Severinghaus hatched his plan for the reconnaissance ice drill with John Goodge, a geologist at the University of Minnesota-Duluth. The two met serendipitously at the Antarctic McMurdo Station cafeteria back in 2010.
“I said, well shoot, if you could drill to the bottom of the whole ice sheet, why stop there?” Goodge said. He shared his desires with Severinghaus to extract Antarctic bedrock, which would be another first for the science world.
The National Science Foundation has invested $10.5 million in the drill’s design and development since 2013. The drill the two designed together could nab a 50-meter rock core that would answer questions about Antarctica’s geologic origins.
Severinghaus and Goodge first tested the drill in the mountains of Utah. This December will be the third test of the drill in Antarctica and Severinghaus is hoping for positive results.
The 50-ton drill travelled by ship from Ventura, Calif., to Antarctica in 2015. It now waits for its makers to begin further testing at Minna Bluff near McMurdo Station where a 600-meter thick glacier sits atop bedrock.
The diamond-tipped RAID could eventually be used to extract three-billion-year-old Antarctic bedrock. Ninety-eight percent of the continent is covered in ice. Ice drilling is very expensive so few endeavor to dig into the rock below. Geologists like Goodge typically study already-exposed outcroppings that poke through the Transantarctic Mountains.
Goodge said studying the bedrock could uncover questions about Antarctica’s history like when ice sheets first formed or how the continent was assembled. Some evidence shows Antarctica and North America were once joined together as part of a supercontinent called Rodinia, Goodge said.
Glaciologists and geologists putting their heads together in Antarctica could yield important information about modern climate change. There’s strong evidence that parts of West Antarctica are melting at a very rapid rate, Goodge said.
“The bigger question is what’s happening in East Antarctica because there’s a lot more sea level rise potential if it begins to melt as well,” Goodge said. “So we really need to understand what those conditions are.”
As part of a separate effort to find more ancient shards, Severinghaus sent graduate student Jacob Morgan to work with a team at Princeton University. The team is drilling at Allan Hills, roughly 130 miles from McMurdo, where Morgan will spend eight weeks camping on blue ice — which is very old ice that’s not buried underneath a younger layer of snow. (See map of both locations here).
Researchers suspect ice in this region is old because fallen meteorites that struck Earth millions of years ago were found preserved on its surface.
Up to a certain point in history, scientists have compiled a record from all the information an ice core has to offer.
One mystery that a continuous ice core older than 800,000 years might explain is why there was a sudden change—in geologic time—in the Earth’s climate cycle between small ice sheets and large ice sheets. Scientists refer to these stages as interglacial and glacial.
Between 2.8 million and 1.2 million years ago, it took 41,000 years for the Earth to transition between being warm and cold episodes. But about one million years ago, that transition slowed to every 100,000 years.
In the context of Earth’s 4.5-billion age, a change that occurred just one million years ago is fairly recent, especially to a paleoclimatologist like Severinghaus.
“That’s an unsolved mystery,” Severinghaus said. “But is it telling us something we need to know for the future?”
Morgan, Severinghaus’ student, may also strike it lucky in his Allan Hills expedition and find the oldest ice in a shorter core that takes even less time to drill.
Morgan and Severinghaus will return to Scripps in spring with ancient ice, and hopefully new discoveries, in tow.
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– MacKenzie Elmer
More information: https://www.nature.com/news/super-fast-antarctic-drills-ready-to-hunt-for-oldest-ice-1.18649
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