The hard deep blue ice of Antarctica
Written by Kevin Brown
Is it Antarctica or heaven?
You can eat all the chocolate and other calorie-laden foods you want. That’s because a busy researcher camped on a glacier needs energy, to drill and carry 60-pound ice core samples.
It’s expected to stuff your parka pockets with Clif Bars, granola bars and more. Thick buttered pancakes for breakfast, and steak fried in butter with chilies for dinner also are good to consume.
It’s also quiet and peaceful.
In the Antarctic spring, the sun never sets. Checkerboard clouds can hang high in the sky. Ice crystal rainbows circle the sun.
“I love it so much. Everything makes me go, ‘Wow!'” says Sarah Aciego, assistant professor of earth and environmental sciences in LSA and assistant professor of climate and space sciences and engineering in the College of Engineering.
In November, she and Sarah Aarons, a Ph.D. student and research assistant in earth and environmental sciences, will continue the work they started in late fall 2013: Collecting glacial ice core samples from thousands of years past and comparing them to better understand climate change today.
They will return to Taylor Glacier, roughly 2,500 miles south of New Zealand, to collect vastly older ice samples from a different location on the glacier, and from a different glacial period, than they did two years ago. They left Oct. 31 during Antarctic spring, and will return to Ann Arbor for Thanksgiving.
Aciego is on her fourth research trip to Antarctica. This is Aarons’ second trip. “I think this time I am a little less scared because I know what to expect. I know how cold it will be (as low as minus 20 Fahrenheit) and how windy,” she says.
“The longest plane flight in the world” is how the pilot last time described the flight from Detroit to Sydney, Australia (15 1/2 hours). A second flight to Christchurch, New Zealand (four hours) follows. “They put you up in hotel,” Aarons says. “You try on your polar gear,”— red parkas as warm as sleeping bags, with National Science Foundation logo patches.
“That’s when it really hit me,” she says.
The next phase of the trip takes five to eight hours. This depends on the available airplane to fly to the main U.S. base in Antarctica, McMurdo Station. It is on Ross Island, 850 miles from the South Pole. Joining them in 2013 was Carli Arendt, a U-M Ph.D. candidate in earth and environmental sciences. She earned her degree in May.
The plane bound for McMurdo has bench seats and skis for landing. “When someone said you can see Antarctica and mountains and stuff, several people ran over to the window. You could see sea ice. It’s crazy to see the expanse of whiteness with land poking though here and there. I got really excited,” Aarons says.
Upon landing, it was 10 degrees and dry. “I’m from Alaska and used to cold temperatures, but it was bone chilling and a bit of a shock to the lungs,” Aarons says. Ross Island also is home to an active, smoking volcano.
Those arriving at McMurdo Station must join other researchers for survival training. They build igloos to sleep in, learn to set up tents and use tiny stoves to cook dinner. “They give you Army rations you mix with water,” Aarons says.
Some 1,000 people are at McMurdo in November and December. There is a large cafeteria and rooms like dorms. “It kind of felt like college with a bunch of adults,” Aarons says.
The base also has a cafeteria, a traditional bar and a coffee bar. There are seals as well as Adelie and Emperor penguins close to the base. People are not allowed to interact with penguins. “The smaller Adelie penguins are curious. They try to figure out what you’re doing,” Aciego says.
Researchers also perform a whiteout exercise. They put white buckets over their heads, are told to leave the building, and try to return. They also learn to use a CB radio, as there is no Internet connection on the glacier.
It’s a 45-minute ride by helicopter from McMurdo to Taylor Glacier. After arriving with their drill technician, Aciego and Aarons will set up yellow and grey tents and prepare to begin the work of drilling and collecting core samples.
Life on Taylor Glacier
“The first time you get here you can’t even believe it. It’s just so different. The ice is really, really hard deep blue. And they have these sun cups, maybe 6 to 8 inches in diameter, basically divots in the ice. It’s just incredibly beautiful,” Aciego says.
On Taylor Glacier, you can spot a “sundog” — the name for rainbows of ice crystals that circle the sun. It’s where silence is broken only by the whooshing of wind gusts that reach 80 mph or more, or the sound of helicopters or machinery.
Sometimes one spots stripes in the glacier. This suggests a volcanic ash layer got stuck in the ice and is now exposed. The stripes range in color from black to purple.
Because there are no trees, Aciego says, the sense of scale is unusual. “You’ll be looking out across the glacier and see a rock and think it’s a boulder — and you get there and see it’s the size of three houses.”
When setting up tents, stakes must be driven deep into the ice because the wind is ferocious. “We have had stakes break because of the wind,” Aciego says.
Good morning Antarctica
A normal day opens with lighting the propane stove to melt ice for water. “It’s so pure that we have to make sure that we increase the electrolytes we consume. Everything gets more salt in it than normal,” Aciego says. Two to three hours daily is spent melting ice for water.
“We’re eating or drinking hot drinks all day long,” Aciego says. Hot chocolate is popular, and so is hot Tang. “Purple Gatorade hot is not good, teas are,” she says. Coffee is avoided as it’s a diuretic, causing the drinker to take bathroom breaks.
The researchers also are constantly eating. One easily burns 7,000-8,000 calories daily operating the drill and carrying core samples. “Fifty to 60 percent of our time is spent on survival. You’re always talking or thinking about your next meal,” Aciego says.
Morning pancakes get lots of butter, and toppings ranging from Nutella to maple syrup to honey. For variety, they’ll go with chile rellenos in the morning. Lunch is usually eaten out of their parka pockets — crackers, granola bars or Clif Bars — and soup from a Thermos. “We eat a lot of soup. It’s an easy way to get electrolytes back,” Aciego says. For dinner, steak fried in butter with chilies works, and so does halibut with mashed potatoes and more butter.
The main focus of each day is drilling. Drills and drillers are supplied by Ice Drilling Design and Operations, an organization created by the NSF. Both researchers can run the drill. The hired driller sets up the drill and troubleshoots because things often go wrong due to weather conditions.
Sometimes, the drill has to be taken apart and the head replaced. This can happen under steady 50 mph winds. They typically work 12 hours daily, six days per week. “It’s the most tired I’ve ever been,” Aarons says.
In case of emergency, help can come from any of the area crews in the region, no matter what country. “It’s the way things go when you’re down there,” Aciego says.
Researchers are required to check in daily with McMurdo base via walkie-talkie-like Iridium phones. They also call in resupply needs. Satellite phones allow the researchers to call home from the glacier every few days or so.
Because it is close to sea level, Taylor Glacier is relatively warmer than further inland, where the ice sheet is 2 miles high.
“There were times when it was probably in the 30s. The sun is hitting the ice and reflecting back at you,” Aarons says. She once “put a ton of sunscreen on” and hiked more than two miles. “You could walk with a T-shirt,” she says.
“We are studying the dust particles trapped within the ice,” Aciego says.
Dust, or airborne mineral particles picked up by wind from places including the Sahara Desert or the Pampas of South America, are suspended in the atmosphere and can travel long distances in the upper troposphere. They eventually land in ice sheets, glaciers, oceans and terrestrial biospheres, she explains.
“The dust in ice can tell us a lot of information about the climate during its depositional period,” Aciego says.
For example, dust concentration is inversely proportional to temperature. This means that during colder periods (such as the Last Glacial Maximum), the dust concentration in the atmosphere was higher. This is due to windier conditions and more exposed continental shelves and lake beds.
“We can look at the dust concentration in ice core records, and infer whether the climate it was deposited in was a glacial or interglacial (warmer, like today) time period,” she says.
The purpose of this upcoming trip, Aarons adds, is to collect ice from a part of the glacier formed during the Eemian period (130,000-115,000 years ago), the last interglacial period — and compare it to ice formed in the current interglacial period, the Holocene. It ranges from about 11,700 years ago to today.
Aciego and Aarons collected samples in 2013 from 55,000 years ago to the present day, a period that covered the transition from the last glacial period to the current interglacial period.
“The overarching purpose of this field work is to investigate how local climate changes with retreats in sea ice and ice shelf extent, so that this information can be extended towards predicting changes in local climate in polar coastal regions,” Aarons says.
As with the samples collected two years ago, ice cores bundled and suspended below the helicopter will be flown to McMurdo Station, before they are loaded on a container ship bound for Alameda, California. They are constantly kept at minus 20 degrees Celsius or colder.
A freezer truck will bring the 10 new ice core samples to Michigan, and ultimately to the fourth floor of the C.C. Little Building. They will join earlier samples, kept in two freezers.
In June at C.C. Little, Aarons began the process of analyzing the core contents through a process where acid dissolves the dust collected from a melted core sample and the various elements are separated.
Aciego says, “It’s knowledge that could benefit future populations, and better inform them about the changes they’ll experience in their own climate change periods.”