Google vs. Creationism
One of the claims made by young-earth creationists (YECs) is that the Grand Canyon was formed when the waters of Noah’s flood subsided; a whole lot of water drained off and carved a channel in the rock.
Geologists have known for a long time that this idea is ridiculous. For regular folks like me, though, Google Maps can help illustrate why it’s nonsense.
First, here’s a satellite view of the Channeled Scablands of eastern Washington. The town at the north edge of the picture is Coulee City, WA, next to the Grand Coulee dam.
According to mainstream geologists, the area south of Coulee City was formed by a gigantic flood. To me, this looks kind of like my basement floor after rains and a backed-up drain brought in dirt from outdoors and left rivulets of mud after the water drained away.
Now let’s take a look at a satellite picture of the Grand Canyon.
To me, this looks quite different from the previous picture. For one thing, the river meanders a lot. It is also surrounded by a fractal pattern of mountains (looks a bit like frost, doesn’t it?), something we don’t see on the Scablands photo.
I’m not a geologist, but to me this looks like what you get in simulations of drainage basins, i.e., when water erodes rock.
Excellent post! When one compares the resulting geomorphology of a know high volume, catastrophic flooding event like that which formed the Scablands with that of the Grand Canyon it is easy to see they are very different. Scablands is a morass of anastamosing, braided channels spread across a wide area. Similar bedforms are apparent in the Toutle River at St. Helens (much beloved as a source of creationist baloney-geology) The Grand Canyon is a single, sinuous channel with very strong meanders, very deeply entrenched. High volume floods simply do not create that sort of morphology. The kind of meander pattern seen in the GC more closely resembles that of the lower Mississippi. As anyone who has a good background in Sed/Strat will tell you, meanders form due to a low gradient decelerating stream flow resulting in lateral erosion. The Grand Canyon was the result of a low gradient meandering river course becoming entrenched as the plateau over which it flowed became uplifted. The process is know as stream rejuvenation. Another problem with the Noachian Flood model for the GC formation is the lack of an impounding structure and the associated widespread, time-synchronous lake bed deosits upstream. When it comes to sedimentology and creationism, denial ain’t just a river in Africa.
You lost me at “anastamosing”, “Sed/Strat”, “low gradient decelerating stream flow resulting in lateral erosion”, “entrenched”, “rejuvenation”, and “impounding”, but I gather that your general thrust (no pun intended) is that YECs who think Noah’s flood caused the Grand Canyon are full of crap.
Would you happen to have the Google Maps coordinates for a good representative view of the Toutle River? Hovind in particular loves to go on about Mt. St. Helens, so this might be a good addition.
Below is an over view of St Helens and Toutle River
http://maps.google.com/maps?ll=46.260594,-122.345810&spn=0.240381,0.492496&t=h&hl=en
Below is a closer view of the Toutle’s course
http://maps.google.com/maps?ll=46.316584,-122.472153&spn=0.120068,0.246248&t=h&hl=en
AIG and other creationists are completely full of crap when they try to use St. Helens as a model for rapid canyon formation. They are grasping at straws (and missing).
Anastomosing means dividing apart and coming back together. Most streams are dendritic (including the Colorado through the GC), that is they have the form of tree branches, tributaries form the twigs, flowing into streams, the branches, and into the main river, the trunk. Sediment laden rivers often become braided (anastamosing), with many separate and constantly changing channels that separate and run back together.
Sed/Strat is short for sedimentology and stratigraphy. Sed is the study of sediments, stratigraphy is the study of the layering of rocks.
The low gradient thing means that as a landscape become flat, rivers will expend their energy eating away at the sides of their channels (lateral erosion) because they can’t cut down much below base level (sea level). The same effect can be seen in train crashes. When a train hits something, the cars behind the locomotive will fold alternately left and right as they pile into the stopped part of the train. They are expending their kinetic energy laterally because they can’t go down underground or up because of gravity, so they go sideways.
Entrenched means just that, dug in. The meanders of the Colorado are at the bottom of very deep canyons, entrenched. The meander pattern was established first, then the river dug down.
Rejuvenation refers to the steepening (by tectonic uplift of a whole region) of the land through which a river flows. For example, if the lower Mississippi valley was uplifted and it still sloped towards the Gulf, It would begin to downcut its bed again, following its established meandering course. The result would be something along the lines of the GC.
Impounding is what a dam does to water. If there was to be a giant flush of water that formed the GC, that water had to be retained as a lake behind some sort of dam, which then would be breached, causing a catastrophic flood. The problem is at the GC there is no dam and no evidence of a vast lake. These sorts of evidence are very apparent at the head of the Scablands.
OK, one last point. If there was a massive flood that carved the GC, where did all the sediment go? The vast amount of material generated would not stay suspended but would settle out quickly as the current decelerated even slightly, causing the braided condition common to sediment -choked streams. Where the hell is the sediment?
Um… with the missing socks? Well, it seems as if the turbulence from a half mile high wall of water could keep a great deal of sediment suspended for some time, but I am no geologist nor a fluid mechanics engineer. How much sediment are we talking about? I read an interesting piece about a meteorite strike where the depth of the crater was smallish, maybe fifty feet, but the diameter was large, say fifty miles. At first glance one would surmise that the crater wasn’t deep enough. But, when the math was done it turns out that the amount of ‘earth’ displaced by such a crater was massive, indeed. So, could the sediment have been distributed over many square miles ‘only’ a few feet thick? That would represent a huge amount of matter.
Pete Anderson,
As a rough, first order derivative back-of-envelope guesstimate I’d say about enough sediment to fill the Grand Canyon.
I’m still giggling at your profound answer. Very good sir!
Why are we discusing creation as an issue. the earth did what the earth did! that’s it. Google shoul stop fearing what the earth did as an arguement for sombody’s point of view on Religion! Just present the data, and let the chips fall.