The first seawater samples are taken onboard the Oden. Around 20 chemical parameters are measured in the water samples to study among other things, the carboncycle and the levels of various gases like methane on this spot.  Many of the analyzes are done onboard.
The first seawater samples are taken onboard the Oden. Around 20 chemical parameters are measured in the water samples to study among other things, the carboncycle and the levels of various gases like methane on this spot. Many of the analyzes are done onboard. Photo: Jorien Vonk


- We are looking for answers as to whether the methane comes from thawing peat bogs as well as land that was flooded at the end of the last ice age, or if it leaks from a deeper source where large natural gas reservoirs below the now thawing permafrost are found, says Örjan Gustafsson, Professor at the Department of Applied Environmental Science, Stockholm University.

Scientists took the first deep water and sediment samples at depths of over 3000 meters in the south-eastern Nansen Basin on 15 July. Sampling takes place above the continental slope to determine if warm water from the Atlantic that circulates at 200-500 m depth destabilizes frozen methane (stored as methane hydrates) along the East Siberian continental slope.

The origin of methane emissions

In previous expeditions to the East Siberian Arctic Ocean, SWERUS-C3 researchers discovered large amounts of old carbon and methane in this area, which is the world's biggest and perhaps most inaccessible of coastal seas. The methane measurements that are being carried out during SWERUS-C3 have two primary aims:

- Our new measurements will deepen our understanding of the findings from previous expeditions and will help pinpoint which part of the huge methane reservoirs in the seabed of the East Siberian Arctic Ocean this methane “bubbles up” from. This is necessary knowledge for predicting how methane emissions may develop in the future, says Örjan Gustafsson.

Bubbles
The first sediment samples are secured on the icebreaker Oden from 3100 meters deep. Photo: Jorien Vonk


SWERUS-C3 will revisit a number of the methane “bubble-fields” to further study how these have changed over the past years. The expedition will also secure sediment cores that can shed light on how old carbon is released from thawing permafrost over time - from a thousand years down to a few years ago.

Unique expedition

The expedition's overarching research question concerns the relationship between climate, cryosphere (such as permafrost and sea ice) and carbon - hence the acronym C3 (Climate, Cryosphere, Carbon). SWERUS-C3 will operate in two stages or “legs.” The first leg, which is led by Örjan Gustafsson, has the theme "From thawing permafrost to the emission of greenhouse gases". The second leg, which is led by Martin Jakobsson at the Department of Geological Sciences, Stockholm University, has the theme "From the warmer oceans and shrinking sea ice to greenhouse gases.” The change-over of crew and scientists will take place in Barrow, Alaska, on 20 August.

- This is a unique expedition in many ways. Researchers from 14 different nations are using advanced sampling and measuring instruments on board the icebreaker Oden. It is a fantastic opportunity for Swedish researchers to contribute to one of the hottest research areas in international climate research, says Örjan Gustafsson.

Quick Facts about SWERUS-C3

The international research expedition SWERUS-C3 is a Swedish-Russian-American collaboration led by researchers at Stockholm University. There are in total 84 (19 women and 65 men) participating researchers from 14 different countries. Most of the participants come from Sweden, Russia, USA and Germany. Other countries with participants on board are Canada, United Kingdom, Estonia, Greece, Italy, Poland, Portugal, Spain, Switzerland and the Netherlands.

Oden's crew consists of 24 members per leg.

The icebreaker Oden will cover approximately 7,000 nautical mil = approx. 13,000 km (first leg = 3100Nm and second leg = 3900 Nm) in almost 100 days.

SWERUS-C3 was made possible thanks to a grant from the Knut and Alice Wallenberg Foundation and logistical support from the Swedish Polar Research Secretariat.

Learn more about SWERUS-C3

Expedition website: www.su.se/swerusc3
Polar Research Secretariat website:  www.polar.se/expedition/swerus-c3
University of Gothenburg's website: www.science.gu.se

Follow SWERUS-C3 on Twitter, @SWERUSC3 and Facebook, www.facebook/swerusc3