Methane emissions from the deep ocean responsible for climate change: Newcastle University

The frozen methane known as "fire-ice" is susceptible to melting as a result of climate change and may end up spilling into the ocean

Researchers from Newcastle University have produced a new study that demonstrates how vulnerable fire-ice—frozen methane sealed as a solid underneath our oceans—is to melting as a result of climate change and potentially spilling into the ocean.

According to this study published in the journal Nature Geoscience, this suggests that as a result of climate change, a lot more methane may be vulnerable and released into the atmosphere.

The methane-containing ice-like structure called methane hydrate, or fire-ice, is buried beneath the ocean floor. Under the oceans, marine methane stores enormous volumes of methane. Dissociated methane, which is released into the atmosphere and oceans when the oceans warm, causes it to thaw and contributes to global warming.

The scientists examined the piece of the hydrate that dissociated during climatic warming off the coast of Mauritania in Northwest Africa using sophisticated three-dimensional seismic imaging techniques. They pinpointed a particular instance in which, during previous warm periods, dissociated methane traveled almost 40 km and was released through a field of underwater depressions known as pockmarks.

Leading author Professor Richard Davies, Pro-Vice-Chancellor, Global and Sustainability, Newcastle University, stated, "It was a Covid lockdown discovery; I pretty much stumbled over 23 pockmarks when I revisited imaging of strata just under the modern seafloor offshore of Mauritania. According to our research, they originated as a result of methane spewing out of hydrate and venting into the ocean from the lowest points of the continental slope. It was previously believed by scientists that this hydrate was not susceptible to climate change, but our findings indicate that a portion of it is.”

After carbon dioxide (CO2), methane is the second most prevalent anthropogenic greenhouse gas. According to data from the US Environmental Protection Agency, methane makes up roughly 16% of greenhouse gas emissions worldwide.

The findings of this study may be very helpful in predicting and mitigating the effects of methane on our changing climate. As the earth warms, the team intends to keep looking for signs of methane vents along the margin and attempting to forecast the locations of major methane seeps. To dig deeper into the pockmarks and try to establish a stronger connection between them and previous instances of global warming, the researchers are currently organising a scientific cruise.