The NERC-funded Lakes and the Arctic Carbon Cycle (LAC) project draws to a close this month and so the team met in the New Forest to work on finalising the datasets and paper writing. The focus of this meeting was interpreting the Holocene sediment record from Ruppert Lake in Alaska. The extensive suite of proxies analysed on this sediment core includes pollen and plant macrofossils to detect shifts in terrestrial vegetation and remains produced within the lake including geochemical elements, stable isotopes analysed on the organic fraction of sediment, chlorophyll and carotenoid pigments and diatoms. The results arising from the project indicate that terrestrial vegetation shifts have a clear effect on the structure and function of lake ecosystems, indicating that Arctic “greening” has the potential to substantially modify net carbon fluxes between the lake and catchment, with implications of for terrestrial carbon budgets on the landscape scale.
We presented research from the LAC project and from Disko Island at two conferences in Asia this summer. The INQUA conference in Japan (26th July to 2nd August) was held in Nagoya and is held every four years for researchers who study the Quaternary time period (divided into the Pleistocene and Holocene). Suzanne McGowan presented her pigment results from multiple Arctic lakes in northern Norway, Alaska and Greenland, while Pete Langdon presented a poster on the LAC project as well as convening a special session on ‘Tipping points in the late Quaternary’. Mark Stevenson presented his PhD research on Arctic Lakes in Disko Island, west Greenland which included pigment and carbon isotope results. Everyone who attended was in agreement that the INQUA congress was very comprehensive and a great opportunity to networking. Highlighting the importance of this conference to Japan, the emperor and empress of Japan were in attendance at the opening ceremony!
We then made the 3,000km journey (two or three consecutive flights) to Lanzhou in the central interior of China. Here we attended the IPS (International Paleolimnology Symposium) at Lanzhou, China (4th to 7th August). The hospitality offered by the organising committee was very generous and the conference was again a great place to network. We were joined by Maarten van Hardenbroek who gave an excellent presentation on the Alaskan elements of the LAC project and John Anderson who convened a session and spoke enthusiastically on Nitrogen dynamics, which included many references to carbon cycling. The audience were impressed by the detail of the changes that linked to the tree-line advance. Suzanne McGowan in her keynote outlined the importance of ‘ecology’ within palaeo reconstructions, and Mark Stevenson gave his talk on carbon cycling in Disko Island lakes to the west of Greenland. Pete Langdon presented the LAC poster which sparked many hours of discussion and debate and presented an enthusiastic talk on using salmon populations to reconstruct changes in the Atlantic over the past 2,000 years.
We really enjoyed the conferences and are now going into the final stages of the project. As the data rolls in our understanding of the importance of Arctic lakes in the global carbon cycle increases!
Suzanne McGowan at INQUA presenting on carbon cycling using pigments in Arctic lake sediments
Pete Langdon at INQUA presenting the LAC poster
Silhouette of Mark Stevenson at IPS presenting on reconstructing carbon cycling using Dikso Island lake sediments, West Greenland
Earlier in December I spent some time at Newcastle University continuing the lipid biomarker analysis, which is part of my project. Lipid biomarker analysis should allow me to gain more information about terrestrial (land), aquatic (in-lake) and microbial changes in the sediment cores from Disko Island, West Greenland.
Here I am next to the microwave digester which heats the sediments up in solvents to extract the lipids.
This photograph displays the finished ‘acid’ extracts and the drying down cabinet used to evaporate solvents and leave only the extracts in the test tubes.
I’m pleased the labwork earlier in December went so well and plan to return to Newcastle to complete the procedure next week.
Happy New Year,
After returning from Blæsedalen we had a couple of days of cloudy damp weather so we used the time to explore the local area and recover from mosquito bites, waiting for the weather to improve.
Through the fog and mist we managed to spot a Fin whale in the Disko Bay near the Arktisk Station. Fin whale, the second largest whale species, are an endangered species, so it was an amazing sight.
We walked along the black basalt beach which is so dark as the upper layers of rocks on Dikso Island are primarily volcanic. Mark could not resist picking up a lump of iceberg! This ice will have likely been deposited as snow possibly hundreds, or even thousands of years on the Greenland ice sheet. It most probably entered the sea in the Ilulissat Ice fjord 100km to the East of Disko Bay.
Image of the stations research vessel Porsild in the Qeqertarsuaq harbour. The weather cleared up on Wednesday and the rough sea became much calmer so with the station logistics leader Akaaraq we went by speed boat west around the coast to the bay Laksebugt.
The journey was very exciting and fast with such a powerful speedboat. We saw many ice burgs and were joined by Tim from Durham University and Kathryn who is based at Queen Mary in the University of London. When I was here in April Tim and Kathryn were also visiting Artksik station so it is amazing that they have chosen to return at the same time. Tim and Kathryn are researching the seasonal variations in Glacial Geomorphology here on Disko Island. You can find out more about their work here.
We reached Laksebugt after about 45 minutes on the boat and promptly set off for the lake, which is at about 350m above sea level through quite boggy terrain. It was well worth the hike though, because, despite the persistent mosquitos, the lake was beautiful and we were lucky enough to have blue skies for much of the day. The fieldwork went well and all samples were collected without incident over the course of around 5 hours before we began the hike by down to the beach. The views on the decent were fantastic (see below).
We have returned from four days of fieldwork visiting two lakes in the Blæsedalen valley (in Greenlandic, Itinneq Kangilleq) here on Dikso Island. The hiking was very tough as the terrain is very hummocky, requiring passage through boulders, cobbles, bog, moss and shrubs while carrying our provisions and field equipment. To get to our base camp near the first lake took about 9 hours of hiking, but the continuous 24 hour light here in the Arctic meant there was no rush for dusk.Image of the Blæsedalen valley on the first day. Low cloud covered the valley, but visibility was sufficient although the peaks of the valley walls could not be seen.
The lake is approximately 1km wide and is surrounded by a mossy, guano rich bog. Disko 1 lies in the central part of the Blæsedalen valley at an altitude of approximately 388 meters. An example of the terrain and small ponds surrounding lake Disko 1.
An attack by mosquitoes at lake Disko 1. Despite covering myself in Jungle Formula DEET, ‘Mosiguard’ and homemade citronella extract repellent I still got no fewer than 15 bites. Joe was not on the mosquitoes menu and only got a couple of bites!
Water sampling at lake Disko 1. We took lake water samples for nutrient analysis back in the lab and filtered lake water for lipid and pigment source studies. We also measured dissolved oxygen, temperature, conductivity and pH using a YSI probe that was calibrated in the field.
On the third day we hiked for about three hours to lake Disko 2 which lies in a glacially scoured basin with steep head walls at either side. Here, at an altitude of 630 meters the vegetation is sparse and the soil is poorly developed in many places. Freeze-thawing is a key action responsible for weathering the basaltic cliffs and is responsible for mounds boulders surrounding the lake.
After the limnology was completed we took soil and plant samples from the surrounding catchment and estimated plant coverage using quadrats at sites in a transect from the lake basin. We decided due to the terrain that it was better to return to our base near Disko 1 to spend the night.
We are now rested after a day to catch up on sleep and have eaten lots of Greenlandic produce to boost our energy levels. Tomorrow we will take a motor boat sailed by Akaaraq in a westerly direction around the coast from Qeqertarsuaq to a beach at Laksebugt (Itilleq) from where we will hike across Iparaatsi to lake Disko 4 and repeat our water sampling and vegetation surveys.
From Ilulissat, we boarded the Disko Line ferry bright (sort of) and early at 6:30 am yesterday (30th) morning before setting off at 7. The route took 4 and a half hours and, while it was chilly, we were really rather fortunate with the weather and we even got a sunny interval or two! We, unlike most of our fellow passengers, managed to remain on deck for the vast majority of the journey. There was of course good reason for this; we were amongst an iceberg dominated landscape across Disko Bay before approaching the island where mountains began to tower ahead.
We arrived into the harbour at Disko Island (known as Qeqertarsuaq in Greenlandic) at 11:30 and were picked up by Ole, the logistics manager at the University of Copenhagen’s Arktisk Station, where we shall be staying until the 9th August (except when we’re camping out in the field). The station is about a kilometre from the harbour and just outside the small town. Ole took us for tea in the library where we remained for some time and chatted about the station, the research project, and many other things.
After tea, we joined everyone for an amazing seafood buffet prepared for some very special visitors to the station. It was here that we were able to meet many of the other postgraduate researchers currently staying at the station. A short walk into town (via the puppies!) followed lunch and we bought some provisions for the days ahead. On returning to the station, we were shown our room by Arktisk Station’s manager, Akaaraq. The room is superb and has fantastic views out into Disko Bay where the icebergs slowly float by our window. In the evening, we went on a short walk around the town before returning station for some rest.
Today (the 31st), we have remained in the station where, after a small lie-in, we have spent much time preparing for the fieldwork and camping ahead. It’s just as well that our fieldwork is not starting today because the weather is somewhat wet and gloomy! Let’s hope that it improves for the days ahead.
Joe & Mark.
In April 2013, with a group of EU Interact funded researchers, Suzanne McGowan, Emma Pearson and Erika Hogan, I was part of a team that collected sediment cores from three ice covered lakes on Disko Island to reconstruct past climate and carbon cycling over the Holocene (~10,700 years). Now, with Joseph Bailey, a graduate student also at the University of Nottingham we set out to revisit Disko Island. This has been made possible by a travel grant from NERC, provided through an application to my university’s doctoral training centre travel award committee. Our intention is to collect samples of soils and plants from the same lakes, which should help to calibrate the lipid and pigment analyses proposed to be completed on the sediment cores. Visiting the lakes during the ice-free summer will also make geomorphology and vegetation surveys possible.
The journey to Disko Island, West Greenland is long and complex. We both set out on Friday from Nottingham accompanied by many heavy bags full of our equipment and camping food! From Manchester we flew to Copenhagen, had a day of sightseeing and then took an early morning flight to Kangerlussuaq, which is an ex-air base and is now the main transit point for international flights between Denmark and Greenland. After a couple of hours wait, we flew by a Dash 8 turboprop to Ilulissat where we are now waiting for the twice weekly, summer only ‘Diskoline’ ferry to Qeqertarsuaq. Today, during our wait for the ferry we have been admiring the beauty of the stunning Ilulissat Ice Fjord, known as Kangia in Greenlandic, which was made a UNESCO world heritage site in 2004. The Ilulissat Ice stream (Sermeq Kujalleq), which feeds the fjord, is the most active in West Greenland. As we traversed the granite and quartz across the undulating, rugged, rocky terrain, we caught glimpses through an awe inspiring fog of ice bergs floating down the fjord bound for the Disko Bay. Tomorrow we will take a Disko line ferry from the northern at Ilulissat for the four hour crossing to Qeqertarsuaq and Arktisk Station, part of the University of Copenhagen, which will be our base for the next 9 days.
Mark and Joe
Photos of the Ilulissat Ice Fjord, a UNESCO world heritage site which we visited while waiting for the Diskoline ferry to Disko Island
Last few days in Sisimiut and we’re clearing up a few loose ends. The cores were packed up and shipped to the UK.
We also had a few things to clear up from our previous project. For the past few years we have been monitoring nitrogen deposition across the region as part of the NERC-funded project. This project is coming to an end, so we needed to collect in our resin samplers. So, John & James headed back to Kangerlussuaq to collect the samplers in that area- here’s what the resin tubes look like.
They are fairly large collectors to dismantle and there are five located around each lake.
Suzanne took down the samplers at lake AT5, a site close to Sisimiut with the help of Avatannguaq, Søren and a sledge.
A windy day, but beautiful skies looking out towards the sea
One of the big problems we encountered during this trip is that there has been very little snow this Spring in Sisimiut.
We were very fortunate that there were a few days of heavy snowfall around the time that we arrived, which meant we could drive snowmobiles from the town to access some of the lake sites that we wanted to (AT1 and AT2). However, one of our target sites, AT7 proved completely inaccessible either by snowmobile (too little snow on the low ground) or by foot (too much snow up high).
We tried to core an alternative site up in the mountains (AT3), but at 24m deep, this lake was a little deeper than we really wanted for the project and at the limits of what our coring gear could handle. We took some exploratory cores, but they were not promising, possibly because we could not access the deeper depositional part of the basin.
Here is the team taking the exploratory Russian core on lake AT3.
So we decided to stick to the original plan, and will now core lake AT7 in the summer.
On a more positive note though, we did successfully core two lakes, taking Holocene sequences (over 2m long) using a Russian corer and using a short kajak corer to retrieve the upper less consolidated sediments.
Here are the parts of the Russian corer- the rods are assembled together as it is lowered down and the barrel cuts out a semi-circular sediment core when it is turned.
This is what the mud looks like when it comes up.
There are some grey bands of clay-like material that probably represent periods of past catchment erosion. It is possible to make out layers in the sediment, showing that it is preserving the record of change in this region very well, with minimal mixing.
Here John & James are taking a short kajak core to sample the upper sediments. James drew the short straw and ended up being the one who had to put his hand under the water to bung the bottom of the core when it came up.
But he was clearly very proud of the results.
Here we are arriving back at the edge of the town, where the huskies live with our haul of mud.