New research reveals that fire ice, or frozen methane, trapped as a solid under the oceans is at risk of melting due to climate change, potentially releasing large amounts of methane into the atmosphere. I did. Using advanced seismic imaging, the research team found that dissociated methane can travel significant distances, overturning previous assumptions about its stability.
Research shows that ocean fire ice, or frozen methane, is more likely to melt due to climate change and poses a significant threat to methane emissions into the atmosphere.
An international research team led by the University of Newcastle has discovered that when frozen methane and ice melt, the powerful greenhouse gas methane is released and travels from the deepest parts of continental slopes to the edges of underwater shelves. They also found a pocket that had traveled 25 miles (40 kilometers).
Publication in magazine natural earth scienceresearchers say this means more methane could potentially become vulnerable and released into the atmosphere as a result of climate warming.
Methane hydrate: the hidden climate change threat
Methane hydrate, also known as fire ice, is an ice-like structure containing methane buried under the ocean. Huge amounts of methane are stored in the ocean as marine methane. As the ocean warms, it melts, releasing methane, known as dissociated methane, into the ocean and atmosphere, contributing to global warming.
The researchers used advanced three-dimensional seismic imaging techniques to examine sections of hydrate that have dissociated during climate warming off the coast of Mauritania in northwest Africa. They identified specific cases where dissociated methane traveled more than 40 kilometers and was released through underwater depressions known as pockmarks during warm periods in the past.
Researchers at Newcastle University have found that frozen methane trapped on the ocean floor is more likely to melt due to climate change and could be released into the ocean.Credit: Newcastle University
Discovery and its impact
Professor Richard Davies, lead author and Vice-Chancellor for Global and Sustainability at Newcastle University, said: . Our study shows that they formed as methane released from hydrates from the deepest parts of the continental slope spewed into the ocean. Scientists previously thought these hydrates would be less susceptible to climate warming, but it turns out some are more susceptible. ”
Researchers have previously studied how changes in seafloor temperatures near continental margins affect methane release from hydrates. However, these studies mainly focused on regions where only a small fraction of the earth’s methane hydrate exists. This is one of the few studies to investigate methane emissions from the bottom of hydrate stability zones deep underwater. The results show that the methane released from the hydrate stability zone migrated a significant distance towards land.
Broader research perspective and future plans
Professor Christian Berndt, Head of the Ocean Geodynamics Research Unit at GEOMAR in Kiel, Germany, added:
“This is an important finding. Previous research efforts have focused on the shallowest part of the hydrate stability zone, because we thought this was the only part that would be susceptible to climate change.
“New data clearly shows that far greater amounts of methane can be released from ocean hydrates, and a thorough understanding of this fact is needed to better understand the role of hydrates in the climate system. need to be clarified.”
Methane is the second most common anthropogenic greenhouse gas after carbon dioxide (CO2). Methane accounts for about 16% of global greenhouse gas emissions, according to U.S. Environmental Protection Agency figures.
The findings could play an important role in predicting and addressing methane’s impact on a changing climate.
The researchers plan to continue looking for evidence of methane vents along the margin and predict where large methane seeps may occur as the planet warms. Researchers are now planning a scientific expedition to examine the pockmarks more closely and see if they can be more closely linked to past climate warming events.
Reference: “Long-distance transport and emissions of methane from the base of the hydrate stability zone” Richard J. Davies, Jinxiu Yang, Mark T. Ireland, Christian Berndt, Miguel Ángel Morales Maqueda, Mads Huuse, December 6, 2023 , natural earth science.
DOI: 10.1038/s41561-023-01333-w
Source: scitechdaily.com
