London: Scientists, using a new approach to gas exploration, have discovered a huge helium gas field in Tanzania, which could address the increasingly critical shortage of this vital yet rare element.
Helium is critical to many things we take for granted, including MRI scanners in medicine, welding, industrial leak detection and nuclear energy.
However, known reserves are quickly running out. Until now helium has never been found intentionally - being accidentally discovered in small quantities during oil and gas drilling.
Researchers from Oxford and Durham universities in the UK, working with Helium One, a helium exploration company in Norway, has developed a new exploration approach.
The first use of this method has resulted in the discovery of a world-class helium gas field in Tanzania.
The research shows that volcanic activity provides the intense heat necessary to release the gas from ancient, helium-bearing rocks.
Within the Tanzanian East African Rift Valley, volcanoes have released helium from ancient deep rocks and have trapped this helium in shallower gas fields.
"We show that volcanoes in the Rift play an important role in the formation of viable helium reserves. Volcanic activity likely provides the heat necessary to release the helium accumulated in ancient crustal rocks," said Diveena Danabalan, PhD student at the Durham University.
"However, if gas traps are located too close to a given volcano, they run the risk of helium being heavily diluted by volcanic gases such as carbon dioxide, just as we see in thermal springs from the region," Danabalan said.
"We are now working to identify the 'goldilocks-zone' between the ancient crust and the modern volcanoes where the balance between helium release and volcanic dilution is 'just right'," she said.
"We sampled helium gas (and nitrogen) just bubbling out of the ground in the Tanzanian East African Rift valley," said Chris Ballentine, Professor at the University of Oxford.
"By combining our understanding of helium geochemistry with seismic images of gas trapping structures, independent experts have calculated a probable resource of 54 Billion Cubic Feet (BCf) in just one part of the rift valley," Ballentine said.
"This is enough to fill over 1.2 million medical MRI scanners," he said.
"The impact of this and expected future helium discoveries will secure supply for the medical scanning and other industries," said Jon Gluyas, professor at Durham University.
"We can apply this same strategy to other parts of the world with a similar geological history to find new helium resources," said Pete Barry, from University of Oxford.
"We have linked the importance of volcanic activity for helium release with the presence of potential trapping structures and this study represents another step towards creating a viable model for helium exploration," Barry said.
