TO circumnavigate an island in the North Atlantic is to achieve a unique perspective on some of the most striking scenery in North America—the plunging hillsides, the cliffs darkened by a sea that seems to pound them violently even when the winds are lazy—the sudden sense of solidarity and shared curiosity with adventurers who passed this way centuries ago. And yet, in the larger sweep of time, it was not so long ago at all, but a blink in the lifespan of a world that has been shaping this topography for more than two million years.
As the earth’s temperature fell during what we now know as the last ice age (ten to eighty thousand years ago), water froze into glaciers that covered the top of the planet, including all of what is now called Canada. Oceans, created by a great continental rift that began more than one hundred million years before the glaciers, dropped fifty fathoms, exposing what we now see, looming and unapproachable, before our eyes. It occurs to the anxious modern mind that the process that required tens of thousands of years to freeze the top of the planet is now working in reverse, accelerated to the point where a thaw is discernible in the span of a single human lifetime.
We are now warned that the seas are rising again. But twenty-five thousand years ago, the seas withdrew. Humans learned to fashion tools and weapons from metal instead of stone, to refine minerals for making heat and energy, food and light—a marriage of human creativity and the bounty of the elements. Timeless geophysical events would set the stage for apocalyptic destruction, but also shape the opportunities for our deliverance. The nutritious soil sprang green with vegetation. People evolved, thrived and spread, adapted, reproduced and struggled to repurpose rock and soil and trees and other species for food and shelter. In time, humanity was intimate with the surface of the planet, or most of it. At home on top of nearly all the oceans.
But what lay deep beneath the surfaces of land and sea would, until modern times, remain mysterious, and even now, except where wealth was an incentive, a matter of indifference to all but those with arcane interests—the scientists and the dreamers.
And yet, it is easy to imagine the land we see, travel, live upon, stripped of its familiar vegetation and reproduced beneath the oceans. The highlands and lowlands, the cliffs and valleys, the mountains and fjords and canyons and vast plains that account for more than 70 percent of the earth’s surface—a world that remains mostly inaccessible to mortals. But we are able to know it and see it in our mind’s eye because it is merely a bald continuation of what we see around us.
FOR North Americans, the nearest and most familiar and accessible part of that hidden world is the Atlantic continental shelf, a submerged landmass that projects outwards from the shoreline, relatively shallow, until it begins to slope down through the continental rise, yielding to the vast Sohm Abyssal Plain, a hilly expanse, in places several miles below the surface of the ocean.
As the slope descends, it is split and criss-crossed by steep trenches and canyons, which both deliver and collect sediment from the land and from the ocean bottom, where the sea is shallower. One such trench, the Laurentian Channel, extends from the confluence of the St. Lawrence and Saguenay Rivers, delivering sediment from erosion and glaciation to the underwater edge of where the continent once ended.
During the height of the ice age, the east coast of what is now called North America extended more than a hundred miles farther than at present. A larger, wilder Hudson River carved an immense channel, not unlike the Colorado River did the Grand Canyon, across the continental slope before the waters rose again.
The submerged valleys and the canyons there became collection systems for detritus—silt, stone, sand—accumulated over a span of time that can only be approximated. Time that is inconceivable to ordinary mortals except as abstract ages, epochs, eras. Time measured in the millions of years, never mind millennia.
And then, in the vastness of nature, as in human experience, there comes a moment, calculated in mere seconds, when everything will change and we are dwarfed and mortified by our incompetence and impotence. And such a moment came at 5:02, Newfoundland Standard Time, on the afternoon of November 18, 1929.
DEEP below the north wall of the Laurentian Channel, a vast slab of the planet’s brittle shell, along what scientists call a strike-slip fault, jerked violently.1 The earth’s crust, a series of solid plates, floats on a thick fluid mantle almost two thousand miles deep. It’s mostly stable because the plates are usually stuck together, but now and then, they slip, let go, creating the sudden jolt of energy we call an earthquake.2 Most of the time, the result is noticeable only to people who read seismographs. But the slippage off the coast of Newfoundland in November 1929 created an unmistakable surge of energy, unleashing a disaster that would unfold in real time and unexpected ways for decades.
There were actually three slips in a period of twenty-seven seconds: a major lurch on a fault line running to the northeast, followed by two lesser jerks along nearby fractures. And then a momentary stillness while the pent-up seismic energy shot out in waves that caused a violent shifting of the silt and sludge clinging to the sides of those sub-sea ravines and canyons. And suddenly, a submarine landslide was tumbling down the southern edge of the continental shelf, gathering speed and sludge and water, racing down the continental rise and, flushed finally from the canyons and the valleys, fanning outwards onto the vastness of the underwater plain for hundreds of miles.3
The full scientific account of what happened that day presents a spectacle we can only imagine—and even then, of dimensions that stagger the mind of the non-scientist. The impact of the disruption deep in the earth’s crust shook up an area of the continental slope about the size of Israel; it sent the equivalent of a mountain range of mud and sludge tumbling to the ocean floor.4 The avalanche, moving at more than sixty miles an hour, soaked up water as it slipped downwards, gradually turning into a heavy, soupy underwater wave that would continue moving for more than thirteen hours, redistributing what had been shaken loose over the unseen world below the ocean.
But it was what was happening along the way that would capture the attention of scientists and engineers for decades. All telegraph communication between North America and Europe in 1929 passed through cables that criss-crossed the continental shelf and slope and the adjacent deep-sea basin.5 The earthquake’s epicentre was in the middle of this dense network. Six cables lying at depths of between 150 and 1,800 fathoms were snapped immediately. The breaks continued in a sequence that could be precisely timed by onshore communications stations until the relentless current severed the last one thirteen hours and seventeen minutes after the initial shock. There were, in total, twenty-eight breaks in the twelve affected cables on the slope and in the ocean basin. It would take almost a year to repair the underwater damage.
On the nearby land, unsuspecting families were about to experience an onslaught that would mark them for a lifetime.