Sculptures of Struggle

by Andrew Colvin ‘04

In the late afternoon of an August backpacking trip, we decided to rest from treading the big mountains to take a small side-trip to an unknown “X” on the map called Moriah Gorge.  Our boots chewed the earth as we climbed over hills and balanced ourselves across slopes, watching the land rise on our right and plunge steeply on our left.  After a few miles, we came to a stream that looked like any other of the countless waters that flowed through my mountain memory— just more water moving over rock, roaring its way through the narrow canyon as it fell to its final destination, its clearness painted by the glint of the afternoon sun and the reflection of my peering face.  If I hadn’t walked around the corner, it might never have cut its mark on me.

When I investigated the shadowed gorge hiding past the river’s bend, the river revealed to me a creation unlike anything I had seen before, or have seen since.  In a tall wall of rock that divided the river in two, the river had cut a half bowl from each side.  It was almost as if some mountain giant had taken an ice cream scoop to the solid piece of granite, making two perfect quarter spheres with a radius five-foot radius. As I peered at them, awe and puzzlement dashed across my face.  I could understand the smoothness of the rocks underneath the stream.  We all know that over time the driving waters of a river wear down its stones until they are the polished eggs so comforting to run your fingertips over.  But this sculpture was far more mysterious than a polished egg, because although it was created by the erosive power of the water, its beauty revealed that it could not be forged by mere power.  There was a wisdom of form, a notice to detail, a precise polish in this piece of art that even the most careful of human hands might fail to replicate.

It was almost as if some mountain giant had taken an ice cream scoop to the solid piece of granite, making two perfect quarter spheres with a radius five-foot radius.

Suddenly, the senseless sound of crashing water against rock became the patient, careful hum of creation.  As I looked around to the other sculptures of granite as carefully shaped as this one, I realized that even more important to their creation than the river’s brute power was the temperance and control of that power.  The artistic hands of the river are relentless, but also reluctant.  For if it had its way, the river would choose a path of no resistance, hoarding and building its power with an uncontained momentum, driving straight and smooth. But standing in the river’s way is the rock that divides the waters, slows them down, contains them, and resists them, fighting the river’s power by making it work for its passage, in the end proudly wearing these sculptures as the scars acquired in their battle. Without this struggle between water and rock the river would simply be water without impression.

Nothing portrays this struggle better than the turbulence of a river, which I could see in the rapids of the gorge where the smooth, clear flow turned into foaming, white chaos. Turbulence is caused by all the obstructions that stand in the river’s path— boulders in the middle of the stream, the canyon walls that contain it, even the smallest bumps in the rock.  All these obstructions, small and large, split up the main body of the river into millions of different currents, going around or over rocks, driven into dark corners and hidden holes. These diversions transform one brute force into a million artistic ones. Instead of merely flowing smoothly and superficially over the rock, the river’s struggle with these obstructions reaches into the rock.

The turbulence I saw frenzying the surface was only a small indicator of the turmoil that goes on underneath, as currents run and mix, veer and overturn. This underwater dance of the currents creates focused and intricate forces at the points where the flow is diverted into different directions.  At these points of separation, two flows can make a vortex: a spiral current of water twisting like a tornado.  For instance, as a river flows around a boulder, one current travels in a straight path alongside the stone while another current follows the shape of the rock, traveling around in an arc. Where these currents separate, the straight flow pushes on the other as it goes past and accelerates it.  This forceful acceleration to a high velocity creates the spinning current of the vortex.  Like twirling your partner on the dance floor, the vortex picks up anything from fine sediment to large rocks, spinning them around and around, wearing away the rock as quickly as the night flies with someone whirling in your arms.

During the few minutes I watched, the vortex current scooped the bowls deeper as it banged rocks and pebbles against the wall in a perfect circular motion.

All around me, I saw the evidence of a hundred such dances. Grooves formed under ridges in the rock called flutes, and wide, deep holes in the river bottom aptly named potholes. Even the huge half-bowls that first sparked my amazement were formed from huge vortex currents generated as the granite wall split the river in two, making currents simultaneously flow past and hug the rock. Over the course of a few thousand years, and during the few minutes I watched, the vortex current scooped the bowls deeper as it banged rocks and pebbles against the wall in a perfect circular motion. This structure was here because of the obstacles that forced the river to stop its austere march to the sea, dividing it into different waters that break out into dances all their own.

In the struggle of water and rock there is not only diversion, but also containment, as the rock seeks control over the river, to make the water go where it decides.  The river must unwillingly follow, yet every once in a while it wrathfully shows its resentment in rare process called cavitation.  As water is guided through a tight channel in the rock, like a crack or a joint, the water pressure decreases as its velocity increases.  Bernoulli determined this relation in finding that the energy of the river is constant, dependent on the water’s velocity and pressure. To keep the energy constant within this closed system, as one goes up, the other must go down.  So when the pressure falls in the contained place, the water expands, forming tiny bubbles in the water. Coming out of the contained place, the water slows down and the pressure suddenly increases, compressing the air and making the bubbles implode.  The water around it rushes inward to fill the space with a concussive force that hits the nearby rock like a hammer. Small cavities are formed in the rock, hence the name cavitation.  Angry at being controlled, struggling against its bonds, the river rages against the rock, opening cavities that will later become opportune places for carving vortexes.  Thus, from battle comes beauty once again.

The beauty of these sculptures, though, relies not only on the rock the river breaks away with its spinning currents or imploding molecules, but also on the rock left behind.  The sculptures of the river are monuments to the resistance of rock, for without that, there would be nothing left to see.  Of course, not all rocks can hold their silent defense forever, for all types of rock have different levels of resistance depending on the hardness of their molecular structure.  When these different levels of resistance are placed next to or on top of each other, the most dramatic of contrasts occur in the sculptures that are left behind.  Cascading down with the waterfall, my eyes saw this contrast in a knickpoint— a place in a waterfall where a resistant layer of rock is placed on top of a less resistant layer.  The river was unable to erode the top layer, but easily chewed the layer beneath, creating an overhanging shelf from the hard layer for the water to cascade into empty space that was once rock.  Over time the shelf falls with nothing to hold it, and a new knickpoints starts again a few feet behind the old, as the waterfall retreats upstream.  The lost rock layers of knickpoints are reminders that if the artistic hands of the river had its choice, its chisel would carve stone into thin air and fine sediment.   Luckily for us, the resistant layers of rocks are reminders that some rock is as relentless as the chisel.

As the bright afternoon became a dim evening, I put my feet into the cold water for the last time, watching the water run through and around my legs, creating some turbulence of my own.  But the moment could not last and we trekked back to camp with the slope now climbing on our left, and diving downward on the right.  And even though I haven’t been back to Moriah Gorge since, I still think of it every time I see a stream.  Even rainstorm streams in the streets.  And every time, I take a second to look closely at the rock, to listen closely to the water, to feel the struggle between them.  No matter which stream I watch, the river tries to flow without resistance, but the rocks are there to divert them, to contain them, to resist their advance.  With all the work it takes a river simply to flow downhill, its trip over the rock certainly isn’t free.  Maybe creating these sculptures is the fee the river reluctantly pays for its passage over the highway of rock, and Moriah Gorge was one such place where the river dug deep into its pocket.  From now on, I’ll look for every tollbooth I can find.