Why the spring peak in Greenland field activities?

Field activities in Greenland are often confined to spring and summer. In autumn and winter, low temperatures, snowfall, the lack of sunlight, and more frequent storms do not provide optimal working conditions. Besides, the most interesting processes to study primarily occur in the warm season, such as the melting of the glaciers and ice sheet.

There are two distinct peaks in Greenland field activities. The first is in spring, for those people who need to get out there when things are still frozen, but when daylight and weather conditions are workable. The second peak is in mid-to-late summer, when weather conditions are best, melting is strongest, and the ice sheet margin and tundra is snow-free and more accessible. In between there is a potentially less pleasant period with often soggy conditions, and billions of mosquitoes. With the summer peak getting underway, let’s see what the spring rush is all about.

Installing instruments before the warm season

A good reason to get over to Greenland in spring is when you want your instruments in place to monitor what’s happening during the “warm” season, when plants grow, animals reproduce, and glaciers melt. Or, in the case of the University of Fribourg, when meltwater is generated at the top of the snowpack on the ice sheet. The Swiss scientists have now returned several times to the same sites in the lower accumulation area. They study how much meltwater gets refrozen in the cold snow underneath the surface, how much runs off into the ocean, and how this will change in time. Greenland Guidance provided weather forecasts for them to optimize their activities and prepare camp for storms, if needed. This spring their field team had two weeks on ice with surprisingly good weather conditions.

The University of Liverpool placing a weather station next to a fast-moving glacier (photo: James Lea).

Another team out there this spring was the University of Liverpool, who where installing GG-built instruments at a fast-flowing glacier in southwest Greenland. They are investigating a glacier that has retreated a lot in the past few years. When such a glacier experiences melt, an already complex system becomes even more complicated, for instance because of large pulses of meltwater originating from ice-dammed lakes along the sides. Or from rain events. With their instruments up and running in mid-May, they timed it well.

In May and June, the Geological Survey of Denmark and Greenland (GEUS) visited GC-Net weather stations high on the ice sheet. This is part of their annual maintenance efforts that take place in spring to make sure all systems are up and running during summer. We were invited along to help out. Each station takes several hours to service, but the more people can help, the faster the Twin Otter airplane can return to town. The machine experienced engine trouble, but luckily this happened at the airport before departure, and not on or over the ice sheet.

Preparing for takeoff to do maintenance at GEUS GC-Net sites (photo: Ken Mankoff).

Snow conditions

A second reason for the GC-Net maintenance to take place when it is a bit colder has to do with snow conditions. The scientists need to dig deep snow pits to asses the mass of the snow that fell since the last site visit, and this is done best before seasonal melting happens.

For others a cold snow layer means increased safety. Ski traversers crossing the ice sheet have to pass crevasse fields, and this is done much more safely if there is a solid snow bridge on top, deposited during winter. When snow gets wet because of melting, such bridges get weaker, and falling through them into a deep crevasse becomes a serious threat. That’s why the wind-powered kite-ski traverse team led by Bernice Notenboom did their expedition before the melt season, in May. They traveled an astonishing distance of nearly 2000 km from ice sheet base Dye-2 to the northwestern town of Qaanaaq. During their expedition they were confronted with several storms that we warned them about via satellite transmission.

The Winds of Change kite-ski camp

Preparations for summer

Often spring activities are mere preparations for summer expeditions. Take for instance the greenhouse in Narsaq in south Greenland. In order for charitable organization Greenland Trees to be able to plant trees along south Greenland fjords at the end of summer, their new greenhouse had to be prepared for growing seeds and cuttings in April and May. It took a lot of effort, but is was truly nice to notice how happy locals are with the project, and how eager they are to collaborate – including schools.

The Greenland Trees greenhouse in Narsaq.

In terms of volume, most of our clients and collaborators are scientists or camera crews, asking where to rent a boat, how to get permits, which locals to interview, and how to get to a remote site. But we also provided support to Swedish company SKB, who have been running and funding science projects in the Kangerlussuaq region over the past 15 years. In preparation of a groundwater sampling campaign to occur at their unique bedrock borehole in late summer, we went ahead and inspected the state of their equipment, inventoried their storage, and downloaded data collected by sensors deep underground.

The SKB bedrock borehole at the ice sheet margin.

With SKB discontinuing their Greenland science projects as of 2022, Greenland Guidance was selected to take over their surface hydrology project situated in the Two Boat Lake catchment. This is an exciting opportunity, and we welcome suggestions for scientific collaboration by anyone who reads this. More about the TBL project in an upcoming blog post!

Two Boat Lake with the ice sheet in the background.

Busy times

For Greenland Guidance, spring is the busiest time of year. This is when we support field parties remotely, take part in fieldwork ourselves, prepare for fieldwork in summer, and custom-build instruments for summer deployment. Nowadays we are also building and refurbishing instruments for use in the Himalayas for Utrecht University and the Indian Institute of Technology Roorkee. And we’ve expanded our area of expertise by now also focussing on ocean sciences through collaboration with MetOcean in Canada, and our new instrument platform Polar Monitoring.

Sky Detectives – a BEA documentary featuring Greenland Guidance

Recently the "Sky Detectives" documentary aired on French television showcasing the high level of expertise by the French bureau for investigating civil aviation safety, the BEA. Central to the storyline is a project the BEA coordinated in Greenland, in which Greenland Guidance played its part.

On 30 September 2017 a large Airbus A380 airplane lost parts of its number 4 engine, which were scattered over the Greenland ice sheet. Luckily nobody got hurt. An investigation into the cause of the accident was started immediately, but the critical engine piece needed for the investigation, the fan hub, was nowhere to be found in the area searched by helicopters. A new expedition could not be launched until the next spring due to the onset of cold and dark Greenland winter. So in spring 2018 an airborne radar team and a ground radar team combed the 15 km2 search area to find … nothing.

Director Louis-Pascal Couvelaire interviewing GEUS researcher Liam Colgan for “Sky Detectives”.

The search for the (now two-part) fan hub proved extremely difficult because the heavy titanium had impacted into the snow surface. It got covered by increasing amounts of winter snow as time progressed, rendering visual detection impossible. Also the radar systems initially proved impractical as subsurface ice layers, of which there are many in this part of Greenland, could be mistaken for engine pieces.

Having improved their processing techniques of the airborne radar data, by 2019 Onera, the French aerospace lab, had identified a few potential targets for the ground team to inspect. And shortly after, on the last day of an expedition suffering from several storm delays, a team led by researcher Ken Mankoff of the Geological Survey of Denmark and Greenland (GEUS) detected a metal object at 3-4 meters below the surface. Right between two large, potentially dangerous, snow-covered crevasses.

Dirk van As on behalf of Greenland Guidance and GEUS in “Sky Detectives”.

The final expedition to the ice sheet took place in June 2019. A team of 5 including 3 Greenland Guidance mountaineers flew to the dig site armed with shovels and lots of safety equipment. The much desired fan hub fragment was extracted on 30 June.

Central to the investigation was the BEA, the French bureau for investigating civil aviation safety. They got all partners together and working towards retrieving the missing fan hub pieces. Recently, Elephant Productions finished a documentary on the BEA in which the Greenland project gets ample attention. The documentary was made for TV channel France 5, and its French title is Les détectives du ciel. It’s a 87 minute documentary that features Greenland Guidance quite prominently!

A shorter, English version called “Sky Detectives” will be broadcasted internationally. Keep an eye on our @GreenlandGdnc Twitter feed to find out where you can see it.

“Under Ice”, a documentary focussing on the final fan hub recovery expedition, by Arnar Ingi Gunnarsson / Gale Force North.

Sign up to become a 2021 Greenland Guidance field specialist

We are always on the lookout for people with specific skill sets that can help us during future field campaigns. Do you have field experience in Greenland or other remote regions? If you’d like to join us during the 2021 field season (NH spring/summer), then tell us you’re available here: https://greenlandguidance.com/about-us/join-us/. If you’re on the list, we’ll know how to find you.

The team recovering an Airbus A380 engine fan hub from crevassed terrain. Picture by Austin Lines (Polar Research Equipment).

Documentary on the recovery of the airplane engine part

Here’s a very nice 30-minute documentary by talented Arnar Ingi Gunnarsson on the 2019 recovery of the Airbus engine part lost over the Greenland ice sheet. Greenland Guidance was part of the challenging fan hub recovery after a long and difficult search by GEUSONERA – The French Aerospace LabAarhus University and Polar Research Equipment. Recently BEA (Bureau d’Enquêtes et d’Analyses pour la sécurité de l’aviation civile) finished their investigation looking into the causes of the accident – with some interesting findings (check out their website). Greenland Guidance thanks AirbusAir France and Engine Alliance for the excellent collaboration.

Scientific publication about Airbus engine recovery from Greenland

Following our project of recovering a part from an Airbus A380 airplane engine from the Greenland ice sheet last year, we wrote a paper detailing our methods. The part was crucial for determining what went wrong on that flight over Greenland in 2017. Read the paper by Ken Mankoff and coauthors in the Journal of Glaciology here: http://dx.doi.org/10.1017/jog.2020.26.

Abstract:

On 30 September 2017, an Air France Airbus A380-800 suffered a failure of its fourth engine while over Greenland. This failure resulted in the loss of the engine fan hub, fan blades and surrounding structure. An initial search recovered 30 pieces of light debris, but the primary part of interest, a ~220 kg titanium fan hub, was not recovered because it had a different fall trajectory than the light debris, impacted into the ice-sheet’s snow surface, and was quickly covered by drifting snow. Here we describe the methods used for the detection of the fan hub and details of the field campaigns. The search area included two crevasse fields of at least 50 snow-covered crevasses 1 to ~30 m wide with similar snow bridge thicknesses. After 21 months and six campaigns, using airborne synthetic aperture radar, ground-penetrating radar, transient electromagnetics and an autonomous vehicle to survey the crevasse fields, the fan hub was found within ~1 m of a crevasse at a depth of ~3.3 to 4 m and was excavated with shovels, chain saws, an electric winch, sleds and a gasoline heater, by workers using fall-arrest systems.

Airbus engine part recovered from the Greenland ice sheet

In September 2017, an Air France flight traveling west over the Greenland ice sheet experienced a failure in its 4th engine. All on board were unharmed, and the plane landed safely in Goose Bay, Canada. To figure out what exactly went wrong with the engine, a search for the missing engine parts was executed by the Geological Survey of Denmark and Greenland (GEUS) supported by Greenland Guidance.

Minimal camp in a snow-covered crevassed area of the Greenland ice sheet.

The torn-away parts of the airplane engine dropped onto the ice sheet, but the heavy pieces of the fan hub – needed for the investigation – impacted into the snow surface and were lost from sight almost instantly, getting buried further with every subsequent snowfall event high on the ice sheet. The search for the largest and potentially most interesting part was difficult due to severe storms, snow-covered crevasses in the region, and the ever-present risk of polar bears passing by. Guided to a few promising sites by airplane-based radar measurements performed by ONERA (the French aerospace lab), the initial ground-based detection and therefore exact localisation was done by a radar-equipped robot (!) operated by Polar Research Equipment (PRE). The robot was crucial in regions too dangerous for people to tread unsecured, because of crevasses in excess of 10 m wide, yet invisible to the eye due to the snow cover. It wasn’t until the very end of the 3rd field campaign in spring 2019 that a metal detector custom-built by the Aarhus University HydroGeophysics Group clearly detected metal a few meters below the surface.

Video of Airbus A380 fan hub fragment recovery from the Greenland ice sheet 28-30 June 2019.

Greenland Guidance took part in the 4th recovery expedition to the ice sheet, bringing 3 experienced mountaineers from the Icelandic Association for Search and Rescue (ICE-SAR) to the scene. The expedition commenced on 28 June 2019, transporting as many as would fit in an AS350 Air Greenland helicopter (5 people) to the dig site. In spite of all safety precautions (mostly related to digging in a crevassed region), we made good progress. By the end of the second afternoon, we struck titanium. Eager to liberate the part, we kept working until after midnight. But melting the engine part loose and lifting it to the ice sheet surface proved very difficult, as we wanted to avoid contact with the yet-to-be-investigated part as much as possible. On 30 June, after an estimated 20 hours of digging, melting and lifting, the job was done and all returned safely to Narsarsuaq, 100 km southeast of where the engine part had impacted.

Find the GEUS press release here.