NASA-funded scientists have created new worldwide mineral maps that could help mark the location of precious resources. These high-value data are now within the easy and inexpensive reach of a computer.
The developers of the maps used NASA thermal infrared (TIR) spectroscopy data to create maps of silicate, sulfate, and carbonate minerals in the planet’s arid and semi-arid regions. The maps, which complement other Earth sensor data, can provide scientists with important surface composition details for geological studies and resource prospecting.
Scientists developed the one-kilometer resolution maps using data gathered by two of NASA’s orbiting sensors: the ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) aboard the Terra satellite. The maps, now available through NASA’s Earthdata Search and the Land Processes Distributed Active Archive Center (LP DAAC), could be powerful tools for resource exploration and for understanding Earth’s geology.
“This achievement not only demonstrates how NASA Earth observation data can be used to identify regions for geological study and exploration, but also the power of cross-mission data synergy,” said Cole Krehbiel, project scientist for LP DAAC.
Identifying Minerals With TIR
Thermal infrared spectroscopy is a technique used to analyze the infrared energy emitted by materials. Each mineral on Earth's surface emits thermal radiation in its own way, producing unique spectral signatures that can be used for their identification. Scientists used TIR data from the ECOSTRESS and ASTER sensors to identify minerals, such as silica, spread across Earth’s arid regions—and it is the only known way to detect silica from space.
One big reason to study silicate deposits is to locate important resources. For example, lithium-bearing minerals, used in batteries and electronics, are often found in silicate-rich rocks such as quartz and feldspar. By mapping these rocks and minerals from space, researchers can identify areas that may contain other valuable deposits.
Maps of silicates have another benefit: signs of their alteration on the surface can indicate the presence of underground geothermal activity, which could point the way toward sites for renewable, geothermal energy production.
Searching for Silicates
The new mineral maps are the product of a recent study led by Federico Rabuffi from NASA’s Jet Propulsion Laboratory in California, and a follow-on to an earlier experiment.
“We were exploring the possibility of mapping gypsum with ECOSTRESS data as part of work related to understanding landslides in the Western United States,” said Rabuffi. “Once we knew we were able to identify gypsum, we decided to try using ECOSTRESS data to detect main rock-forming minerals, knowing it would be good for future exploration and missions.”
