The Boreal Forest: A journey through natural gas

The southern part of the Boreal forest is full of rings. No, not fairy rings or golden rings, nor Lord of the Rings… the southern part of the Boreal forest is full of natural gas rings. These rings are called forest rings.
The forest rings are light-coloured circular features that range up to 1.6 kilometres in diameter. The rings are visible on air photographs, satellite images, and from aircrafts. At the edge of the forest ring, where tree growth is stunted and poorly forested, there is a topographic depression that is filled with peat. There are also gases, such as hydrogen sulfide and methane (e.g., natural gas), in the sands and gravel left behind by glaciers. The gases are released into the groundwater and the air above the land. The boreal forest is, to put it in human terms, “passing gas” — natural gas.
In Ontario, there is a link between the geology of the land and the forest rings. You will find an abundant amount of rings in areas where the soil beneath the forest is made of clay.
The clay marks the bottom of an ancient ocean that once covered the land when the last of the glaciers melted about 10,000 years ago.
There are complex explanations to account for the formation of the forest rings. Stewart Hamilton of the Ontario Geological Survey is recognized because of his work on this topic.
The rings tell a story about the earth and the way the rocks, soils, groundwater, minerals, and bacteria (e.g., tiny bugs) come together to create the natural gas that affects life forms in, and on, the soil. Once created in the earth, the natural gas moves up through the soils left by glaciers into the groundwater and leaks into the atmosphere. There are no drills required. The gas passes quietly into the air.
Forest rings are certainly interesting from a geological perspective, but you may wonder what their importance is to life and humans. Natural gas is necessary for the formation of forest rings and also helps determine the types of vegetation that grow in and around it.
Little research has been done on the subject. However some believe that forest rings may be a source of natural gas that will help remote communities move away from using diesel to generate electricity.
There are many forest rings in the southern region of the Far North, but does this mean there is a lot of natural gas? There is definitely natural gas passing into the air, but it is hard to determine exactly how much. Could this be a local source of energy for communities? How would we capture it? Again, more research would need to be undertaken before these answers can be determined. However, it does present an interesting option for alternative fuel sources.
A rough calculation based on data from one ring indicates that over the past eight years, enough natural gas has been produced to sustain the electricity needs of one house for about six months. This may not sound like a lot, but there are thousands of forest rings in the southern part of the Boreal forest.
Although many questions remain unanswered, this is certainly an interesting geological process and is something to think about the next time you go for a walk through the southern Boreal forest.
Understanding the “Ontario beneath our feet” is fundamental to Ontario’s economy and quality of life.