Saturday, June 13, 2009

Plate Tectonics: A Primer

I generally don’t do this, but this week a random conversation started up in the comments to my last After the Flood post. The issue at hand was evidence -- or, more appropriately, lack of evidence -- for a young Earth. After Da Bomb claimed he could offer evidence for Noah’s Flood, I challenged him to explain where all the water went. He offered this: “I thought this was interesting. http://www.christiananswers.net/q-aig/aig-floodwater.html.” I started to write a reply that’s turned out to be quite long, so I’m instead exercising my right as the guy who runs this blog and making a whole new post. So here we go… Um, I do hope you realize that any time you try to offer evidence for anything science related from Answers in Genesis you're not going to be taken seriously. But the article in question is easy enough to deal with. The article basically argues that there were no real surface features and that god lifted up the mountains and whatnot over the course of the flood in order to give them a place to drain. Yet we have absolutely no evidence of sudden, catastrophic planetary changes like that. What we do have is plenty of evidence to back up plate tectonics, which is indicative of gradual changes over time according to measurable, natural mechanics. What all the evidence points to is continental drift. Millions of years ago there was a giant supercontinent called Pangea that split apart. The Earth's is not a single, immobile piece of anything. It floats on top of what can be called, for lack of a better term, a sea of magma. There are also seams in the crust. The areas around those seams are constantly in flux. Some are expanding, some are contracting, and some are grinding past each other. Given these three types of plate movement and the theoretical supercontient, we should be able to expect to see a few things. First, we should expect to see some of the Earth's features that stretch across several continents. We have found that. The Appalachian Mountains, the island of Nova Scotia, the Scottish Highlands, and the mountains of Norway are all part of the same exact system. Go here and read the footnote. David Morgan-Mar explains it way better than I could. There's a similar formation where we know that the east coast of Brazil was joined to the west coast of Africa. Meanwhile, there aren’t any similar features between, say, China and California. This is because the point of expansion is the Mid-Atlantic Ridge. So the Americas are slowly drawing away from Europe and Africa and drawing closer to Asia. If we can wait a few million years, in fact, we’ll be able to see the formation of a new supercontinent as the Pacific shrinks to nothing. Second, we should be able to see evidence of rock formation and/or destruction on the edges of the plates. We can. The Mid-Atlantic Ridge is a giant mountain range in the middle of the Atlantic created a little bit at a time as magma pushes up through the center, gets to the top, and cools. On the other side the Pacific Plate is a subduction zone. As the North American Plate pushes against it, the Pacific dives underneath, where the rocks melt and basically allow for the cycle to start all over again. I find this video kind of annoying, but it’s a good primer. Back in the day I saw a video during an Earth Sciences class where they actually ran a video camera past the Mid Atlantic Ridge and watched magma flow up and cool. Sadly, I don’t remember what that video was called. Third, we should see consistent features around the edges of plates. Out in the Pacific Ocean there is an area known as the Ring of Fire, where volcanic activity is extremely high. When we look at the Ring of Fire we’re actually looking at the borders of the Pacific Plate. One of the best known features of the connection between the Pacific Plate and the North American Plate is the San Andreas Fault. This is what is known as a transform boundary, where the plates aren’t converging or diverging, but grinding past each other. Most of the time they more or less slide past each other. Every once in a while they get stuck and energy builds up at the boundary. When that energy is released we get earthquakes. Meanwhile, we don’t get that many earthquakes in, say Illinois, since there isn’t a transform fault anywhere nearby. Meanwhile, the Pacific Plate offers us further evidence of the movement of plates. Some volcanoes don’t form around plate boundaries, but over “hot spots” in the mantle where the Earth’s crust is locally thinner. We tend to see hot spots in the ocean, since ocean crust is much thinner than continental crust (for what I hope are obvious reasons). One of the best known hot spots is the chain of islands we call Hawaii. All of the Hawaiian Islands were formed from a single hot spot that pushed the islands up as the plate passed over. Now, then, what does plate tectonics have to do with mountains? You’ll notice that most mountains exist in ranges. The ones that don’t are generally volcanoes, too. The Rocky Mountains in North America arose due to compression of the continental plate. The Himalayas rose as the result of the collision between the Indian Plate and the Eurasian Plate. The Himalayas are still growing, since the Indian Plate is still moving north. The Rockies, on the other hand, are shrinking ever so gradually, since the forces that created them are no longer in effect and the main force active against them is erosion. Either way, the Rockies and the Himalayas have been around for 50 to 70 million years or so. So there you go. There are actual explanations for things. Answers in Genesis is an oxymoron…

6 comments:

Da Bomb said...

http://www.cs.unc.edu/~plaisted/ce/flood.html

This may be food for thought? At least it is evidence...

"Evidence in its broadest sense includes everything that is used to determine or demonstrate the truth of an assertion..."Evidence is the currency by which one fulfills the burden of proof." (wiki)

Geds said...

You have a weird definition of evidence. You also shifted the goalposts. I'm about to move my estimation of you from "uninformed" to "willfully ignorant." Take that as fair warning.

First off, we weren't talking about sedimentary layers. We were talking about mountains. When I offered plate tectonics as a scientific explanation for the existence of mountains, you moved to sedimentation. Even though you moved from one wrong-headed explanation to an equally wrong-headed explanation, you're not really helping your cause by moving in the first place. All you do by shifting the field like that is reveal to everyone your lack of ability to offer any refutation of science beyond shallow, incorrect, easily debunked articles.

I do like the way the person in your link tried to hide the standard "The Flood Did It!" behind a scientific sounding term like "Liquification."

Either way, I'm no geologist, so I don't have to use info from my Earth Sciences courses every day of life. However, I know enough to know that the entire article in your link is full of shit. Its basic claim is that science's explanation of the formation of sediment is wrong because the author says it's wrong and the better explanation is a global flood because the author says so.

Also, I love this: "Fossils are sorted vertically to some degree. Evolutionists believe this is a result of macroevolution. The mechanism by which macroevolution could happen is not understood, and many evidences refute it."

First of all, fossils are sorted vertically, period. There is no, "To some degree involved." That's how we can date the existence of various sorts of creatures so accurately. You don't find a whole crapload of pre-Cambrian fossils hanging out with Jurrasic fossils and you don't find Allosaurus bones with Neanderthals. Second, the mechanisms of evolution are well understood and thousands of books and articles have been written about them. Any claim to the contrary is pure ignorance and those who make arguments to that effect should be escorted from the discussion immediately.

You've now thrown an Answers in Genesis article and this pile of rubbish at me. Get me some actual science that refutes the explanations for evolution or sedimentation and we'll talk.

But until then, go read up on the geologic record and sedimentary rock structure. You might learn something

Da Bomb said...

"I'm about to move my estimation of you from "uninformed" to "willfully ignorant." Take that as fair warning."

Thats fine :)

I do not know a lot...I admit that, but for me it is comparing your word against others. I don't trust atheists in general, though some tend to be sinserely thinking people.

"Either way, I'm no geologist"

Another reason why I question some people's refutations.

"Now, I suppose you could point out that he could be referring to the Jewish god. But Cooper’s not trying to argue for Judaism and the Jewish god doesn’t look a damn thing like the Christian god."

And this quote from the last post of your's...Jewish God not like the Christian?

Rubbish.

A statement like that is reason why I cannot trust your word.

Our conversations seem to be pointless. Sorry for wasting our time.

Though thankyou for taking the time to chat :)

Geds said...

I do not know a lot...I admit that, but for me it is comparing your word against others. I don't trust atheists in general, though some tend to be sinserely thinking people.

Then please, feel free to leave and never come back. You have officially worn out your welcome. Your rhetorical style of ignoring everything I say in favor of posting stupid, ignorant articles written by people who don't know the first thing about science and then saying, "Food for thought," is extremely annoying and unhelpful. Also, doing that and then saying that you don't trust anything I say anyway simply proves that you are a willfully ignorant ass who wasn't attempting to learn anything and never will.

So bite me.

And this quote from the last post of your's...Jewish God not like the Christian?

Rubbish.


Really? So you can't read the Jewish Bible (known to self-centered Christians as the "Old Testament") wherein god is commanding the death of every non-Jew on every other page and the Christian Bible where god is all about self-sacrifice and sending that message far and wide across the planet and think, "Hmm, maybe there are two different attitudes about the world at play here?" Because that's one of those key things that caused me to decide not to go to seminary and then to stop going to church and stop calling myself a Christian.

Our conversations seem to be pointless. Sorry for wasting your time.

There, fixed that for you. You should be sorry for wasting my time.

Anonymous said...

Self-centred cock end. Most people think a daddy long-legs is a flying insect. Just because they'll argue it to the death does that mean you should believe them?

Anonymous said...

Wow, I went back in time to say that.