Scientists don’t wear lab coats on the Greenland ice sheet.
With temperatures as low as -60 degrees Celsius and arctic winds pushing 200 m.p.h., collecting ice cores on the world’s second-largest chunk of ice is like an extremely dangerous mountaineering expedition.
Considering the desolation, the ice sheet might as well be the moon.
But the climate is changing, and those ice cores that tell the story don’t remove and analyze themselves. Humans must do it, and then they—and the data—need to survive.
There were clear stretches between the long storms. The team stayed busy regardless, usually working between 7:30 a.m. to 11 p.m. or midnight, seven days a week.
Hill often wore 40 pounds of clothing to keep warm. Each heavily insulated boot weighed five pounds. Hill calculates he burned 7,000 to 10,000 calories per day and lost 16 pounds in the first year, in part because he shoveled between three to four tons of snow every day preparing data collection sites for firn density pits and helping with 19 to 20-meter ice core drillings each day.
When storms cut visibility nearly to zero, the team set up fluorescent flagging tape on bamboo poles every few feet between tents. Team members were required to carry GPS devices at all times, no matter how near they intended to stay to base. Hill’s device got him home safely after being caught in a whiteout just 1 kilometer away.
The healthy fear that kept the team true to its safety protocols gave way several times to panic. Once, a team member grew increasingly insistent that a raging nighttime storm could sweep away or bury their tents.
Sure enough the camp was buried. The team dug its way out in the morning and went about its business.
“People were at times terrified who hadn’t been in the field before, and rightly so,” Hill said. “It’s a humbling, extreme situation when you can’t see your hand in front of your face.”
It was all worth it for the data, Hill said.
Analysis of the core samples provide the most comprehensive evidence yet that warming temperatures have increased melting on the ice sheet in the last 30- years, and that the trend accelerated around 2012. Not only that, the data revealed that the increased volume of melted ice changed the way the ice sheet behaves, exacerbating the problem.
Despite a solid appearance – the ice sheet looks like a never-ending slab – historically, it’s porous, slurping up ice melt like a sponge. That’s no longer the case. Thick layers of melted ice are freezing, creating dense and impermeable top layers that force the next year’s melted ice to run into the ocean. (To learn more about the science at play, check out this excellent National Geographic article on the ice sheet, “Something strange is Happening to Greenland’s ice sheet.”)
The sea level is rising, which is an obvious concern. But the changing nature of the ice sheet could carry additional side effects. The addition of more cold, fresh water could alter the region’s habitat, starting plankton and rippling throughout the ecosystem.
The core samples dug by Hill and the team revealed distinctive layers of snowpack and impermeable ice that formed each year. The first layers of dense ice were several inches, Hill said. Those dramatically grew after 2012, when the amount of ice that melted increased seven-fold. The largest layer Hill saw was roughly nine feet thick.
Hill didn’t need a science doctorate to take alarm.
“We were going back through history, seeing the ice change in such dramatic fashion,” he said. “Seeing it go form inches to nine feet, that really scared me. If I can understand that as a non-scientist, that made me realize this is a lot worse than media are reporting.”
Of course, observing effects of climate change isn’t worth much without quantifying data. A previous scientific campaign lost almost a year’s worth of data from a data station. As the team’s data manager, it was Hill’s job to ensure the statistics, notes, photos and video gleaned on the dangerous trip made it home. That meant relying on the Crucial SSDs and saving every file in three different drives.
“We’re traversing hundreds of miles at a stretch. Computers don’t do well with that transport,” Hill said. “That data is so critical. We needed to make sure it came back safely.”
The laptops were fitted with pre-heating circuitry, and heater cores, allowing them to function in the extreme cold. To that end, only SSDs could have done the job. Traditional hard disk drives use a mechanical arm that moves to access data on a spinning platter. Those moving parts seize in extreme cold. SSDs, which have no moving parts, were up to the task.
As a result, the traverse yielded the largest data set on the health of the ice sheet ever gathered. Researchers will study the data at the two institutions that supported the trip, NASA and the Cooperative Institute for Research in Environmental Sciences at University of Colorado Boulder. But that’s just the start. The data is open-source, meaning it’s available to the world. The data will support climate change research efforts around the globe for at least the next decade.
That’s a happy ending for what could have easily been a doomed trip. Scientists have died on the ice sheet. Hill – the outdoor survivalist – felt death was near a handful of times. Of those, the final days of the first traverse were the most harrowing.
The six-man team had one last data station to visit before returning to the pickup point. The team had just outlasted a two-week storm. Everybody wanted off the ice sheet.
“We decided to risk a traverse back to the main station because we were itching to get back home,” Hill said. “We took a quick break 18 miles in for a snack. Then the whiteout conditions caught us.”
Barely able to see, the team mounted the snowmobiles and crept, in a diamond pattern, into the white at 10 m.p.h. All Hill could see was the back of the snowmobile 10 or 15 feet in front of him. The leader navigated via GPS. Hill’s mind started playing tricks.
“I could have sworn we were turning right the entire time” he said. “I knew our leader was going straight, but my brain was telling me we were turning circles.”
The team crept blindly at low speed in a whiteout and 90 m.p.h. winds for nearly 50 miles. Finally, they reached the station at 11 p.m. and struggled to set up a 15-man tent in the screaming wind to hunker down for the night.
In two perilous trips, Hill said that long haul in the whiteout shook him the most.
“It was extremely invigorating. I’ll just put it that way,” he said. “You feel your vulnerability pretty strongly.”
Hill felt lucky to make it home from the first campaign. He halfway hoped his wife would forbid him from going back to the ice sheet. He eventually recommitted to the mission, in part because he believed the mission is essential.
“I basically came back in shock,” he said. “After calming down a good month or so, my brain got back into gear. I started thinking, ‘I can do this again. This is important. We need to get this information gathered and get it out to people.’ ”