the arid deserts of northern China to the south.

Where the Volga River flows into the Caspian Sea, it creates an extensive delta. The Volga Delta is comprised of more than 500 channels, and sustains the most productive fishing grounds in Eurasia.

Ephemeral Lake Carnegie, in Western Australia, fills with water only during periods of significant rainfall. In dry years, it is reduced to a muddy marsh.

This pan sharpened color infrared image of Sioux Falls, South Dakota is from the first scene acquired by Landsat 7's Enhanced Thematic Mapper Plus (ETM+) sensor on April 18, 1999. The image is shown using the near infrared, red, and green bands (Bands 4,3,2).

The Ganges River forms an extensive delta where it empties into the Bay of Bengal. The delta is largely covered with a swamp forest known as the Sunderbans, which is home to the Royal Bengal Tiger.

On the border between Chile and the Catamarca province of Argentina lies a vast field of currently dormant volcanoes. Over time, these volcanoes have laid down a crust of magma roughly 2 miles (3.2 km) thick. It is tinged with a patina of various colors that can indicate both the age and mineral content of the original lava flows.

A marsh-like area borders the Demini River in northwestern Brazil. The Demini eventually joins the Amazon River.

Resembling splotches of yellow and green paint, salt-encrusted seasonal lakes dot the floor of Western Australia's Shoemaker impact structure. The structure was formed about 1.7 billion years ago and is currently the oldest known impact site in Australia.

South America stretches more than 7,500 kilometers from the warm Caribbean Sea almost to Antarctica. Waters from the eastern slopes of the Andes Mountains drain into mighty rivers, such as the Amazon, that traverse rain forests, grassy plains, and dry plateaus to eventually reach the Atlantic Ocean.

Between the fertile Euphrates River valley and the cultivated lands of the eastern Mediterranean coast, the Syrian Desert covers parts of modern Syria, Jordan, Saudi Arabia, and Iraq.

An intricate maze of small lakes and waterways define the Yukon Delta at the confluence of Alaska's Yukon and Kuskokwim Rivers with the frigid Bering Sea. Wildlife abounds on the delta and offshore where sheets of sea ice form during the coldest months of the year.

Western Asia, the world's largest continent, occupies one-third of the Earth's landmass. Although divisions are somewhat arbitrary, Western Asia encompasses the Middle East and countries that surround the Caspian Sea, including Kazakhstan and Russia.

The third largest continent, North America is a land of many facets: frozen tundra, rugged mountains, high plains, deserts, and lowland forests.

Eastern Asia is dominated geographically by China, which stretches from the Tian Shan Mountains in the west to the sheltered bays of the Yellow Sea in the east.

Europe is a modestly sized continent, only Australia is smaller, but its long, irregular coastline is riddled with bays, inlets, islands, and peninsulas, both great and small.

Soaring, snow-capped peaks and ridges of the eastern Himalaya Mountains create an irregular white-on-red patchwork between major rivers in southwestern China. The Himalayas are made up of three parallel mountain ranges that together extend more than 2,900 kilometers.

The Mediterranean Sea physically separates--but in other ways unites--southern Europe, the Middle East, and northern Africa.

Mexico and Central America together form the southern half of the North American continent. From the rugged deserts of the Baja Peninsula to the steamy rain forests of Panama, the region is a land of great contrasts.

A scene along a road in Senegal, photographed in 1994 by U.S. Geological Survey Scientist G. Gray Tappan as part of his work on West African land cover. Tappan photographed the scene again in 2004.

This is a screenshot of 1992 Land Remote Sensing Policy Act Congressional Record. The full document is available below. 

1992 National Land Cover Database (NLCD) displaying the diverse range of land cover types across the United States. The NLCD was first developed in the early 1990s as a collaborative effort by multiple federal agencies to provide consistent and comprehensive land cover data.