A Crack in the Edge of the World (2 page)

This is not an environmental book by any means. It is, more simply, the story of one remarkable and tragic event that befell California a century ago, when a 300-mile-long swath of the earth briefly shifted, wrecking the cities that lay atop it. But, though it is not intended to be a Gaia book, it seems right to tell the story of the events that so ruined the city of San Francisco in 1906 within the
context
of the Gaia idea. There is, for a start, an interesting synchronicity at work: At the moment when Thomas and Lovelock were putting forward their ideas (in the late 1960s, at the same time as the beginning of space travel and, in part, of course, because of it), the geological sciences were also changing very profoundly, as we shall see.

Neil Armstrong was able to gaze across the quarter million miles
that separate these two small planetary bodies and look directly toward that area of America from which he had come, at the hills and valleys of the selfsame rocks where he had grown up—rocks that established geology and the fossil record tell us belong to the Silurian Age. And I have no doubt that it was in large measure because of this most extraordinary vision—extraordinary both for Neil Armstrong and, in time, for the rest of us, too—that the birth was signaled of what is now coming to be regarded as an entirely new science. It was a science that was born and then helped to its feet quite simply by virtue of this new perspective that Neil Armstrong's view, even though it had been long anticipated by those who sent him and his colleagues into space, would shed on our planet.

What he saw—and what we saw through his eyes, which we now perhaps take somewhat for granted—was a thing of incredible and fragile beauty. It was a floating near-spherical body, tricked out in deep blue and pale green, with the white of polar ice and mountain summits, with great gray swirls and sheets of clouds and storms, and with the terminator line, that divides darkness and light seeming to sweep slowly across the planet's face as it turned into and out of the sun. It was a lovely aspect to contemplate. And it was a view that in time compelled humankind
to take stock
.

“To see oursels as others see us,” as Robert Burns had written. Here and now, all of sudden, we realized that we could do just that—and, with this unanticipated ability to do so, something about us suddenly changed. Almost overnight, and essentially because of this new world-view to which we had access, we discovered a whole raft of new reasons to ponder the oldest of age-old questions: just where we stood in the celestial scheme of things, what the universe and its creation might mean, and how the very earth itself may have first come into being. And such ruminations led, in short order, to the makings of the scientific revolution—and, most specifically, to the geological revolution—that is central to this story.

Like alchemy and the medicine of the leech and the bleeding rod, the Old Geology is a science born long ago (most formally in the eighteenth century): one that, unlike so many of its sister sciences—chemistry, physics, medicine, and astronomy—never truly left the era of its making. Since its beginnings geology has been a field mired in some alluvial quagmire, defined by dusty cases of fossils, barely comprehensible diagrams of crystals, and the different kinds of breaks that were made in the earth's surface (as well as by unlovely Continental words like
graben, gabbro
, and
graywacke
), and explained with cracked-varnish wall roller charts showing how the world may have looked at the time of the Permian Period. To me it remains the most lyrical and romantic of the sciences; but in terms of glamor, and when compared with astrophysics or molecular biology, the Old Geology is somewhat wanting.

The New Geology is, on the other hand, a creature fashioned wholly from the science of the space age, from the attitude that was born when Neil Armstrong first looked back and gazed at the earth. It is a science that now presents us with an entire canon of new ways in which we might look at this planet and at our stellar and solar neighbors.

It seems to me quite fair and proper that the principles of this new science should underpin everything that follows: the terrifying and extraordinary event that enfolded the small but fast-growing western American city of San Francisco one twilit California morning in the middle of April 1906.

Many other scientific disciplines that are revolutionary and dauntingly modern—cosmology, genetic engineering, quantum mechanics—have been formed or founded in recent years, and had no past to hold them back. But geology is different. It is a very old science indeed and hugely proud of its origins: Portraits of the bearded ancients of its founding priesthood invariably hang in esteemed positions in departments from Anchorage to Adelaide. Its antiquity, however, has long been a problem for it, one that has tended to inhibit too many of its
practitioners from escaping the glutinous hold of its earliest ideas. Students who remember measuring the umbos of brachiopods or trying to fathom the mysteries of recumbent folding can reach through the centuries and join hands with students who were taught the same topics at the time of George IV and President John Adams. It was only when the professors happened to mention in more modern classes such wonders as the K-T boundary event, with the massive dinosaur extinctions that were mysteriously triggered at the end of the Cretaceous Period (perhaps by a monstrous collision with an immense asteroid), that geology as taught seemed, briefly, to come alive.

Now, however, thanks to a number of recent developments—space travel being one of them, the most spectacular but in terms of science not the most important—geology has suddenly and seriously changed, and at a pace so rapid as to bewilder and astonish all who come up against it anew, or return to it after a while away. It is probably fair to say that never before has any long-existing science been remodeled and reworked so profoundly, so suddenly, and in so short a time. Wholly unimagined visions and possibilities allow us to contemplate our planet in brand-new ways. These means have evolved right before our eyes, and, to the less prescient among us, they have done so well-nigh invisibly and, moreover, in rather less than half a century.

Thanks to the attitudes and instruments and scientific philosophies of the new science, all the events of great geological moment—with chief among them the earthquakes and volcanoes that so plague humankind—can now be seen and interpreted in an entirely fresh context, and in a manner that had rarely before occurred to those who practiced the confusing and cobweb-bound older science with which (from memories of school and university) we are still so vaguely familiar.

IT WAS NOT NEIL ARMSTRONG'S
venture alone that brought about this transformation. It is fair to say that geology flowered as rapidly as it did because at almost the exact same moment as the rockets started to soar up through the stratosphere from their bases in Florida
(and from the cosmodromes in Baikonur—for this new perspective was one offered to Russian scientists too, of course) something else occurred. A previously little-known professor in Toronto (a man whose very ordinary surname—Wilson—might have kept him marooned in the shadows forever, had not one of his given names—Tuzo—been so strange) drew up the foundations of an entirely new geological subdiscipline, the now all-too-familiar theory known as plate tectonics.

Plate tectonics and space travel each burst onto the world stage at the same time—plate tectonics becoming fully developed by 1967, manned lunar exploring getting under way in 1969—and it is this that led to the unprecedented evolution of the science that was common to both. I shall try to explain the more relevant details of plate tectonics later in the story; but in essence it was a theory that also happened to encourage its believers to stand back, as it were, just as Neil Armstrong was doing at that moment. Plate tectonics allowed us—compelled us, even—to view the world as a complete entity, for the first time to look and to see
the earth entire
.

For it should be remembered that every single one of those Old Geologists—the tweedy figures who, with hammer and lens and acid bottle, had explored and observed and thought and written since the days when it was first realized that the earth is actually very old and that rocks are laid down with some natural purpose and that no deity had anything much to do with the actual manufacture of the planet—found their evidence for the theories and principles of the Old Geology in the rocks, fossils, faults and minerals that were scattered around simply and solely
on the surface of the earth
. They made crucially important discoveries, true; they laid the foundations for this most elemental of disciplines, true; but they did so by examining only the topmost layers—or at most the topmost few miles of thickness, if you will—of the planet.

And that, it is now realized, was a very limiting way indeed of conducting the science—a science that, after all, should more properly be concerned with the nature and history of the earth
in its entirety
, and not with its surface alone. Before the 1970s we had knowledge about the earth's outer cover and not much more. What we wanted to know
involved, if we thought about it, much, much more. We wanted to know—and geology was, in its theoretical essence, established purely so as to enable us the better
to
know—about the earth as a whole. And when the intellectual revolution of the sixties came about, we started swiftly to understand that up until that point we had, quite literally, only been scratching the surface; we had never considered the earth as it truly deserved to be considered.

It promptly started to dawn on those sixties geologists who had listened to Tuzo Wilson or his acolytes, or who had seen the spacecraft pictures, that it was somewhat misleading for a science to draw conclusions about the earth entire by examining only those minor features that occurred upon, or just beneath, the planet's outer covering. A fault in Scotland or the relic of a volcano in Montana or the succession of types of trilobite that had been found buried in a shale high on a hillside in British Columbia—such things might be interesting in and of themselves, but only when they were viewed in the context of the big picture, of the planet as a whole, were they able to offer up evidence that allowed the whole-earth portrait to be inked in and made to look something like complete.

So this, then, lies at the heart of the New Geology. The world is these days viewed by most as one entire and immense system, the most refined of its details all interwoven with the biggest of big concepts. It is a living system four and a half billion years old. In a purely physical sense it is an entity warmed up from inside by radioactive decay, with fragments of its fairly recently cooled crust moving about on top of its more mobile inner self, and with solid rocks that have formed (or are still forming) on or beside these fragments creating continents or the floors of oceans. These rafts of solid rock have since been (or are still being) folded or lifted or broken apart as the plates on which they ride move about until they collide and bounce and dive beneath one another. In places, the rocks rise up to great heights; these are eventually eroded, causing the formation of sediment. Ageological cycle of creation and decay continues, endlessly. And meanwhile there is life, almost in global terms a brief irrelevance; animals and plants evolve and disappear by turns on the various wet or dry surfaces of the
planet according to a series of complex sets of rules that have been laid down by the practical realities of tectonics, of temperature, of pressure, and of almost limitless quantities of time.

The finer details of these things have been studied for decades—such arcane niceties as the suture lines of ammonites (by which one can determine the species and subspecies of this particular beast, which floated gently about in the Mesozoic seas), or the varying degrees of sphericity of the ooliths in a Jurassic limestone, or the patterns of those parts of bivalved creatures that are inelegantly known as muscle scars. But now, in the light of the whole-earth, big-picture view of the science of which they are so infinitesimal a part, they seem tangential to the broad realities of the New Geology, as the pores in an elephant's skin do to a biologist or the volume of sap that courses through the leaves of a live oak from San Antonio does to a forest botanist.

Which is not to say that such things are unworthy of our fascination. Small pieces of puzzles can often lead to grand ideas: The beaks of the Galápagos finches, after all, led Charles Darwin to his big notions about natural selection, the origin of species, and evolution. But it is important to remember that Darwin had at the time all of what was known of earth's biology at his intellectual disposal—every beak and claw, every feather and fin was there, and his journeys took him to far and remote parts of our planet, so that he saw and thought about evidence from all manner of perspectives. When he sat down to write and think at his desk in Down House, he had an immense and almost unimaginable accumulation of information available to him, the finches' beaks being just a scattering of tiles from the great mosaic of biological knowledge.

But, by contrast, geology, at least before the 1960s, was able to lay out before its practitioners only the tiniest portion of available information—very little more than the superficial, the minute, the peripherally relevant. And then, in the nick of time (for without it, where would geology have gone?), everything altered: Along came the astronauts and the unmanned satellites and the space-born magnetometers and gravimeters and mass spectrometers and ion probes, and along
came J. Tuzo Wilson and a whole army of like-minded tectonicists. They, combined with the new way of looking at the earth, taught the Old Geological community that there was much, much more to know—and what was once merely a hunch, an inner feeling, became a settled idea. It became abundantly clear that very few grand theories could actually ever be derived from minutiae such as ammonite suture lines and oolith sphericities and relative umbo sizes alone, except forensically; and that nowadays the grand geological ideas are the ones that truly matter.