'The reality is, I think we're going to get more ponds.'

Exposed permafrost melting rapidly on Ellesmere Island


The High Arctic lowlands of Eureka Sound on Ellesmere Island are melting.

Nowhere is this change more dramatic than in walls of exposed permafrost, extending for hundreds of metres, that are retreating as fast as one metre per week.

"It's an expansive wall of ice, but it's retreating backwards. They're expanding continuously in all directions," said Dr. Wayne Pollard, a professor at McGill University who is studying the land forms.

The ice walls are odd, because it's five to six degrees warmer inside them than outside. Pollard explains this is because the "icy, muddy surfaces" of the permafrost focuses the sun's rays, much like a magnifying glass would, and generates heat, which speeds up the melting.

Pollard calls the land forms "retrogressive thaw slumps," and they look like natural amphitheatres carved into the land. One day, Pollard says they will become lakes.

Much attention has been given recently to a study that shows some High Arctic lakes are disappearing. But Pollard says, given the amount of permafrost that will melt as the climate warms, he expects the High Arctic of the future to be wet and lush, rather than dried up.

"The reality is, I think we're going to get more ponds. These Arctic ponds may dry up, but there's going to be a lot more," he said.

Pollard says the High Arctic will likely look much like South Baffin, or the Mackenzie Valley, in several decades, if the climate continues to warm.

Melt water will deepen streams, carve out gullies, and feed an emerging blanket of tundra over areas where few plants currently grow.

"You can imagine the increase in vegetation. Willows will get bigger. They'll be tens of centimetres tall, rather than centimetres."

"You'll see foxes, and a lemming. And the whole food chain will follow."

This summer Pollard and a graduate student, Jackie Grom, are closely studying one thaw slump 10 kilometers south of the Eureka weather station.

But he says there are as many as 170 similar sites in the Eureka Sound area.

Pollard suspects the formations began when nearby streams washed through the area and washed away fine sediment, left behind from when a shallow ocean once covered Ellesmere Island's lowlands.

That erosion exposed permafrost that started to melt, and started the same chain reaction that is causing the slumps to retreat further today.

In the Yukon, Pollard has observed similar slumps retreat as fast as 30 metres in a week.

Sites in the western Arctic reveal that such melts have occurred in the past, Pollard said, and serve to remind us that although today's changes in the Arctic may seem extreme, "we're still not as warm as it was 5,000 years ago."

At those western sites, some of the exposed ice looks like the buttress of a cathedral. No wonder Pollard, who has worked in the North for 30 years, says each summer he returns to the field, he feels like he's in church.

"For me, it's a spiritual experience."

"It's not a logical thing. You're wet, you're cold, you're frozen. It's just what I want to do."

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