“CATASTROPHIC” EVENTS IN A
. . . The late 18th and early 19th centuries, when the study of the earth was first becoming a science, was a period marked by a long battle between catastrophists—who thought that sudden great events were crucial to the evolution of the planet—and uniformitarians—who explained all history in terms of gradual change. —Walter Alvarez and Frank Asaro1
[Evolutionists] hold that the present conformation and composition of the earth’s crust, the distribution of land and water, and the infinitely diversified forms of animals and plants which constitute its present population, are merely the final terms in a an immense series of changes which have been brought about, in the course of immeasurable time, by the operation of causes more or less similar to those which are at work at the present day.—Thomas Henry Huxley
The fundamental idea is that geological processes such as wind, flowing water, waves, and floods, worked in the past much like they do today.—Darwin Spearing2
… I have no objection to this interpretation; gradualism, after all, is not uniformity.—Milford Wolpoff3
I live in Missoula, Montana. My house is on a hillside about 100 feet above the valley floor on the southwest edge of town. I can see the Clark’s Fork (of the Columbia) and Bitterroot Rivers. Before they built the houses behind me, I had a good view of the upper hillsides on the east edge of town. I could see the parallel lines that run across the slopes, especially in the spring when the snow had started to melt. The highest of the lines is about 1000 feet higher than my house. The “lines” are prehistoric beaches from Glacial Lake Missoula. The soil under the grass around my house is fine silt with numerous (and I do mean numerous) water-worn pebbles and cobbles left by the lake and the icebergs that floated on it. When I drive west of town on the interstate there is a road cut that exposes alternating deposits of lake bed deposits and river sediments, some 36 cycles of the lake filling and draining. I have also been across eastern Washington a number of times. I have seen the potholes, the Channeled Scablands, and the Dry Falls. Glacial Lake Missoula formed about 10-15,000 years ago during the last glacial advance when a tongue of ice advanced from Canada and across the the Clark’s fork River at the future Idaho-Montana border. This ice dam backed water up into the valleys of western Montana forming a vast lake until the water either floated the ice up or flowed through cracks in the ice causing the ice dam to fail catastrophically, sending a huge flood of water rushing downstream through the Columbia River to the Pacific Ocean. After the flood the ice would advance and again block the river, repeating the cycle over again, multiple times over several thousand years. All around me is evidence of “non-normal” catastrophic geological events.
When Charles Lyell published his Principles of Geology in three volumes beginning in 1830 he ended an ongoing debate between two schools of geologic thought. On the one side were the “Catastrophists” who believed that the earth was periodically torn by immense forces that completely altered the surface of the earth and destroyed all or nearly all life. Afterwards new life was created to repopulate the earth until the next catastrophic event. With each catastrophic destruction and subsequent creation, the earth and the life on it progressed to a more advanced state, i.e. more like the present earth and life forms. These periodic catastrophic events were caused, directed, and controlled by a supernatural force, (the Christian’s God). The Biblical Genesis and the Noachian Flood were merely the last of along series of catastrophic destructions and creations.
Opposing them were the “Uniformitarians.” Uniformitarians argued that all the changes shown in the geologic and fossil records are caused by forces generally similar to those observable today. All the change was due to those natural forces gradually working over immense periods of time. Lyell’s books pretty much ended the argument in favor of the Uniformitarians. (The argument still continues, Creation Science is still using the Catastrophist’s ideas and arguments).
Like so many things we humans do, Uniformitarians emphasized the “gradualism” and the lack of catastrophic events in their theory to separate and distinguish themselves from the Catastrophists. Over time this emphasis hardened into a belief that only the small, gradual forces we see today were at work. There were no catastrophic events allowed and nothing that even hinted at “catastrophic” (from a human perspective) would be considered to be possible. Even to the extent that large circular structures on earth that looked identical to meteor craters on the Moon were believed to have some other cause.
However “catastrophic” events have reappeared as possible geologic agents (e.g. the K-T impact). Uniformitarians have been accused of becoming Catastrophists (usually by Creationists who then claim that this “proves” they are right). There is, however, a vast difference between the catastrophes invoked by the Catastrophists and the catastrophes of the Uniformitarians.
Catastrophists argued that all change was caused by supernatural forces acting over a short period of time to completely recreate the world. These forces were not explainable by natural causes. In the sense that miracles4 can be defined as a violation of the laws of nature, these were miracles. There is not enough water on earth to flood the entire world. Even if all the ice in Greenland and Antarctica melted the earth would not be completely covered, most of the major cities of the world yes, but not the entire earth. Where the 40 days of rain came from and where it went to cannot be explained by natural causes. The causes of Noah’s Flood are in the realm of miracles. God, being omnipotent, is not constrained by natural law and can violate them when and how He desires.
Catastrophes of the Uniformitarians are not the miraculous, supernatural, and world-destroying events of the Catastrophists. They are natural events, the result of natural processes. Uniformitarianism is not exactly equal to gradualism either, if gradualism means small events occurring at low levels with small effects accumulating over long periods of time. Uniformitarianism is just using known natural processes which will vary in size and intensity to explain the geologic record.
“Catastrophes” are admissible cause in the uniformitarian theory, given enough time the improbable random event becomes statically certain. Where Catastrophists have gone astray (and Uniformitarians, too) is believing that since “nothing” happens that they can see that therefore “nothing” ever happens for millions of years. One day is like the next, the rivers still run in their beds, no deeper than before, the mountains are just as high as the day before, there are no volcanoes exploding, no seas encroaching on the land, or land rising out of the sea, therefore these events are not normal and never happen in the normal course of the aeons.
Catastrophists carry this to the point that there is no erosion, etc. at all until one day everything breaks loose: mountains are thrown up, or ground down, seas rush in or out, volcanoes erupt and earthquakes rip the earth. These catastrophic events continue for an undetermined length of time (very short though) then cease and tranquility and stability resumes for millions of more years in the altered landscape, static and unchanging.
Uniformitarians argue that all these forces are at work in the present time, but in increments so minute as to be barely noticeable in a human life time. That was the original concept. It has been altered some to say that generally the forces are very minor but that there are times that the magnitude is increased drastically. There are earthquakes constantly but most are never noticed except by seismographs. But then there are the occasional earthquakes that do cause noticeable alterations in the landscape. While this is catastrophic on the human scale it is but a minor twitch world-wide. Uniformitarianism does not rule out massive alterations in the world, it merely says that the forces used must be natural ones, maybe of a different order of magnitude to what we are accustomed to, but not “supernatural” forces. The Ice Ages are an excellent example of the differences. The reason has not yet been determined, there are a number of competing theories. A leading theory is that naturally occurring cyclical changes in the Earth’s tilt, precession of the equinox, and orbital eccentricity, caused a shift in either temperature and/or winter precipitation. The result was that a few more snowflakes fell each winter than melted each summer. The snow fields grew to glaciers and the glaciers into giant ice sheets, snowflake by snowflake. The Catastrophists argued that it just started snowing one day, for reasons we will never know, and it snowed and snowed, the temperatures dropped and stayed. The glaciers held the world in their icy grip and then suddenly it all reversed itself, the snow quit, the temperatures rose and the glaciers retreated, suddenly.
It’s not that Uniformitarians argue that catastrophes are impossible (at least, they shouldn’t) but that before you accept a “catastrophic event” as the cause of some observed fact you have to rule out all the other possible causes.
Comets or asteroids colliding with the earth area an acceptable natural event. They are present in space, their orbits do cross that of the earth’s. Therefore they must from time to time collide with the earth. Anyone who watches the night sky will tell you that it happens frequently each night. Mostly the meteorites are small because most of the particles in space are small; occasionally a bigger one enters the atmosphere, because some of the particles are bigger. There are some really big “particles” drifting about in space and to say that they never have and never will collide with the earth is ridiculous. Statistically in the 4.5 billion years of the earth’s existence some very large asteroids and comets must have hit the earth. There are the remains of several impact craters visible on the surface of the earth. Most likely they had no more effect than when Krakatoa or Mt. St. Helens exploded. But the possibility (indeed probability) exists that at least once an extremely large body, large enough to affect the entire world in a single “catastrophic” event did collide with this planet (the K-T or Cretaceous-Tertiary Event 65 million years ago). But all other possible “uniformitarian” causes have to be ruled out first.
All geologic events run from the small and every day garden-variety type to the extremely massive, “catastrophic,” once-in-blue moon event (2.5-3.5 quakes to 8.4+ quakes, daily “dirt particle” erosion to mass wasting). In our life time/written history we have seen some large events. Even larger events are quite possible, extremely unlikely in the time of a life span, but in geologic time quite probable.
It is a matter of scale—a 10-mile asteroid is “simply” a large and rare meteorite, asteroids exist is a graded series of sizes from “micro” to very, very large. Small is the most common size and therefore the size most likely to collide with the earth. The larger, and rarer, an asteroid is, the less likely a collision. Less likely, not impossible. These things exist and they vary in size,we are most familiar with the smallest (just watch the night sky). But big ones have occasionally struck the earth. We have the craters to prove it (oh sorry—impact structures).
It is a big step to say that the average time between major impacts is ≈26my and that since there is an average of ≈26my between extinction events that impacts cause extinctions. (Which came first? Did Raup statistically determine the probable average time between large impacts first (and if so what parameters did he use to define “large impact”) or did he figure an average between extinction events and adjust his parameters for impacts to get a similar answer?)
It is also a difference of first “opinion” as to the cause. Catastrophists find a “discontinuity” in the rock record and look for a catastrophic event to fit it. Uniformitarians find a “discontinuity” and look for a “common” event that could explain it, expanding the search to bigger and bigger events until one fits all the known facts. You start with the most common events that may explain the facts. If none of them quite fit, less common events are looked at. If none of these fit the known facts then the extremely rare and “catastrophic” events (all though still a “natural” event) become acceptable cause, if they fit the facts better than lesser events. Uniformitarians start “at the bottom” with the most common occurring events, working up to the “least disastrous” event that fits. Catastrophists start at the top and tend to see everything as caused by world-altering catastrophes, confusing the lack of observable change in their lifetime as evidence that “stasis” is static. They do not comprehend that all these small and nearly invisible daily/seasonal events accumulate over geologic time scales with tremendous effects and become the mass of the geologic record. The effects are “catastrophic” in accumulation but are unnoticed because of their very slow rate.
By way of example, if you go to Cody, Wyoming you can drive on west of town on the road up the North Fork of the Shoshone River (heading for Yellowstone N.P.). A few miles out of town you drive through a canyon, through several tunnels, past the Buffalo Bill Dam, and to where the canyon opens out to a wide valley. Just as you come out of the last tunnel there is a parking lot on the left (south) side for the visitor’s center at the dam. You can park here and look across the reservoir to the canyon wall on the other side. There is a narrow and steep cleft in the rocks of the canyon wall. It rises out of the reservoir waters and goes up the mountain side as far as you can see. If you look at the rocks on both sides of this cleft you might notice that they are not the same from one side to the other. It may not be obvious to you but this is a “fault.” Not a “mistake” but a fracture in the rocks along which movement has occurred, movement as in earthquake. I first saw this fault nearly thirty years ago during a field school in geology, as I recall the total movement along the fault, the “displacement,” is several hundred feet. That’s why the rocks don’t match. One side of the fault dropped down and/or the other side rose upward those several hundred feet relative to the opposing side.
Catastrophists and Uniformitarians would interpret this in two different ways. A Uniformitarian would think: most earthquakes are small, the biggest we have experience of result in movements measured only in tens of feet. It is likely that earthquakes far beyond our limited experience are possible and they could cause a displacement that was several times more the largest now known, say 75-100 or even more. Several hundred feet of displacement in a single earthquake is theoretically possible, statistically a once in a geologically long time chance, but still probably not impossible. Since we believe that the laws of physics, etc. in the past are the same as operate now the fault is not a single earthquake but a series of small and large events whose total net movement is several hundred feet. These events happened over an extended period of time with long intervals between them. They happened the same way earthquakes do today along any active fault line, and we can understand what happened in the past.
The Catastrophist thinks: that was one really big earthquake, sure glad we have only little ones now. The Catastrophist approaches the problem with the idea that what happened in the past has causes different than the present. The past is different from the present and is not understandable.
1Walter Alvarez and Frank Asaro (1990:84). An Extraterrestrial Impact. Scientific American 263(4):78-84.
2Spearing, Darwin 1995. Roadside Geology of Louisiana. Mountain Press Publishing Company, Missoula, Montana. 1995:X-XI
3Wolpoff, Milford, 1986 Stasis in the Interpretation of Evolution in Homo erectus: A Reply to Rightmire. Paleobiology 12(3):325-328.
4 “Miracles are by definition arbitrary violations of the normal laws of nature and as such cannot be studied by the methods of science. To admit to their occurrence in order to explain the origin of certain structures in the world is to concede that a phenomenon lies forever beyond our comprehension—unless we accept the dictates of supernatural revelation.” (Bowler, Peter J. Evolution: The History of an Idea. University of California Press, Berkeley, 1989:7)