Although helium is perhaps best known for inflating balloons (and making your voice sound funny when it’s inhaled), it is also a critical component in many machines and industrial activities, mostly because it is so stable and doesn’t react easily with other chemicals. Liquid helium is used as a coolant for the magnets in high energy accelerators, such as the Large Hadron Collider, near Geneva, and in MRI machines; as a gas, it’s applied in certain types of welding and is also used to help pressurize the tanks in some types of rocket engines.
Even though helium is one of the most abundant elements in the universe, there’s concern that it may be running dry here on planet Earth. Helium, like natural gas, is typically retrieved after it comes bubbling up from deep within the earth. But until now, no one had ever intentionally uncovered a helium field. Rather, the gas has typically been discovered accidentally during other industrial activities, usually oil and gas exploration.
Today, a majority of the world’s helium comes from the United States, and a large portion of those supplies are currently held in the Federal Helium Reserve, a vast underground store beneath parts of Texas, Oklahoma and Kansas. Other sources include gas fields in places such as Qatar and Russia.
Altogether, the U.S. Geological Survey estimates that there are about 35 billion cubic meters worth of helium reserves left in the world, and until now, scientists were not sure where they might discover more. But a team of researchers from the University of Oxford and Durham University in Britain made it their mission to find out.
“We’ve had a research project for the last few years to find new resources of helium,” said Chris Ballentine, chair of geochemistry at Oxford and a member of the research team. “It’s a very significant problem for society in that helium usage has become more and more important in high-tech industry and also medical use.”
After spending some years investigating the types of geological characteristics and exploration strategies necessary to find new helium deposits, the team partnered with helium exploration company Helium One, which had made an “amazing discovery,” Ballentine said.
“They’d noticed some old literature going back to the 1960s suggesting that nitrogen- and helium-rich gases were just bubbling out of the ground” in parts of Tanzania, Ballentine said.
Upon closer investigation, the researchers realized that the region was “exactly the type of geological environment we’d been postulating would be perfect for the helium discovery,” Ballentine said. In that area, the continental crust is thought to be splitting apart, generating volcanic activity that the researchers think can help release helium from ancient rocks, deep underground, where it has been stored. Once the helium is released from the pores in the rock, it can migrate upward and settle in the area’s underlying geology in much the same way oil and natural gas tend to do.
The team sent postdoctoral researcher Pete Barry of the University of Oxford to collect samples from the area, which PhD candidate Diveena Danabalan of Durham University later analyzed. The team found that the gases bubbling out from the ground in that area were composed almost exclusively of nitrogen and helium.
Using seismic images and knowledge of helium geochemistry, independent experts working with the team have suggested that just one part of the rift valley may contain about 1.5 billion cubic meters of helium — about twice the amount stored in the U.S. Federal Helium Reserve and nearly seven times as much helium as is usually consumed globally in a year.
The gas can be accessed via drilling in the same way that oil and natural gas typically are — and while it’s unclear what types of environmental concerns might apply when it comes to industrial activity in that part of Tanzania, Ballentine noted that no oil or natural gas, which would have the potential to contaminate the surrounding land if released, have been detected in the area.
In general, the team’s technique provides a relatively simple mechanism for locating helium in other places.
“The techniques that we’re using are very much similar to the approach the oil industry has used to find gas and oil,” Ballentine said. “We look for source rock, we look for a mechanism to release the gas from the source, and we look to understand how gases migrate and look for trapping structures.”
There are several other promising sites in Tanzania that the team hopes to assess next, Ballentine said. In the meantime, the discovery provides hope that there will be helium powering MRI machines and rockets alike for years to come.
Correction: On Twitter, we were instantly deflated by clever readers who noted that images of hot-air balloons were not a very good accompaniment to this story. The image has been changed accordingly.
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