The Return to Tunu

Glaciers and ice sheets form season by season, year by year, as layers of snow accumulate and compress into ice. Particles including desert dust, ash from explosive volcanic eruptions, soot from wildfires, and during recent centuries and millennia, industrial pollution also become trapped in the ice, capturing detailed records of past climate and environmental history.

By drilling into polar ice and removing long cylinders of ice called ice cores, scientists can access these ancient records. The ice core samples are then analyzed and used to answer questions about Earth and its past, including human history, which is the primary focus of this project.

The journey to collect an ice core is a story in itself. In May 2022, a team led by scientists from DRI in Reno, Nevada departed for Greenland. They were joined by ice drilling, Arctic logistics, and mountaineering experts. Together, the team set out to collect a 440 meter-long ice core representing 4,000 years of Earth and human history.

In 2013, several members of the same research team visited Greenland and collected a 214-meter core from a nearby Tunu drilling site. The ice core that they collect this year will extend their previous findings by more than 2,000 years.

After collecting the new ice core, the samples will be transported to the U.S. and analyzed in DRI’s unique ice core lab in Reno. Traces of volcanic ash, anthropogenic emissions, and other substances captured in the layers of the ice will provide new insight into human history from about 4,000 to 2,000 years before the present.

In mid-May, 2022, the DRI ice core team flew from Reno to Albany, New York, to quarantine and make final preparations for their trip to Greenland. Safety protocols for the expedition included social distancing and masking while traveling, and periods of quarantine after each leg of the journey. Because medical care options are limited in Greenland, the health and safety of the team was a priority.

For much of their time on the ice sheet, the team did not have access to the internet or phone service -- but they were able to send short text messages back to DRI from a Garmin inReach two-way satellite communicator. Their daily updates are below.

On May 19, the team continued on to Greenland via a military plane from Albany to Kangerlussuaq. In Kanger, the team continued to quarantine and prepare for the next leg of their journey. They gathered equipment, practiced setting up tents, sampled the Greenland cuisine (musk ox burger, anyone?), and took an afternoon trip to the edge of the Greenland ice sheet.

Next, the team traveled by ski plane to EGRIP, the site of the East Greenland Ice Core Project ( https://eastgrip.org/). A US military ski plane carried the ice vehicles that the team will use to travel to their drilling camp in Tunu.  

After leaving Kanger and heading out onto the ice, the research team had no access to phone or internet, but were able to send back daily text updates from the ice sheet via a satellite communicator. Photos were added to this StoryMap after their return to civilization in July!

The ~70 insulated boxes filled with the Tunu ice cores will be stored at ~-27 C in the storage vault at EGRIP (thanks again to EGRIP for all their support). They will be picked up by a NY Air National Guard LC-130 heavy-lift ski plane on July 19, transported to Kangerlussuaq, and then placed by Polarfield staff (thanks in advance) in a freezer until the July 21 southbound “cold-deck” flight to Stratton Air Base near Scotia, NY. There the boxes will be offloaded into a waiting freezer truck and immediately driven ~1800 miles to the National Science Foundation Ice Core Facility (NSF-ICF) in Denver, CO ( https://icecores.org ) where they will be transferred to the -36 C archive room. Joe, Nathan, Sophie, and Drake will meet the ice at the NSF-ICF on July 25 and, with help from NSF-ICF staff (thanks in advance), spend two weeks making additional preliminary measurements and cutting samples from the cores in the -24 C examination room. These samples will loaded into insulated boxes and driven >1000 miles to our unique ice core lab in Reno, NV where they will be analyzed in the coming months for >30 elements, isotopes, and chemical species.   

Notes from the team on various aspects of life in an ice core camp. Photos are from the Tunu2013 expedition and are included as examples of what an ice core camp looks like. We will update the StoryMap with photos from the Tunu2022 expedition when the team returns!

Keeping our feet healthy and warm requires daily boot maintenance. Ensuring that the insolation is dry is critical. Each night before bed we pull the foam boot liners and two layers of insoles out of our Baffin boots and hang them (including the boots) off strings at the top of our sleeping tents. The air near the top of the tents is warm from solar heating and dry so the boots, liners, and insoles usually dry out overnight. Sometimes the liners don’t dry so then we alternate with spare liners every other day, giving the liners 24 hours to dry. Changing socks at mid-day also helps! (Message sent 6/3/22)

Our camp is laid out in three distinct areas separated by about 50 m on flagged routes for low visibility travel: drilling/science, kitchen/food, and sleeping tents. The layout is intended to minimize polar bear danger, with the kitchen/food area downwind and the sleeping tents upwind (the prevailing wind is down-glacier from the southwest). The assumption is that in the (very unlikely) event that a polar bear is nearby, it will follow the food smells upwind, thereby encountering the kitchen/food area first and the sleeping tents last. We’ll see. (6/3/22)

With outside temperatures generally less than -10 C and typically between 0 and 5 C in the science dome, staying warm is difficult. The science dome is a semi-rigid, 4.3 m (14 ft) diameter structure assembled from 21 separate fiberglass panels using 165 nuts and bolts. I (Joe) acquired it so that we would always have a semi-hard-sided structure in camp for polar bear safety. Right now I’m wearing wool socks inside insulated snow boots, lightweight wool long underwear bottoms, medium weight fleece pants, and windproof over pants. Above the waist, I’m wearing a lightweight wool undershirt, fleece sweater, down vest, down parka, a fleece neck gator, and a wool hat – all of this while sitting in the science dome. We wear this pretty much all day. Only the kitchen tent, especially when a propane stove is on, is warm enough for lighter clothing so we linger over breakfast and dinner. (6/6/22)

Generating water for a camp of 9 takes some effort. Melting snow on a propane stove is much harder without starting with some water so we guard our seed water carefully. The snow comes from a designated “clean snow zone” not far from the kitchen tent and is mined using a dedicated “clean shovel and two dedicated 5-gallon plastic buckets. Snow is added repeatedly to the seed water on the stove and then the full pot poured into a 10-gallon insulated water cooler – that hasn’t frozen yet. Making water for the camp is an excuse to hang out in the kitchen tent with the propane stove fired up — generally not bad duty. (6/8/22)

Each member of our team has an individual sleeping tent. All but Eidur are using 8 ft by 8 ft Arctic Ovens that are a little over 5 ft tall at their highest point and have an interior floor space of about 6.5 by 6.5 ft. Each of us also has a folding cot, although some prefer to sleep on the floor and use the cot for storage and sitting. Solar heating in the Arctic Ovens is impressive. I’ve had a sensor logging the temperature at the very top or peak of my tent and at floor level for the past four days. Although we are camping well above the Arctic Circle at 78 degrees N and the sun doesn’t set at this time of year, there is still a significant daily or diurnal cycle in solar radiation. The result is a strong 24-hr cycle in my tent temperature.  During the storm a few days ago with little direct sunlight and high winds, the temperature at floor level during the night was -12 C (10 degrees F) and the temperature at the top -10 C (14 F). Daytime temperatures were still cold, -4 C (25 F) and +4 (39 F) at floor and peak level, respectively. Now that the sun is shining and the winds are light, last night’s temperatures were -4 C (25 F) and +1 C (34 F) at floor and peak levels, while this afternoon’s highs were 4.5 C (40 F) and 16.5 C (62 F). The large, 12 C temperature gradient over the approximately five feet between the floor and peak in the tent means that sleeping on the cot is much warmer than sleeping on the floor - glad I’m on the cot! (6/8/22)