Nuuk: Up on the ice sheet

Much of our research in Greenland revolves around the chemistry of water that results from the interaction of water with the bedrock or substrate below the ice. One important control on that resulting chemistry is the initial composition of the water before it makes its way to the base – either as basal melt, englacial (within the ice) melt, or as melt at the surface that makes its way to the base via crevasses.

Our access to a helicopter in Nuuk allowed us for the first time to collect surface melt that ponds in supraglacial lakes and potential is stored at the surface for years before moving to the basal environment.

 

Nuuk

Nuuk, the capital of Greenland, is the home to beautiful fjords filled with icebergs and whales.

It is also within helicopter distance of the icesheet and some large, land-terminating glaciers. In order to sample this drainage of the icesheet, we investigated a couple of glaciers via google earth and settled on the Kangaussarssup Sermia, which terminates in a large braided river valley and ultimately drains into the Ameralik Fjord.

In the helicopter (Air Greenland A-star)

Ameralik Fjord

This location ended up being one of the best sampling sites because the wide, braided channel allowed us to land within 100m of the toe of the glacier and directly access the water as it exits from the subglacial environment.

Unfortunately, while the sampling site was one of the best, the sediment load remained similar to previous sites and we spent long hours filtering samples – although this time from the relative comfort of the hotel bathroom!

 

Kanger – 2

Sarah arrived on August 3^rd ready to head into the field with us and brainstorm other locations that would provide data points of interest. After some long searches and strenuous hikes we found two excellent collection sites that had an obvious singular discharge channel at differing glacial outlets.

In order to save time and accelerate the sample analysis process, we brought our radon detector into the field with us  (radon is an indicator of how long the subglacial water has been in contact with bedrock).

Additionally, we collected a surface sample of the Russell Glacier, which provided us with initial chemical compositions of ice and many photo opportunities.

On a side note, Kangerlussuaq is one of the best places in southern Greenland to have musk ox sightings and we had several chance encounters including one in which we unintentionally chased down a musk ox on our way back to the town of Kangerlussuaq.

As a result of only having a mode of transportation for several days we headed into the field bright and early on the day of our departure (August 5^th) to collect water samples from several kettle lakes scattered around the ice sheet for future carbon and microbe measurements. Many of the lakes we stopped at had highly unusual characteristics (i.e. floating apple like fruit in one of them) which both confused and intrigued us but definitely made us excited to see the data that will come from the lakes.

Kangerlussuaq was the most logistically challenging location we had faced and although we were quite relieved to be leaving that aspect of the region, we were a bit nostalgic about leaving behind the ‘perfect’ sampling sites we had ended up with.

Kangerlussuaq

Carli and Emily arrived in Kangerlussuaq (a former U.S. military base) in the afternoon of the 30^th of July and were reunited with our photojournalist Mindy. We were fortunate enough to have made some contacts with Air Greenland employees and Kangerlussuaq International Science Support (KISS) who helped us gather our equipment (which was being held in cargo) and connected us with someone who was willing to rent us his car later in the week. As we had no mode of transportation for the first several days (and the ice field was located ~45km away from the town center!), we first sampled a glacial drainage tributary that ran through town and into the sea, which was primarily fed by glacial melt (we were assisted by George Roth, a master’s student working with Prof. Sutherland at the University of Oregon, while he waited for his flight back to the U.S. after completing his own fieldwork).

The next day we collected several samples along the length of the channel and made our way to the harbor in order to collect some samples for isotope comparison to the samples we planned on collecting at the margin of the ice sheet.

When we finally secured a truck for our disposal Mindy fearlessly drove us on a very poorly maintained road in search of the ice and we located where a channel coming directly from glacial outflow met the river we had been sampling and collected our first sample of the day there. With malfunctioning filter equipment and a high sediment load, we spent the better half of the day gathering water from this site but were determined to go further in order to collect our first subglacial melt sample in close proximity to the Russell Glacier. When we came around a bend in the road and finally laid our eyes on the terminus of the Russell Glacier and located a sampling site we were pretty happy!

Back at the hostel (late in the evening) we began a long night of processing the bounty we had collected over the course of the day but felt quite rejuvenated because we finally achieved the samples we had initially set out for just in time for Sarah Aciego’s arrival the following day.

Ilulissat Update: the Das Fieldsite

This time, as we sat in the helicopter, we decided not to get too eager until the helicopter had finally left the ground, and thankfully it did! A beautiful 20 min helicopter flight later over the Jakobshaven fjord, and we were met by Sarah Das, colleagues and her team at the spectacular fieldsite – located ~1km from the toe of a sea terminating glacier. As we had arrived at the site several days later than anticipated, we had to collect the same number of samples in a much shorter period of time. Thankfully the WHOI scientists were amenable of our hectic schedule, and willing to drop everything to help us collect our data.

Within one hour of arriving at the fieldsite we began by collecting samples from an active subglacial plume that was visibly moving surface ice, so we quickly got our sampling kit together and headed into one of the boats. The plume location was jammed with icebergs and surface ice but we managed to find a spot that allowed us to collect plume samples at both the surface and at depth. After processing the samples, Sarah took us to the land terminating section of the glacier with promises of finding a prominent subglacial outlet. After climbing steep moraine we made it to a highly pressurized subglacial opening that violently expelled a large volume of zero degree water, we were utterly thrilled to get such a rare and ideal sampling location!  Realizing that the sediment load of the subglacial water was remarkably high, we sent Sarah and her colleagues back to camp as collection time would definitely take several more hours… We toughed it out and managed to filter and collect over 7 liters of water with 8 filter changes, over a span of 3 hours.

 

We returned to camp worn out, cold and wet but were greeted with friendly faces and a warm dinner that was freshly caught by one of the local fisherman. It was a hard day but totally worth it.

The next day we flew back to Ilulissat to be warmly welcomed by Sarah Aciego who’d finally made it to join us for the rest of the Greenland expedition.

Ilulissat Update

We were able to get the ‘friend of a friend’ to take us to three fantastically unique locations: an isolated fjord within the ‘red bay’ (known as such because this location slaughters a large number of whales for meat each year), a sea water sample amidst colossal icebergs, and as close as we could get to the toe of the Jakobshaven Glacier from the Jakobshaven fjord. The whole sea sample expedition took place on a 21ft boat with a 10cm thick fiberglass hull that maneuvered around the enormous icebergs (frequently hitting ones that were human size or less..) at such great speeds that Emily and I frequently thought we had used up all of the fun/adventures people are allowed to have in one lifetime. We returned to the harbor with incredible samples and photos (see below!), and were unscathed except for the colds, chesty coughs and sinus infections that would plague us for many days to follow.

That evening after turning a dire situation upside down and finally collecting some samples we did what we have been craving to do ever since first arriving in Greenland – we rolled in the much fluffier version of dandelions gone to seed as a celebration. Later that night, when we were recovering from our cold and wet but exhilarating journey out to sea, we learned that a miracle had happened and that we had the go-ahead for the helicopter flight to Sarah Das’ (and colleagues’) field site first thing the next morning. Not having accounted for such a sudden departure and having spent the majority of the day collecting samples, we had to organize gear, process samples, pack, and clean like maniacs, getting minimal sleep (only 3hrs!), and find a taxi (another story in itself) in order to make our early morning helicopter ride out to the Das field site. But we couldn’t have been more excited.

 

 

so cold!

with our fearless boat pilot