An Arctic methane explosion that took place close to 12,000 years ago resulted in several large craters at the bottom of the ocean, a new study has discovered. But what stands out as interesting is the fact that thousands of years later, gas is still seeping out slowly from the seafloor.
The study published earlier this week in the journal Science details yet another set of findings regarding these explosions that took place over the past thousands of years. And with climate change very much a hot-button topic these days, scientists are wondering whether it’s possible that these Arctic methane explosions may take place in the future, and how they could play a part in global warming, according to the Washington Post.
Researchers involved in the new study are especially concerned, as methane was found to be leaking “profusely” from the craters. As Phys.org explained, methane is a so-called “greenhouse gas” that has been cited as one of the leading drivers of climate change.
“The crater area was covered by a thick ice sheet during the last ice age, much as West Antarctica is today,” said study first author Karin Andreassen of the CAGE Center for Arctic Gas Hydrate, Environment, and Climate.
“As climate warmed, and the ice sheet collapsed, enormous amounts of methane were abruptly released. This created massive craters that are still actively seeping methane “
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Andreassen said that there were over 600 gas flares spotted in and around the craters, still active long after the original Arctic methane explosion. She added that the amount of gas being spewed out in present times is “nothing” in comparison to the methane released right after the deglaciation period that followed the last Ice Age.
The connection between methane release and climate change has been well-documented for years. A fact sheet from the Environmental Defense Fund notes that methane is 84 times more potent than its fellow greenhouse gas carbon dioxide in the short-term, making it a clear and present threat when it absorbs the heat of the sun, contributing to global warming. It doesn’t linger as long in Earth’s atmosphere as CO2 does, but its short-term effects, meaning its effects in the first two decades after it gets released, are much more dangerous. As such, the EDF believes that methane and carbon dioxide emissions are both a key concern when it comes to addressing climate change.
According to the Washington Post, methane’s longer-term effects are similarly deadlier than those of CO2, as the gas could have 30 times stronger warming effect over the first 100 years from the time it is first released.
Although some of the craters were first seen as far back as the 1990s, the researchers used newer forms of technology in their study, discovering that the Arctic methane explosion created much larger craters over a wider range than initially believed. Craters found on the Siberian peninsulas of Yamal and Gydan only measure about 170 to 300 feet wide and are dwarfed by the ones found by Andreassen and her team, which include some that are 3,000 feet wide and almost 100 feet deep.
All in all, there are more than 100 craters found on the seafloor of the Barents Sea, an Arctic region that stretches from Norway to Russia.
How exactly did such an event happen? Phys.org wrote that the Arctic ocean floor is rich in methane trapped in hydrates, or solidified mixtures of gas and water. These are stable structures under high water pressure and cold temperatures, making them conducive to the frigid Arctic weather. But back when the Arctic methane explosion in question took place, the hydrates built up in mounds and began to melt, while being so over-pressured that they ultimately collapsed and released methane into the water column.
These events, said study first author Andreassen, seem to be rare enough not to cause concern. At this point, it still has to be determined whether the fantastic gas release caused by the explosion 12,000 years ago could have resulted in the gas reaching the atmosphere, or whether there is a chance that these events could happen in the near future. But as the Washington Post wrote, citing a separate paper authored by Natural Resources Canada climate scientist Stephen Grasby, a future Arctic methane explosion of similar magnitude could result in a massive uptick in global warming, as well as a “climate feedback loop,” or a vicious cycle of sorts where even more methane is spewed out into the atmosphere.
[Featured Image by John McConnico/AP Images]