ALASKA-Big Trail Lake is a thermokarst lake, which signifies it formed due to permafrost thaw. Permafrost is terrain that remains frozen all year; the permafrost in inner Alaska features large wedges of actual ice locked within the frozen Earth. When the glaciers melt, the Earth's surface collapses, forming a sinkhole that can overflow with water. As an outcome, a thermokarst lake forms.
"This lake did not exist 50 years ago," said Katey Walter Anthony, an ecologist at the University of Alaska-Fairbanks, in a statement released by NASA. "Three years ago, the earth was around three meters higher, and there was a spruce forest."
"Lakes like Big Trail are new, they're young, and they're vital because these lakes are the future," Walter Anthony noted.
As the permafrost surface underneath lakes thaws, several incidents occur: microbial activity increases and pathways emerge in the permafrost. Microbes consume plant residues and other organic compounds in the previously frozen ground at Big Trail Lake and other thermokarst lakes in the Arctic, releasing carbon dioxide and methane. Occasionally, permafrost melting can build 'chimneys' underneath lakes, allowing previously confined methane and other gasses to emerge.
This 'geologic' methane leak is unfolding at Esieh Lake, another of Katey Walter Anthony's ABoVE study locations. The gasses ascend to the lake's surface and are emitted into the atmosphere in all thermokarst lakes.
The Arctic-Boreal Vulnerability Experiment (ABoVE) is a NASA Terrestrial Ecology Program field campaign in Alaska and Western Canada. ABoVE is huge research into environmental changes and their impacts on social-ecological systems, as declared on the organization's site.
As Earth Glacier Frosts, Thermokarsts Born
Thermokarst lakes develop when permafrost, or terrain meant to remain frozen all year, begins melting. Since this occurs, large blocks of ice embedded into the ground melt, causing the terrain to collapse numerous feet.
Bacteria infiltrate the sinkholes left behind as water does.
"It's like opening your freezer door for the first time and giving all the stuff in your freezer to bacteria to decay," Walter Anthony described.
As per NASA's blog, there have been millions of lakes in the Arctic, but the majority are thousands of years old and don't release much gas nowadays.
Only the newest lakes, such as Big Trail, which opened just under 50 years ago, emit substantial levels of the gas, but this is not a trivial sum.
Big Trail Lake is one of Alaska's newest lakes and one of the largest methane emission hotspots in the Arctic.
Methane: The Main Greenhouse Gas
Despite carbon dioxide (CO2) remaining the leading long-term culprit of the climate crisis, methane leaks increasingly emerged as a critical concern for mitigating climate change shortly.
Methane is a greenhouse gas that traps heat rising from the ground in the atmosphere rather than allowing the Earth to cool.
This is 30 times more powerful at trapping heat than CO2. However, it evaporates more quickly than CO2, which persists in the atmosphere, as stated by the National Oceanic and Atmospheric Administration (NOAA).
"Reducing methane emissions is an important instrument we can employ right now to decrease the impacts of climate change in the short term and rapidly limit the rate of warming," NOAA Administrator Rick Spinrad previously suggested.
Human activities such as fuel extraction, agriculture, and waste all contribute significantly to methane emissions. Gas leaks from methane pipelines, for example, are progressively being sought since they can be observed from space and are rapidly mended.
According to NOAA, natural sources such as wetlands can also be significant methane sources. Studying how they can develop is critical since rising temperatures might trigger a "feedback loop" that "would largely be beyond humans' power to control," as per NOAA in April.
RELATED ARTICLE: New Lake in Alaska Formed Through Permafrost Thaw Belches Methane Posing Threat to the Atmosphere
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