14 DAY TRIAL // A technology originally developed for spacecraft investigating the Red Planet is now being used for the identification of underground aquifers here on Earth. Such structures, buried deep beneath the planet's surface, have never been investigated with radar sounding technology before.
This methods was created so that NASA spacecraft orbiting Mars could get some idea of how the planet's underground looked like. Before long, experts realized that a similar approach could be taken here on Earth as well, for mapping freshwater aquifer distribution in detail.
This approach was tested recently by an international team of experts led by NASA investigators. They used an airborne radar sounding instrument to collect data on aquifers scientists did not know existed.
An additional advantage that this technology has is that it can provide additional details on the hydrological conditions of Earth's desert, both now and in the distant past. The data collected in this manner could then be used to extrapolate how global warming will change these conditions.
Such studies are becoming increasingly important as deserts expand, due to the process of desertification. Already, more than one fifth of the planet's dry lands are covered in deserts, including areas in the United States, Asia, North Africa and the Middle East.
The 40-megahertz, low-frequency, airborne sounding radar prototype that was used for the new study was developed by experts at the NASA Jet Propulsion Laboratory (JPL), in Pasadena, California. The team was led by research scientist Essam Heggy.
The investigation took place in northern Kuwait, where investigators tried to determine the location of hidden, unknown aquifers using this novel method. Experts from the Institut de Physique du Globe de Paris, in France, also participated in the study and in constructing the instrument.
The team was completed by specialists from the Kuwait Institute for Scientific Research (KISR), in Kuwait City. Together, the researchers spent 14 days flying with a sounding radar-equipped helicopter over the arid landscape.
They made a total of 12 low-altitude passes, at 1,000 feet (305 meters) or less, probing two known aquifers. Water tables at these locations were at 66 to 213 feet (20 to 65 meters) below ground. The instrument had no problem confirming the known data.
“This demonstration is a critical first step that will hopefully lead to large-scale mapping of aquifers, not only improving our ability to quantify groundwater processes, but also helping water managers drill more accurately,” KISR Division of Water Resources director Muhammad Al-Rashed explains.
“This research will help scientists better understand Earth's fossil aquifer systems, the approximate number, occurrence and distribution of which remain largely unknown,” Heggy goes on to say.
“Much of the evidence for climate change in Earth's deserts lies beneath the surface and is reflected in its groundwater. By mapping desert aquifers with this technology, we can detect layers deposited by ancient geological processes and trace back paleoclimatic conditions that existed thousands of years ago, when many of today's deserts were wet,” he concludes.