Erratics

Craig Holt Segall

Erratics

aren’t.

There is a logic to glaciers:

The world depends on nothing – wobbles—
cold shadows gather on the tundra.
Or the spine of some broken new range weathers,
makes weather, glazes cirques in blue ice.

Changes accrete, like snow.

There is a mechanic behind things—
A winding, an unwinding.

You could stand in this small wood – it is early spring,
and the old boulders rising from the ferns are mossy,
small white flowers blooming around them –
you could stand here, and look back along the arcs of time,

to see each stone taken up, held fast in the ice,
carried north, set gently back in some far ridge,
and then the ridge itself lowered, unsplintering,
back into the melt,

and you could look up, then, on a world elsewhere in its course,
through the branches of vanished trees, through a humid sky,
at a younger star.

The Science

Although glacial erratics - boulders deposited from passing ice sheets - may seem random, and are so named for that reason, they hold clues to a deeper logic. Walk through a wood, or across a moor, and you may notice large boulders, some balanced precariously, sitting out-of-place from the surrounding rock. These boulders were plucked from far hills by long-melted ice sheets, and deposited after the ice receded, leaving a signature of another kind. Ultimately, ice ages’ extent and duration are determined by the Earth's orbit, and atmospheric composition (which is heavily influenced in the long term by the amount of rock exposed to the atmosphere). Thus, the movement of the world helps determine even the placement of rocks in a wood. Were we able to find the clock back, we'd find ourselves first under the ice, then in a pre-glacial world, a younger world under a younger sun, long before the ice swept through. Even a landmark as unremarkable as a boulder in an unusual spot speaks to the changing climate of the world, and hence of the way the Earth swings through space. Though we humans are surface-bound, and time-bound, we can access deep time simply by recognising the forces that formed our daily walks.

The Poet

Craig Holt Segall is an environmental advocate and poet. His work, of various sorts, has been published in the Stanford Law Review, Canary, the Tule Review, Riverteeth, the Environmental Law Reporter, and Ecology Law Quarterly.

Next poem: From the Flaming Skull Nebula by Susan Taylor