Volume 4, Number 3 July/August 1996
Maps produced from a NASA airborne sensor have helped officials save roughly $500,000 and about a year's time in cleaning up hazardous waste at the California Gulch Superfund Site in Leadville, Colorado. Using data from NASA's Airborne Visible and Infrared Imaging Spectrometer (AVIRIS), the U.S. Geological Survey produced maps to find sources of acid mine drainage and heavy-metal contamination at the site. The contamination is the result of more than 130 years of mining activities associated with the Leadville Mining District, according to Felix W. Cook, Sr., director of the Technical Service Center at the Bureau of Reclamation in Denver, Colorado.
NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, developed and currently manages the AVIRIS instrument, which is carried on a NASA high-altitude aircraft flying about 12 miles above sea level. "NASA's AVIRIS program has enabled more money to be used for actually cleaning up the hazardous mine waste materials currently contaminating this site," Cook said.
According to Robert Green, the AVIRIS experiment scientist at JPL, the sensor measures complete spectra of reflected sunlight that records in detail how light is reflected by molecules on the Earth's surface. These spectra provide an accurate picture of the surface chemistry. AVIRIS collects about 7,000 spectra per second. In the Leadville experiment, AVIRIS collected approximately 600,000 spectra in 90 seconds to determine the surface chemistry of an area on the ground that was six by 12 miles.
Using the spectral data, researchers can identify where acid-producing minerals have been mined and left on the surface. The U.S. Geological Survey developed an analysis program that recognizes the spectral signature of these minerals and allows researchers to map surface geochemistry. Sources as small as individual mine dumps can be identified.
"AVIRIS represents the ultimate vision of remote sensing," said Green. Using remote measurements of spectra to determine surface composition saves time and is much less labor intensive than other methods that involve sampling and laboratory analysis. Bureau of Reclamation officials believe that the AVIRIS data surface environmental chemistry mapping can be used for site investigations on many of the hazardous waste sites now included on the Environmental Protection Agency's National Priorities List.
The AVIRIS instrument is part of NASA's Office of Mission to Planet Earth, a long-term program to study the Earth's air, water, land and life as a global environmental system. Earth system scientists use AVIRIS spectral measurements to investigate topics in global climate and environmental change. Specific areas of research include ecology, geology, coastal and inland waters, snow hydrology, biomass burning, atmospheric studies and advanced calibration and algorithm development.
For more information, contact Robert Green at the Jet Propulsion Laboratory.
Phone: 818/354-9136, E-mail: rog@gomez.jpl.nasa.gov
Please mention that you read about it in Innovation.
Curator: Joe Goldfus
