Denmark’s Aarhus University has developed a new technology to measure surface-based groundwater in a more accurate, cheaper and faster manner.
Groundwater is a critical source of freshwater for many billions of people, but climate change, pollution and over-exploitation are making it more difficult to find suitable areas as a groundwater source.
Nuclear Magnetic Resonance (NMR) measurements are the only technique available today that enable direct non-invasive measurements of the water.
NMR measurements, however, have a disadvantage: Background noise from the electricity grid, for example, can interfere with the signals, making it exceedingly difficult to measure the very weak electromagnetic field given out by hydrogen atoms in groundwater.
The Aarhus team is hoping to change that with the help of data transmission and modeling.
According to the scientists, their new technology sends much cleaner signals than have so far been possible using NMR-based measurements.
It offers a quick, stable, reliable and inexpensive alternative for mapping groundwater throughout the world.
This should enable scientists to make a more detailed map of the hydrogeological and geological structure of the subsurface, even in inaccessible areas.
Shedding light on their technology’s prowess, associate professor Jakob Juul Larsen says that they can sort of direct the microphone towards the specific sound source they want to hear, and through a number of identical pulses almost ‘force’ a clear signal from the hydrogen atoms in the soil.
The computer can then piece together the signal they receive to an accurate reproduction of the original signal using data modeling.
“Using this new technology, NMR measurements are now a cheap, fast and, above all, very accurate tool for mapping and characterizing groundwater systems,” notes Geoscience assistant professor Denys Grombacher.
“There are problems with groundwater all over the world, and the really good news is that, using this tool, we can better map the groundwater and thereby take better care of it.”
Image and content: CC0 Public Domain/PhysOrg
