Young-Earth creationism and the intensity of volcanism
The June 2012 issue of the Institute for Creation Research’s Acts & Facts magazine came to my mailbox this week, and the short article “Volcanoes of the Past” by John D. Morris caught my attention. The article argues that Noah’s flood was a time of massive volcanic eruptions (“supervolcanoes”), and that volcanic activity on Earth is now experiencing a rapid post-Flood decline.
The cornerstone of young-Earth creationist (YEC) geology is the belief that Noah’s Flood was global in extent, occurred sometime around 2300 BC, and is responsible for most of Earth’s geological features. For a variety of reasons that I have discussed elsewhere (here, here, and here for example), I don’t think that any of this is Biblically necessary nor scientifically viable. A corollary of this “Biblical Catastrophism” or “Flood Geology” is that the catastrophic activity of Noah’s flood continued after the deluge, but with exponentially declining intensity over time. According to this theory—which is not held by all YECs—the centuries after the Flood were chaotic times, with rapidly changing climate (including a single ice age), rapid sedimentation, and biological diversification. According to some, much of Earth’s Cenozoic record was deposited during these few short centuries. The difficulties with this scenario are almost as numerous as the problems with YEC flood geology, but I won’t get into that now.
The heart of Morris’s argument is that we see evidence of massive “supervolcanoes” in the rock record, and that we don’t have any of these erupting today, which is a true statement. Furthermore, if one plots the volume of material extruded by historic volcanoes, one sees a decline over time. This statement is quite simply not true. In his own words,
Through an understanding of today’s volcanic eruptions, we can better comprehend those of the past. However, the rock record of the past suggests that yesterday’s volcanoes were evidently “supervolcanoes,” accomplishing geologic work hardly comparable to those we currently observe.
If we plot the volume of ash and lava extruded by volcanoes throughout history—comparing Vesuvius (79 A.D.) and Krakatoa (1883) to more recent volcanoes, such as Mount St. Helens (1980) and Pinatubo (1991)—we come to the conclusion that the earth processes are quieting down. Then if we plot the materials blown out by volcanoes that erupted during the great Flood and soon thereafter (inferred only from the materials left behind), then we conclude an exponential decline in the power of earth’s volcanoes over time. Flood volcanoes were many times greater than those recently witnessed.
The article includes a graphic showing volumes of volcanic products from several eruptions, with an obvious decline from the Huckleberry Ridge Tuff from the Yellowstone (Island Park) eruption (2500 km3), down through Mount St. Helens (a mere 1 km3).
A person with little or no geological background reading the article and examining the figure could only come to one conclusion: There has been a steady decline in the intensity of volcanism on Earth. There are a number of problems, however, with Morris’s article.
First, Morris’s graphic is rather deceptive, especially given the content of the accompanying text. These five eruptions are portrayed from oldest to youngest, and from largest to smallest. What the diagram doesn’t show, however, is that there are many thousands of volcanic eruptions throughout the same time period which don’t fit the YEC post-Flood residual catastrophism model. The following graphic from the US Geological Survey gives a much more realistic depiction of the variability of volcanic intensity over time:
This USGS diagram is highly selective as well, as it lists only a handful of eruptions, but it is much more representative of actual trends. The Holocene (Recent) Epoch—which all YECs would consider post-Flood—has a history of a wide range of volcanic eruptions, ranging from very small to large eruptions such as that of Tambora in 1815 and Mount Mazama approximately 7700 years ago. There is no evidence that I know of that the frequency or intensity of any eruption type is decreasing with time. Instead, smaller eruptions are occurring almost continuously around the world, while the larger eruptions occur with frequencies measured in centuries or millenia.
Morris named four historic eruptions as part of his evidence that volcanism on Earth is slowing down.
If we plot the volume of ash and lava extruded by volcanoes throughout history—comparing Vesuvius (79 A.D.) and Krakatoa (1883) to more recent volcanoes, such as Mount St. Helens (1980) and Pinatubo (1991)—we come to the conclusion that the earth processes are quieting down.
These four eruptions—out of thousands he could have chosen—don’t even illustrate the trend that Morris is advocating. Rather than going from larger to smaller, the trend makes a zig-zag:
One could selectively choose four or more eruptions to show any trend they wanted: increasing volume, decreasing volume, steady volume, or random. It would be far better to look at thousands of eruptions over a long period of time, and Morris has not done that.
The second problem I want to mention is that the eruptive history of the Yellowstone region is far more complex than Morris implies. The figure in the article shows the products of two Yellowstone-related eruptions: the Huckleberry Ridge Tuff and Lava Creek Tuff. There have actually been three large eruptions from the Yellowstone area:
- Island Park Caldera, Huckleberry Ridge Tuff, 2.1 million years, 2500 km3
- Henry’s Fork Caldera, Mesa Falls Tuff, 1.2 million years, 280 km3
- Yellowstone Caldera, Lava Creek Tuff, 0.6 million years, 1000 km3
The trend is from largest to smallest to something in-between. Again, Morris selected the two eruptions that supported his thesis and ignored the other eruption.
But there is much more to the story of Yellowstone. In between the mega-eruptions, and in the time since the most recent, Yellowstone has had numerous smaller eruptions of rhyolitic and basaltic lava. Therefore the trend in Yellowstone is really mega-small-mega-small-mega-small. But there is more: the Yellowstone volcanic area is part of a string of volcanic centers that extend from northwestern Nevada through the Snake River Plain up to the area of most recent explosive activity in Yellowstone. There have been dozens of “supervolcano” eruptions along this trend, with hundreds or thousands of smaller eruptions in between.
A third problem with Morris’s article is that the more ancient rock record isn’t just a history of supervolcanoes. Throughout Earth history there have been large volcanoes and small volcanoes. The large volcanoes include explosive “supervolcanoes” such as Yellowstone Caldera, Long Valley Caldera, and Toba, Indonesia; and also flood basalts (the term “flood” has nothing to do with Noah’s flood) such as the Columbia River Basalts. But throughout the same time period there have been numerous smaller eruptions, whether from stratovolcanoes such as Mt. Fuji or Mt. Rainier, or from even smaller volcanoes such as cinder cones and maars.
It is clear that there is no trend in Earth history going from larger volcanic eruptions to smaller. Young-Earth creationists might counter by saying that it is still a fact that there have been massive volcanic eruptions in the past, and that none of these are occurring today. The standard geological explanation is that the larger the eruption, the greater the time gap between eruptions. Yellowstone apparently erupts every 0.6 to 0.9 million years; we may be due for an eruption, but it could still be hundreds of thousands of years away. These eruptions are spaced too far apart to say whether or not their frequency is changing over time.
The YEC has a greater problem, and that is trying to fit a large number of very large eruptions into a very short time. If the Yellowstone eruptions occurred after the Flood (the distal ash is in what most YECs would call post-Flood deposits), then three very large eruptions had to occur in the span of a few centuries perhaps just a little more than 4000 years ago. In between these eruptions there would have had to have been time for weathering, vegetation growth, and a number of smaller volcanic eruptions. All of these volcanic deposits would have had to be emplaced in time for the Ice Age, which lasted only a few hundred years. And all of this is a gross oversimplification of everything that would have had to have happened in a very short period of time.
Unfortunately, most Acts & Facts readers will be completely unaware of the numerous weaknesses in this article. Morris has not made a case that the frequency or intensity of volcanism is decreasing with time.
With love for my YEC brothers and sisters in Christ, and with prayerful concern for those who are turned away from Christianity by bad arguments in defense of the Bible.
Grace and Peace
P.S. This post-Flood residual catastrophism concept actually has led to one of the best papers to come out of the YEC movement, Earthquakes and the End Times, by Austin and Strauss. A common claim among end-times prophecy teachers is that the frequency and intensity of earthquakes has been increasing over time, leading up to the return of Christ. Austin and Strauss refute this teaching, calling it a Christian urban legend. One impetus behind the article, aside from the fact that there is no geological evidence for an overall increase of earthquake activity on Earth, is this YEC idea that intensity of all sorts of geological activities should be declining over time. I briefly discussed the “Earthquakes and the End Times” article back in 2007 (here).