2023-12-07 12:13:12
MADRID, 7 Dic. (EUROPA PRESS) –
A new study has shown that the frozen methane trapped as a solid beneath the oceans It is vulnerable to melting due to global warming and can be released into the sea.
An international team of researchers led by the University of Newcastle (United Kingdom) has discovered that, as frozen ice and methane melt, it is released and moves from the deepest parts of the continental slope to the edge of the submarine shelf.
They even discovered a bag that had moved 40 kilometers. As published in the magazine ‘Nature Geoscience’This means that, as a result of a warming climate, much more methane, a powerful greenhouse gas, could be released into the atmosphere.
Methane hydrate, also known as ‘fire ice’, is an ice-like structure found buried at the bottom of the ocean that contains methane. Large amounts of methane are stored as marine methane beneath the oceans. It thaws when the oceans warm, releasing methane into the oceans and atmosphere – known as dissociated methane -, which contributes to global warming.
Scientists used advanced three-dimensional seismic imaging techniques to examine the part of the hydrate that dissociated during climate warming off the coast of Mauritania, northwest Africa. They identified a specific case in which the dissociated methane migrated more than 40 kilometers and was released through a field of underwater depressions, known as pockmarks, during past warm periods.
Lead author Professor Richard Davies, Pro-Vice-Chancellor, Global and Sustainability, at the University of Newcastle, said in a statement: “This was a Covid lockdown discovery. I reviewed images of strata just below the modern seafloor in front of the coasts of Mauritania and stumbled upon more or less 23 pockmarks — remember it’s a statement–. Our work shows that they formed because the methane released by the hydrate, from the deepest parts of the continental slope, emptied into the ocean. Until now, scientists thought that this hydrate was not vulnerable to climate warming, but we have shown that part of it is.”
Researchers have previously studied how changes in bottom water temperature near continental margins can affect the release of methane from hydrates. However, these studies focused mainly on areas where only a small part of the world’s methane hydrates are located. This is one of the few that investigate the release of methane from the base of the hydrate stability zone, which is located deeper underwater. The results show that methane released from the hydrate stability zone traveled a significant distance toward land.
Professor Christian Berndt, Head of the Marine Geodynamics Research Unit at GEOMAR, Kiel, Germany, highlights that “this is an important discovery. Until now, research efforts have focused on the shallower parts of the hydrate stability, because we thought that only this portion was sensitive to climatic variations.
“The new data clearly shows that much larger volumes of methane can be released from marine hydrates and we really need to get to the bottom of this to better understand the role of hydrates in the climate system,” he adds.
Methane is the second most abundant anthropogenic greenhouse gas after carbon dioxide (CO2). According to data from the United States Environmental Protection Agency, it represents around 16% of global greenhouse gas emissions.
Thus, the results of the study can play a key role in helping to predict and address the impact of methane on our changing climate.
The team plans to continue looking for signs of methane vents along the margin and try to predict where massive methane leaks are likely to occur as we warm the planet. Researchers now plan scientific cruise to drill into pockmarks and see if they can link them more closely to past warming climate events.
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