German and Swiss scientists claim that methane trapped undersea can be released in the atmosphere due to seismic activity. The study was released in the latest issue of the journal Nature Geoscience and reveals that if the methane reservoirs are opened, it could have devastating impact on the world’s future climate.
Methane is one of the most dangerous greenhouse gases, as it is nearly 25 times more effective than carbon dioxide in trapping solar heat. Besides being introduced to the environment as a consequence from burning of fossil fuels, the gas could also be induced as a result of volcanic eruptions.
Looking for evidence, the team analysed sediments from the bed of the northern Arabian Sea. They found that methane is stored in the cores in the form of methane hydrates, only 1.6 meters under the sea floor.
The scientists looked at historical earthquake data from the region and established that an earthquake, which occurred in the region in the 1940s caused fracturing of the ocean sediments. This has led to a release of methane that was trapped below the hydrates.
In their paper, the team refers to the 8.1-magnitude earthquake as the biggest event detected in the Arabian Sea. It resulted into rupturing of a methane reservoir at a point known as Nascent Ridge and consequently releasing 7.4 million cubic meters of the gas over a few decades. The team emphasized that it is very likely that other locations in a close proximity to the epicenter of the earthquake could have been affected.
On a slightly different note, another study published in Nature earlier last week, used computer models to estimate the costs associated with release of methane in the atmosphere from melting permafrost. The scientists looked into reserves in the Arctic, calculating that if melting occurs at even one of the locations in the region known to be a methane reserve, it would cost a staggering $60 trillion (£40tn).
