This simulated natural color scene shows a 30 by 36 km (19 by 22 miles) region in the German state of North Rhine Westphalia (located in midwestern Germany). The myriad rectangular patches are agricultural fields; light green hues show where crops are growing and grey hues show bare soil. Darker green hues show forested areas. The various blue-grey clusters of pixels seemingly linked together by dark thin lines are towns and villages connected by roads. The data used to produce this scene were acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), flying aboard NASA's Terra satellite, on August 26, 2000.
On the right side of the image are three enormous opencast coal mines (bright white and dark blue patterns). The Hambach opencast coal mine has recently been brought to full output capacity through the addition of the No. 293 giant bucket wheel excavator--the largest machine in the world. This excavator is twice as long as a soccer field and as tall as a building with 30 floors. To uncover the 2.4 billion tons of brown coal (lignite) found at Hambach, five years were required to remove a 200-meter-thick layer of waste sand and to redeposit it off site. The mine currently yields 30 million tons of lignite annually, with annual capacity scheduled to increase to 40 million tons in coming years.
The United States’ highest rate of coal production is in Wyoming, with almost 4 million short tons extracted in 2004. The majority of this coal is burned to generate electrical power within the United States, but a small percentage is also goes to Spain and Canada. The Powder River Basin in the northeastern portion of the state is the most productive of Wyoming’s coal fields. The extensive coal deposits—ranging in thickness from 21 to 53 meters (70 to 175 feet)—formed over 38-66 million years ago. The source of organic material for the coal originated in swamps, estuaries, and deltas associated with the regression (retreat) of a large inland seaway that occupied central North America during the Cretaceous Period, which spanned the years between about 144 to 65 million years ago.
Surface mines and fly-ash deposits in the Tuzla Basin reveal the region’ long history as a coal-production hub for Bosnia and Herzegovina. This image of the altered landscape was captured on September 21, 2003.