Researchers made a note of massive craters found on the Arctic ocean floor, which apparently were formed due to ancient methane explosions.
The craters are somewhere around 12,000 years old, and the gas is still leaking from them. Around 600 gas explosions have been identified to have occurred in the area.
Methane hydrates buried deep in the ocean
This is not the first time such craters have been described, but now researchers know that there are hundreds of unidentified craters that are smaller than 300 meters wide, besides the ones larger than 300 meters that had already been documented.
Researchers argue that the craters contained methane hydrates, formed due to the low temperatures and high pressure of the oceanic floor. The deposits described in the study are located in the Barents Sea, in the Arctic Ocean seafloor, between Norway and Russia. There are over 100 craters, some of them as large as 900 meters wide and 30 meters deep.
Ice sheets consistently covered the hydrates, and the warming of oceanic waters caused the sheets to melt, allowing the methane to expand without reducing the pressure exerted by the ocean and the atmosphere.
Thousands of years went by, and eventually, the hydrates exploded and collapsed, releasing copious amounts of methane gas to the ocean, and then to the atmosphere.
Researchers are not sure about how much methane was released during the explosions, although they theorize that “an area of hydrocarbon reserves twice the size of Russia was directly influenced by ice sheets during past glaciation.”
The findings allow researchers to wonder how will the hydrocarbon reserves in Antarctica and Greenland behave in the future, as there are still submerged methane gas hydrates covered in their ice sheets, meaning that at any point, the methane may cause another sudden explosion.
A potential fossil fuel with worse outcomes for the environment
Methane hydrates are now being seen as a potential future energy source, as they represent a whole new type of fossil fuel. Hydrates form when methane becomes crystallized in the presence of water; high pressures paired with low temperatures provide the ideal environment for these structures to form.
Methane gas is usually produced by microbes in the seafloor, as they metabolize organic matter, such as algae, excrement, and other animals. Researchers believe that only 1 percent of the organic material produced on the surface ends up in the ocean. Now, they realize that Arctic regions are ideal for methane hydrates to form.
It is thought that between 1,000 and 5,000 gigatons of methane hydrate exist buried in the seafloor, although most deposits are deemed inaccessible. Additionally, methane is a greenhouse gas, 20 times more efficient than carbon dioxide. Any large-scale release of methane to the atmosphere is expected to speed up the greenhouse effect.
At first, researchers believed that methane hydrate deposits could only be formed in continental slopes, but the most recent report shows that colder regions are ideal for this purpose. On the other hand, releasing methane to the atmosphere could prove to be a practice that could easily endanger our planet for the sake of using its non-renewable resources.