Scientists are as vain as other people, they just tend to hide their vanity inside empirical corroborations and pompous notions of authority. Geologists are among the proudest researchers and theorists in all of science. They can point with confidence and pride to the advances made in their field, beginning with the discoveries and confirmations which begin in the 19th Century, and continue all the way down to our own moment, the era of plate tectonics. We all like plate tectonics, because it explains much of the seismic and volcanic activity which mankind has been experiencing since . . . well, the Beginning.
For those of you who don't know it, the earth is a very hot ball of matter. The interior of our planet is very hot. The crust, the part inhabited by living organic matter, is extremely thin. And it's comparatively fluid. That may seem counter-intuitive. Rocks, after all, we think of as brittle, hard. But the truth is the surface of the earth is more like jelly than granite. And it rests not on "bedrock" but on a bed of very hot stuff which is inherently unstable. Planets are made of star-matter, they're fragments of something very much larger which exploded. These were very hot, very energetic events. The fragments of the Big Bang are still smoldering. That fire, that energy, is comparatively long-lived, in human time. In fact, when we're considering what is referred to as "geologic time" we're generally speaking in terms of tens of thousands, or hundreds of thousands, or millions, or tens of millions, or hundreds of millions of years. Segments of time of that extent tend to dwarf human time: for instance, the life of a single individual, or the length of a century, or of a millennium. In human terms 1000 years seems like a very long time, many generations. Most people lose track of their ancestors within a generation or two--those cultural memories gets lost in the distractions of the immediate present.
Geologists now know that geological events cause enormous changes on the earth's surface, and sudden, violent events (like large volcanic eruptions, or larger earthquakes) quickly get people's attention. But the intensity and effect of such events tends to be exaggerated in the public imagination. As man has acquired more control over his environment, we've become habituated to the notion that we can mitigate against such occurrences. We can use our fear and apprehension to motivate ourselves to make more concerted efforts to control our environment, or, failing that, to prepare for the predictable consequences of regularly occurring geologic events. It seems sensible to make reasonable mitigations that could save society from needless harm and destruction. But having said that, there are other considerations that complicate and undercut the optimistic slant that scientists put on the value of our knowledge of geology.
For one thing, geological events are so large, so powerful, that it's unreasonable to assume that mankind will ever command the energy and leverage required to have any significant effect upon, or control over, their progress. You can't "stop" a volcano, any more than you can influence the orbit of the moon. You can't hold back an earthquake fault. These are phenomena completely beyond our control. Man stands in awe of such natural forces. They are like gods. They rule our existence, albeit fitfully and unpredictably.
Geologists of course, would like to believe that science can eventually explain everything. That's what drives scientific inquiry. We've gone to the moon. We've figured out natural selection and the DNA code. We can measure the speed of light. We know about Black Holes. We've figured out relativity, partly. We should be able to study plate tectonics, to map the earth's crust, and to deduce from our measurements the frequency and likely times of geological events like eruptions and fault slips. And there's been considerable progress in our increasing knowledge of why earthquakes happen, and what their frequency seems to be, just by collating empirical observations made over time.
It's become fashionable over the last quarter century, for the media to encourage people to "get serious" about our awareness of the impacts of large geologic events. Every few months, they'll have a fear-mongering exposé, filled with dire warnings about the terrific dangers to society of earthquakes. Geology has provided us with reliable maps of all of the earth's fault lines, the margins of the plates which make up the shifting pieces of the earth's crust. We know where the faults lie, and we've begun to make time-lines of the rates of occurrence of slippage along the ones that are the most active. But here is where the contrast between geologic event times, and human event horizons, run parallel.
In human time, whole civilizations can be born, expand into great cultures, thrive and decay, within a couple or three hundred years. Cities can be built, the land brought under cultivation, and the population explode by millions upon millions. This happened in North America after the first European colonizations along the Eastern seaboard. Thirty generations of human time. Buildings and roads and reservoirs. Harbors and canals and power grids.
Volcanic eruptions and big earthquakes are frightening things. Not only because they happen unexpectedly, but because of their evident force. They upset people, and they can be destructive. Earthquakes can cause buildings to collapse, roadways to buckle, and can cause fires, and interruptions in vital services such as water, power, sewage. In developed areas, the amount of damage they cause can be staggering, especially where construction practices, and service systems are rudimentary and fragile. And humankind has shown little regard for the advisability of building in areas known to be at risk for such events.
But the larger question still arises: In what ways do geologic events challenge our ability to work around probable occurrences? Are there practical steps that can and should be taken to minimize or mitigate the dangers and damages associated with them? If, for instance, it is reckoned that a certain earthquake fault is known to slip or slide once every 100-250 years, does it behoove society to go to any lengths to prepare for the "next big one"? The popular view these days, is that we should be getting about preparing for earthquakes.
The comparative study of different kinds of risk is called risk management. There's a whole discipline devoted to calibrating the amount of distress that certain kinds of dangers pose to people or structures. On a scale of intensity, natural disasters--such as hailstorms, tornadoes, tsunamis, hurricanes, mudslides, floods, fires, earthquakes, volcanic eruptions--all are empirically gauged on a curve of known effects. The more frequent such occurrences, the greater the likelihood that someone living in a high risk area will be affected. Degrees of severity also play a part. A small hailstorm in Nebraska may break a few automobile windshields, and penetrate a few cheap roof structures, but by and large it's more frightening, more curious, than devastating. A big hurricane, on the other hand, depending on its intensity, and where it reaches land, will always cause a lot of harm.
Nations and states and counties and towns all have to consider what the best policy should be, to protect their respective citizens from unnecessary risk. But how much preparation is practical, and how much merely speculative? Society tends to become preoccupied, at any given moment, with the death rates from disease, or from wars, or from terrorist acts, or from driving on the highway, or jumping from bridges or high buildings. The events of 9/11, for instance, were probably more destructive, in terms of human life, and in terms of structures, and in terms of ordinary peace of mind, than most earthquakes ever are--certainly in the U.S. Could 9/11 have been prevented? Could it have been mitigated by planning and emergency preparedness?
We're told over and over by "the authorities" these days, that all our building structures, our elevated freeways, our bridges, must be "retrofitted" to make them more stable, more secure against probable shaking in earthquakes. The costs involved in such "retrofits" is considerable. To retrofit a house, or an apartment building. or a city skyscraper--to make it more rigid and stable, to withstand greater degrees of eccentric movement--is very difficult.
Are such retrofits cost effective? In other words, is it in society's interest to expend large amounts of public and private money to prepare for an event that may be as far away from happening as a century or more?
As the world population continues to explode, the value of human life goes down. This may sound cold-bloodedly insane, but as a fact of life it's undeniable. Man's ability to over-run his environment has gotten completely out of hand. We hear of thousands and thousands dying of hunger and disease and civil unrest across the globe, and we hardly blink an eyelid. And as populations expand, more and more people are put "at risk" by inhabiting areas where the conditions exist for large events to claim the lives and work of millions. Global warming threatens to eliminate many of the largest port cities on the planet, as a result of rising sea-levels. And yet the nations of the earth are doing virtually nothing about this.
And yet, cities and counties and states are warned that if they don't retrofit all structures and services against the next big quake, armageddon will sweep thousands away, and wipe whole cities off the face of the map. What if all the money that we spend preparing for the next geologic event were spent instead on more immediate needs and purposes, based on the human time scale, instead of the geologic one? What is the price we're willing to pay for the fear we feel about imponderable geologic events such as earthquakes? Certainly there are sensible things we can do to "get ready" for probable dangers. Houses and buildings can be constructed with lateral bracing and lockdowns. Elevated passages can be built that will not fall down when shaken. Children can be taught to dive under desks. And you can put a jug of water, a few cans of pork and beans, and a good flashlight in the kitchen pantry. But in a practical human time sense, wasting society's resources to prepare for an event they may well not occur within our lifetime, or even that of our grandchildren, seems like a boondoggle for the contracting industry.
Let those geologists prognosticate and wave their hands in the air, presaging doom and gloom and the end of civilization as we know it. Great catastrophes which happen once or twice a century are interesting to contemplate, but common sense tells us that organizing our lives around such unlikely and infrequent events is silly. Some people aren't satisfied unless they've built a moat around themselves, and have a stock of weapons and emergency supplies handy at all times. They imagine a post-apocalyptic world where everyone or every family is on their own, living in a jungle of threat and competition. But this view is a fantasy. If society's history of response to crisis is any guide, disasters tend to bring out the best in people, and civilizations rebuild after great devastations. And what we do to each other in wars and disputes and neglect, far outweighs the harm done by nature. The pain and death and destruction we wrought on Iraq, for instance, is many times greater than any combination of natural disasters that could ever have happened there.