Probably the best field trip I have ever been on is the one I took to Washington State in September 2002. We spent a day at Mount St. Helens and studied the enormous volcanic deposits known as the Columbia River Flood Basalts, but by far the best part of the trip was our study of the Channeled Scablands of eastern Washington. (Here you can find pictures and other info on the particular trip that I took, from some other people at LPL.)

The Scablands are a unique terrain characterized by enormous dry valleys (known as coulees), giant gravel bars, giant current ripples, hanging valleys, "scabland terrain" riddled with potholes, and other features. These were formed by the "Missoula Floods," which took place 13,000 to 18,000 years ago, during the Ice Ages, when a 1/4-mile-high ice dam in western Montana failed. The resulting torrent had a discharge rate as high as 20 million cubic feet per second!! The water reached depths as high as 250 meters, and speeds as high as 30 meters per second (68 mph). "Dry Falls," pictured at right, is 3 times as high as Niagara and 3.5 miles wide!

The Scablands have been an important catalyst in convincing the scientific community that Uniformitarianism (the idea that only gradual processes are important in geology, and that giant "catastrophes" never happen) is not useful when taken as a dogma. A rigorous definition of Catastrophism might be that extraordinary events (generally unusually large events) create more changes in the terrain than the summed-up effects of all gradual processes, even if those gradual processes persist for millions or billions of years. There is now broad acceptance that, although uniformitarian processes are still important in most places on Earth, catastrophes are sometimes the dominant driver of change and cannot be ignored: for example, the impact of a Mars-sized planet with the Earth that is thought to have led to the formation of the Moon, and the extra-terrestrial impact thought to have killed the dinosaurs. The Missoula Floods are a more recent example, but still a spectacular one.

It is just as much of a mistake, however, to assume that only catastrophes are important. The Missoula Floods have no connection with the book of Genesis. If they did, you would expect terrain like the Channeled Scabland to be very common all over the earth, and not the rare and extraordinary feature that it is. Actually, the Channeled Scablands are a powerful argument against those who claim that the Grand Canyon (for example) was formed by catastrophic processes connected with the Biblical Flood. We know what it looks like when canyons are excavated by catastrophic floods, and it looks like the Scablands, not like the Grand Canyon: 1) you see many channels, as the flow is too large to be carried in a single channel; 2) you see evidence of water spilling over ridges from one valley to the next; 3) you see large areas of potholed "scabland terrain," formed by the great turbulence of the water flow; 4) you see giant gravel bars due to the enormous amount of sediment carried by such a flow; 5) you see ripples (think about the bottom of any sandy stream) four stories high and two football fields in wavelength, due to the great speed and depth of the flow; 6) you see hanging valleys and waterfalls, as the main canyon is excavated far deeper than it was when the side valleys were formed; 7) you see boulders many feet across that have been removed miles away from their source; 8) you certainly do not see buttes and peaks in the middle of the canyon, as everything is carried away by the torrent. None of these things are true of the Grand Canyon, leading to the conclusion that it was gradual processes over many millions of years that are responsible there.

The field trip that I took was led by one of the world's authorities on this type of giant flood, who also happens to be a professor in the Planetary Science department here at UA. He edited a book on the region (and also wrote about half of it), which is still the definitive work on the subject. Unfortunately, the book is out of print, and although Dr. Baker loaned me a copy for the trip, he wanted me to give it back. So, using a scanner and the work of someone else who had already scanned much of the book, I made a PDF file of the book which can be printed. So now I have a copy to keep, and any of you who are interested can have one too (Dr. Baker tells me the book was never under a copyright, being an internal NASA publication). Here is the website I have set up for downloading the PDF file.

The Channeled Scablands are an incredible reminder of the power and grandeur of God's creation. As with everything in nature, I believe that studying them (even if we come to conclusions that don't fit comfortably with our pre-conceived notions) helps us to better understand and draw close to God.  

Posted by Matt on 4/30/2004 12:25:00 PM