Boundaries
by Jack Nisbet

Jack Nisbet is the author of The Mapmaker's Eye, Sources of the River, Purple Flat Top, Singing Grass, Burning Sage and Visible Bones. His newest, The Collector, won a 2010 PNBA Award.

March 2012

 

Fire and Ice

 

 

 

Ice waterfall on Bonnie Lake south of Spokane
by Charles Gurche

 

A space of five miles square, recently in a state of igneous fusion, in the process of cooling has been broken up into immense ledges and rolled masses, like the breaking up of a great river of ice.
David Douglas, from Kilauea crater on the big island of Hawaii, 1834

 

When Scottish naturalist David Douglas visited Hawaii almost two centuries ago, he was under the influence of Charles Lyell’s recently-published Elements of Geology—a classic geology text which set forth the notion that all the basic principles of earth-building remain at work, and that anyone who carefully studies their surrounding landscape can watch them happen. For Douglas, who had made several trips into the wild coulees and scablands of the Columbia River Basin, studying the flow and cooling of hot lava in Hawaii provided real-time lessons into how the formations he marveled at in the Inland Northwest had come into existence. And because Douglas lived in the Little Ice Age, when the Columbia River regularly froze solid during the winter—in the winter of 1830 he reported that the river at Fort Vancouver, opposite modern Portland, remained closed for over a month—he naturally could compare the cooling and fracturing of hot magma with the grinding processes of spring breakup.

 

That approach of comparing fire and ice to learn about geological formations still works fine today, even without rupturing volcanic vents and dependable full river lock-ups. Every winter offers endless variations on basic patterns of temperature fluctuation, of freezing and thawing, of the formation of ice and the deposition of snow. With each new cold season, every different body of water recasts the wrenching transition of liquid to solid; every warm season reverses the process for all to see.

 

The relatively cold, dry beginning to the winter of 2011-12 provided a platform to get out and experience this transformation anew. With photographer Charles Gurche, I tried to cover the story in double time, on ice skates, in order to feel the changes through moving feet.

 

The first real stretch of cold weather came in early December, and brought smooth ice to several open marshlands south of Spokane. As always, variables that include artesian springs, organically rich black mud, stands of vegetation left over from a dry fall, and the churning legs of lingering geese assured that each body of water produced a different texture of ice.

Bubbles in Black Ice, by Charles Gurche

As we tried each one out on skates, we could trace the mysterious formation of bubbles, all sorts and sizes captured in frozen glass the moment the water solidified. In basalt scablands scoured by Ice Age floods, it was tempting to compare this endless variety of bubbles to certain volcanic rocks that surround the wetlands—in tribal sweat lodges they were once known as “whistlers,” because they come riddled with burst gas bubbles that make the steam come alive.

 

When single-digit temperatures hung on in mid-December, farm ponds and then flood-scoured lakes turned over, allowing us to follow black ice for miles. As the ice thickened to five inches and more, the push and pull of the larger bodies of water sent deep cracks from shore to shore, tearing the surface apart. Watching such powerful forces at work offered direct lessons in plate tectonics. Sheets would bump and grind against one another, separate, then bond again. Tops would shatter in to fractal patterns that could catch a skate and send us flying. Pressure ridges buckled clashing ice sheets upward and dropped them down, forming distinct steps that we had to hop across to avoid getting tripped. When one large sheet rode up over the top of another, we were watching the process of continental subduction on a small scale. When space opened up between two sheets, we could imagine bowhead whales feeling for open leads as they rounded Point Barrow in Alaska.

 

In the 21st century, winter’s cold breath is never a constant force, and after Christmas warm snaps and Chinook winds began to eat away at these natural rinks. Surface bubbles were scoured out to create pits of tinkling glass. Areas where vegetation poked through held the heat of the sun, melting curved pock marks into the surface. In some areas, strong steady breezes rolled up ripples exactly like sand on a tidal beach; in others they carved bubble clusters into large oval depressions that looked like mirror images of the patterned ground hummocks that dotted the surrounding scablands. Now the trick to skating was to weave back and forth among the imperfections, feeling for smooth ice.

Ice Cracks, by Charles Gurche

 

On some wetlands the alteration of warm and cold weather actually warped the entire surface, so that we were skating up- and down-hill as well. Terrain skating, we called it. It showed us the way that intense heat and pressure over time can bend entire layers of stone, which is exactly what happened to the warped bedding of ancient rock formations in the North Columbia country.
When early January snows came down on this mess and refroze, they formed white ice. While not exactly smooth, this was sometimes skateable enough that we could work our way down the length of a lake, as long as we avoided the larger bumps, ruts, and ripples. It could be slow, messy work, much like the churning together of melting snow, thawing ground, and rotting vegetation that mix up new soil every year.

 

One last cold snap put all these forces into play at once. On a shoestring lake well protected from the sun, waterfalls leaking from the cracks between basalt flows froze solid, and long stretches of black ice returned. Even with the knowledge that we will never see the same extremes of steady cold that David Douglas experienced, such conditions still allow a glimpse of deep time.

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