Permafrost

The Arctic permafrost is a personal friend of mine. I’ve spent weeks at a time hiking, camping, and rafting with permafrost beneath me. So two articles I just read about the Artic thaw had more than just scientific interest. 

The first article was about oil. We all know that the Arctic ice cap is shrinking as we speak. Some see this as an exciting event. It promises to be a boon to the oil industry, because it will open up whole new areas for deep-water drilling. It will also make shipping easier—like the trip between Europe or Russia and the US west coast or East Asia would be far shorter through the northern passages than by the old routes through the Suez or Panama Canal. On the other hand, environmentalists worry about the impact of oil drilling, shipping, and increased tourism on the fragile ecology of the arctic.

Along with the shrinking ice cap, there are also signs that the Arctic permafrost is thawing. This is a big deal. The second article discussed some new research suggesting that the thawing Arctic permafrost may be a key element  in rising temperatures in the Arctic—not just a victim but also a cause of global warming. The story goes like this: According to this research, about 55 million years ago, the Earth experienced a period of intense heating that lasted for tens of thousands of years. This heating was caused by atmospheric gasses. And the source of those gasses, it seems, was thawing permafrost in the Earth's polar regions. When the frozen soils thawed, the organic matter began to decay, releasing methane and carbon dioxide, which heat the atmosphere. And today, we may be seeing the beginnings of a similar cycle: increasing temperatures thaw the permafrost, which releases gasses that heat the atmosphere … and so goes the cycle.

Reading these articles took me back to my own encounters with permafrost. I first met the permafrost up close and personal on some long-ago backpacking trips to Alaska. Two images come to mind in particular. 

My first such trip started at a lake at the summit of the Brooks Range, an east–west range above the Arctic Circle that separates the bulk of inland Alaska from the northern plains and the north shore (of caribou breeding and oil drilling fame). A pontoon plane dropped us off near the shore of this lake and then disappeared into the clouds. There we were, three women heading into a trail-less wilderness—a guide and two experienced backpackers without a clue about what backpacking in Alaska would be like. Walking south on our first day, we passed what looked like a riverbank (except there was no river). Framed in this bank was an ice lens—which is just what it sounds like: a lens of permanent ice about 5 or 6 feet wide and about 3 feet high, buried in the bank. Our guide explained (briefly; she was a woman of few words) that there are ice lenses all over the arctic, mostly not exposed like this one was. I took a picture of her in front of it … unfortunately, it was before digital cameras, so I can’t share it, but I’ve included someone else’s picture of a different ice lens to give you an idea.

My next permafrost experience came in discussions with the woman who ran a bed and breakfast in Fairbanks that served as a temporary home before and after this trip (and also before and after two subsequent trips). Betty was a most interesting person, well suited to Alaska. She came because her husband had a job working construction on the Alaska pipeline. She stayed after they parted because she liked being where people pretty much left her alone and where she could see the Northern Lights with great frequency (she had some great videos!). Betty was taking architecture classes at the University of Alaska in Fairbanks. She wanted to specialize in building and rebuilding on permafrost. Her own house was built on permafrost. This was clear every time you walked across a room or set something on a table. Getting up at night was a perilous adventure, because the bedroom and bathroom were on totally different slants, each steep enough to throw you off balance if you were less than alert. The house above isn't Betty's (and that's not Betty!), but it makes the point. 

After talking with Betty about this, we began to notice lots of buildings around Fairbanks that were similarly askew. “Outside,” as true Alaskans call the lower 48, we would see these as run-down and poorly maintained. We’d probably use words like a “heap” or at best a “shack.” But the problem isn’t the owners’ care taking. It’s the permafrost. When the permafrost melts, the ground sinks. When the water freezes, the ground rises as the ice expands. But it does all of this unevenly because the ice isn’t evenly distributed in the ground and the heating from above is uneven.

It’s not just buildings that get all akilter. Roads become treacherous with “frost heaves,” bumps and dips caused by the shifting of freezing/melting water in the earth. I imagined subterranean ice lenses everywhere! All of this heaving happens at superficial levels, when the moisture near the surface freezes and thaws. Beneath this layer, though, is the true, solid permafrost—which is, literally, permanently frozen. Here’s a great diagram, if you’re interested in the visual-learner’s version.

Water sits on top of this frozen layer and, so it has nowhere to go when it freezes, except up. This also means that water flowing on top of this layer is very, very cold. Alaskan rivers, especially in the far north, can’t cut deep channels because the permafrost is too solid. So they spread out into several shallow channels; they’re called, almost poetically, “braided” rivers. I’ve included a picture so you can see what I mean. These rivers are ice cold because they flow along a bed of permanent ice. I say this from experience. That “trail-less wilderness” I mentioned includes wading across a lot of rivers. We even waded down the center of some streams because it was the only route through dense stands of willow. And they were cold!

So, when I read about this phenomenon that I’m calling the “northern melt” these days, I drift back to Alaska—Denali’s braided rivers and amazing wildlife, the wildflowers and eagles on the passes in the Brooks Range, the grizzlies wandering solo and the two muskoxen holding a stand-off on the tundra of the north shore. I think in micro terms about the costs of our indifference to the environment, in terms of the individual organisms and the individual scenes that I witnessed spending time on the permafrost.

And now it appears that we have growing evidence of the consequences of the northern melt in macro terms. It looks like the permafrost itself may play a huge role in the coming global warming. The irony of this is striking.

When they were building the Alaska pipeline, they built miles and miles of it above, instead of below, the ground because the hot oil would melt the permafrost. This would have been an ecological disaster, as everything from the tiniest arctic flower or moss to the largest grizzly or muskox has evolved in synchrony with permafrost.

And here’s another irony: the oil that comes to us through that elevated pipeline, carefully designed to avoid melting the permafrost, is part of the cycle that threatens that very permafrost. We drive our cars and heat our buildings with that oil, warming the environment, slowly melting the Arctic ice and the permafrost. And now, to come full circle, it turns out that the melting permafrost may actually contribute enough heat to drastically warm the environment by itself.

We’ve all heard/read about the long-term, human consequences of this process. Reduced to the level of the particular, the northern melt reminds me of ice lenses and Betty, frost heaves and frigid streams, Arctic flowers and tussocks, and the tundra creatures. I feel incredibly lucky to have seen them, even lived among them for weeks on end. I wonder how many more generations  will have that opportunity.