The Siljan Ring in Dalarna, Sweden, is the result of a meteor impact that occurred 377 million years ago and has a diameter of 100 km. Lakes Siljan, Orsasjön, and Oresjön are all situated within this crater.

Methane emission measurements have been carried out on these lakes using specialized equipment, such as trace gas measurement and floating chamber techniques. The study was conducted by Professor Johan Mellqvist and Dr. Vladimir Conde, both of whom are affiliated with the Department of Space, Earth, and Environment at the Chalmers University of Technology in Gothenburg.

Methane is often formed at the bottom of lakes where there are large amounts of biological waste materials in the form of sediment, combined with stagnant water, typically resulting in non-distinct leakage of smaller amounts of methane. According to Mellqvist, what makes the findings at the Siljan Ring unusual is the discovery of distinct spots with significant emissions, resulting in large plumes of methane released into the air. This occurs despite the absence of sediment on the seabed and the presence of moving water.

It is therefore reasonable to assume that the methane does not originate from the lake itself but has been formed beneath it, possibly as a result of bacterial activity deep within the Earth, as suggested in other studies.

More research is needed to understand the complete size of emissions and the possible impact they may have on climate change, but there is no doubt that the lakes in the Siljan Ring area are different in this respect from other lakes in Sweden.  

The results can be found in the report "Mätning av naturliga metanläckage från sjöar i Siljansringen" ("Measurements of natural methane emissions from lakes in the Siljan Ring area").

• The fact that there are carbohydrates below the bedrock under Lake Siljan has been known for centuries. There are examples of farms that have used natural gas found on their own land to heat their homes.
• What has not been known so far is the extent of these emissions, and whether and how much they contribute to climate change.
• Methane released into the atmosphere is a green house gas 28 times [1] more potent than carbon dioxide. To reduce natural methane emissions thus must be considered as a priority from a climate protective point of view.
• Igrene has access to technology that makes it possible to convert methane produced from subsurface reservoirs into hydrogen and carbon, before the methane reaches the surface of the earth and is released in the atmosphere. The process is called pyrolysis and avoids generation of carbon dioxide.
• In this way, Igrene is able to contribute both to reducing naturally occurring methane emissions and is able to offer products that can contribute to the conversion into a fossil free economy.

Contact person:

Mats Budh, mats.budh@igrene.se+46 706 50 62 26

About Igrene:

AB Igrene has previously explored for hydrocarbons in the Siljan Ring area. The Company is listed on the Spotlight Stockmarket exchange and has some 3 000 shareholders. Igrene has discovered natural gas in several places around Lake Siljan. A large number of exploratory wells have been drilled, and in several of these wells powerful flows of very pure methane have been found. These wells have been temporarily sealed off. The Company aims to convert the methane in these wells into carbon and hydrogen without generation of carbon dioxide using a pyrolytic technology developed by Norwegian company SEID AS (ColdSpark®).

See also:  www.igrene.se,  www.seid.no

[1] Swedish Environmental Protection Agency: "Methane (CH4) is a much more potent green house gas than carbon dioxide (CO2)  in the short term, but in the atmosphere, it is dissolved more quickly. Seen over a 100 year period, CH4 is 28 times more potent than CO2. But over a shorter time period, the effect is much greater."