How do chemical processes in the ocean work and how do they change when the climate warms? This question is being investigated by Prof. Dr. Christian März's Environmental Geology working group at the Institute of Geosciences at the University of Bonn. And not only in the laboratory, but also in the field. More precisely: in the Arctic, in the south-east of Greenland. In a six-week expedition on the research icebreaker RRS Sir David Attenborough, doctoral student Katrin Wagner and an interdisciplinary team of 40 researchers and staff from renowned research institutes around the world are investigating traces of glacier changes in Greenland and life in the coastal waters on the edge of the world's largest island as part of the KANG-GLAC project. Wagner's task: to extract sediment cores from the seabed and take samples that can later be analyzed in the laboratory in Bonn. “With the samples we take, we can determine the current geochemical processes in the seabed and learn a lot about the interactions between glacier activity and marine environmental conditions. At the same time, we collect evidence of how these may have changed over time,” says Katrin Wagner.
Living and working on board a research vessel
Anyone who has always wanted to know what it's like to work and conduct scientific research on board a research vessel now has the chance to find out. During the expedition, PhD student Katrin Wagner will be answering questions from members of the public on the university's Instagram account (@universitaetbonn) and on the university's website. Curious people can send their questions to wissenschaftskommunikation@uni-bonn.de.
Expedition to the Arctic
The Greenland Ice Sheet is decaying at an accelerating rate in response to climate change. Warm Atlantic waters moving through fjords eventually meet the ice fronts of marine-terminating glaciers, increasing melting and causing icebergs to break off. In turn, the injection of increased fresh meltwater into the ocean is altering both ocean currents and marine ecosystems around Greenland and farther afield in the North Atlantic, with potential effects on UK weather systems.
Looking back for a better outlook
The KANG-GLAC project aims to determine the intricate processes driving these changes by studying what is happening now and during warm climatic periods in the past. Researchers can help anticipate future ice-ocean-marine ecosystem changes by extending the modern observational record back through the last 11,700 years, a period known as the Holocene. This includes a time when summer temperatures in Greenland were 3-5°C warmer than today: the Holocene Thermal Maximum. While some records of 20th-century iceberg calving and warm water inflows exist around Greenland, records of how glaciers then decay and the effects on marine productivity over many decades to millennia are lacking. Dr Kelly Hogan, a marine geophysicist from British Antarctic Survey is Co-lead on the project. She says: “Our expedition is extremely timely as we are seeing every day in the news how the Arctic is changing, and we know there will be knock-on effects for the rest of the planet. We need to understand how the Greenland Ice Sheet is likely to decay over the coming decades to centuries, and what the subsequent effects will be on both ocean currents and marine food webs. This is now urgent information for us to gather so policymakers can understand what will happen in the North Atlantic and set out appropriate adaptation and mitigation plans.”
With underwater robots and drill cores
This three-and-a-half year project will generate records of glacier, ocean, and ecosystem change for the Holocene era at key sites close to Kangerlussuaq Fjord in SE Greenland. The team includes a mix of researchers – including oceanographers, biologists and geologists – who will collectively use a range of instruments to retrieve samples from rocks on land, from the ocean, and from the seafloor to gain a comprehensive picture of this region and its current and potential future response to environmental change.
Using state-of-the-art capabilities of the RRS Sir David Attenborough and deploying advanced underwater robotics such as the Gavia, operated by the Scottish Association for Marine Science (SAMS), the team will investigate modern interactions between meltwater expelled from glaciers and the inflowing warm ocean waters, as well as how this affects primary productivity in Greenland’s fjords and coastal seas.
In parallel, marine sediment cores from the seafloor and terrestrial rock samples collected using helicopters deployed from the ship will reveal changes in glacier size, ocean temperatures, and carbon storage at the seafloor all changed during the Holocene. Professor Colm O’Cofaigh, a glacial and marine geologist from the Department of Geography, Durham University, is Co-Lead PI on the project. He says: “Understanding the Holocene record of Greenland Ice Sheet change and the role of the ocean thereon is crucial for placing current observations of ice and ocean change into their longer-term context and for underpinning predictions of future change. The range of tools to be deployed from the RRS Sir David Attenborough during the KANG-GLAC cruise provides an unprecedented opportunity to assess this change over the last 11,700 years.”