THE EXPLOSIVE ARCTIC
A remote Alaskan lake bubbling up methane worries scientists that more northern lakes may be emitting dangerous greenhouse gas
Katey Walter Anthony has studied some 300 lakes across the tundras of the Arctic. But sitting on the mucky shore of her latest discovery, the Arctic expert said she’d never seen a lake like this one.
Set against the austere peaks of the Western Brooks Range, the lake, about 20 football fields in size, looked like it was boiling.
Its waters hissed, bubbled and popped as a powerful greenhouse gas escaped from the lake bed.
Some bubbles grew as big as grapefruits, visibly lifting the water’s surface several inches and carrying up bits of mud from below. This was methane. As the permafrost thaws across the fast-warming Arctic, it releases carbon dioxide, the top planet-warming greenhouse gas, from the soil into the air.
Sometimes, that thaw spurs the growth of lakes in the soft, sunken ground, and these deep-thawing bodies of water tend to unleash the harder-hitting methane gas. But not this much of it. This lake — Walter Anthony dubbed it Esieh Lake — looked different.
And the volume of gas wafting from it could deliver the climate system another blow if lakes like this turn out to be widespread.
The first time Walter Anthony saw Esieh Lake, she was afraid it might explode — and she is no stranger to the danger, or the theatrics, of methane.
In 2010, the University of Alaska at Fairbanks posted a video of the media-savvy ecologist standing on the frozen surface of an Arctic lake, then lighting a methane stream on fire to create a tower of flame as tall as she is. It got nearly half a million views on YouTube.
So now, in the Arctic’s August warmth, she had come back to this isolated spot with a small research team, along with her husband and two young sons, to see what secrets Esieh Lake might yield.
Was it simply a bizarre anomaly? Or was it a sign that the thawing Arctic had begun to release an ancient source of methane that could worsen climate change? One thing she was sure about: If the warming Arctic releases more planet-warming methane, that could lead to … more warming. “These lakes speed up permafrost thaw,” Walter Anthony said. “It’s an acceleration.” There was only so much the team would learn from the instruments they had hauled here. To get a firsthand look, they would have to get in. They’d brought their wet suits. Walter Anthony, who grew up close to Lake Tahoe, was captivated by Arctic lakes at 19, when she spent a summer at Siberia’s picturesque Lake Baikal. “I love the solitude of remote lakes and the mystery of what lies beneath the water surface.” Two decades and several academic degrees later, she was asked by a Native Alaskan group, the NANA Regional Corporation, to search for methane seeps in northwest Alaska, since the gas, despite its climate downsides, could provide a fuel source for remote communities. How do you find a lake in Alaska that leaks methane? Well, there’s one telltale sign: They don’t fully freeze over.
In April 2017, Walter Anthony put out word among residents of Kotzebue, Alaska, that she was looking for weird lakes. An email that month from a pilot led her to the Noatak region, not far above the Arctic Circle.
Last September, she made her first visit to the lake.
She brought her family and a graduate student to the spot, so remote it required several days of camping.
At first, the sheer volume of gases at Esieh Lake was slightly terrifying, but as Walter Anthony grew accustomed to the lake’s constant spluttering, her fear gave way to wonder.
Her sounding devices picked up huge holes in the bottom of the lake.
Most of Esieh is quite shallow, averaging only about a metre deep. But where the gas bubbles cluster, the floor drops suddenly, a plunge marked by the vanishing of all visible plant life.
Measurements showed that the lake dips to about 15 metres deep in one area and nearly 4.5 metres in another.
When they first studied them, Walter Anthony and her graduate student Janelle Sharp named these two seep clusters W1 and W2, short for “Wow 1” and “Wow 2.”
The next discovery came from the lab.
When the scientists examined sam- ples of the gases, they found the chemical signature of a “geologic” origin.
In other words, the methane venting from the lake seemed to be emerging not from the direct thawing of frozen Arctic soil, or permafrost, but rather from a reservoir of far older fossil fuels.
If that were happening all over the Arctic, Walter Anthony figured — if fossil fuels that had been buried for millennia were now being exposed to the atmosphere — the planet could be in even deeper peril.
For the second trip, Walter Anthony had brought a larger team of researchers, more equipment and her family — her husband, Peter Anthony, and sons, Jorgen, 6, and Anders, 3.
The team brought instruments for sampling gases, four inflatable boats, large crates of food, eight tents, a satellite phone for emergencies and two shotguns. The lake is frequented by grizzly bears.
A week before the trip, Walter Anthony had published a major study delivering worrisome news about Arctic lakes in general. Her husband — also a scientist at the University of Alaska at Fairbanks — was a co-author. The research tackled the central question now animating scientists who study permafrost soils, which can reach depths of nearly 1,500 metres and were laid down over tens of thousands of years or more as generations of plants died and sank beneath the surface.
Because of the cold, those carbonrich remains never fully decomposed, and the soil preserves them in an icy purgatory.
Now, though, as the Arctic warms, decomposition is starting up — and it gives off greenhouse gases.
The authors examined the prevalence of thermokarst lakes, which form when the wedges of ice within permafrost melt and create voids that then fill with water.
And they found that the continuing growth of these lakes — many of which have already formed in the tundra — could more than double the greenhouse gas emissions coming from the Arctic’s soils by 2100.
Overall, if Walter Anthony’s findings are correct, the total impact from thawing permafrost could be similar to adding a couple of large fossil-fuel-emitting economies — say, two more Germanys — to the planet.
And that does not take into account the possibility of more lakes like Esieh.
Another scientist, Frederic Thalasso, had travelled from Mexico City and spent days taking gas measurements around the lake. His initial results: Emissions from Esieh were very high — and clearly had something to do with fossil fuels.
His instruments also detected ethane, butane and propane — classic signatures of a fossil origin.
At this point, it would be premature to call Esieh Lake a sign of climate doom. It is a strange and dramatic site, but its message is partly veiled.
The coming years will probably reveal what’s behind Esieh and whether it has many cousins across the top of the world.