Crops in Southwestern Kansas Watered by Groundwater (image) University of Arizona Share Print E-Mail Caption The circles from this satellite image are crops in southwestern Kansas watered by central pivot irrigation, which draws water from a well in the center of each field. The water comes in part from the Ogallala Aquifer, a layer of groundwater that lies under about 173,746 square miles (450,000 square kilometers) of the Great Plains -- an area that includes parts of eight US states. The water is between 30 and 100 meters below ground, and the amount of water in the aquifer varies greatly from region to region. The image was taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imaging instrument in the Terra satellite. Credit NASA Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.