Friday, June 27, 2014

When a hot spot hiccups

The ground beneath your feet is not stable.

 No, I'm serious. You see, the continents and the crust below the ocean are floating on molten rock below them. And when these plates run into each other and start fighting over which one should be forced under the other, they have the potential to form earthquakes and VOLCANOES! This is how you get Mt. St. Helens.

 But believe it or not, that one was little. Larger volcanoes are caused by something very different. In the molten rock below the crust, there are a few spots that are hotter than others, aptly named hot spots. They build up pressure below the crust that they are below, and finally when the crust can't hold on anymore, they hiccup. 

 When they are below the ocean, it isn't a big deal. Oceanic crust is made of a material that just kind of melts, gives way a little bit, and flows up to form an island. And then as the plate moves over the hot spot, a chain of islands form. This is how Hawaii formed, and why only one of the islands is still an active volcano. And why people can inhabit that island without really worrying about getting blown away.

 But then once in a rare while, they end up below the continent. And when that happens, they form super volcanoes, and the crust is a type that likes to hold on to gases as long as it can before it finally explodes. Everyone's favorite example is Yellowstone. It turns out that when Idaho was over that same hot spot, it went off and formed the little shards of glass (also known as ash) that would bury everything and become Ashfall.
But why glass, people ask? Glass is man-made, isn't it?

 Well, yes. You're windows that are made very nicely in a controlled environment are, anyway. But man has a habit of making use of natural processes. You see, if you have ever had the chance to see how glass is made (at least how it was made in the early days of glass making), it basically consists of blowing a bubble of super-heated sand or rocks with a lot of silica in them. And in an environment that isn't controlled, its like watching a little kid blow a bubble out of gum. It gets bigger, and bigger, and then POP! It explodes. Especially in volcanoes that are underneath continents, because they are basically MADE of silica. 

 And what about Yellowstone? Could it happen again? Well, yes. But one the size of Ashfall wouldn't happen in our lifetimes. In fact, the last one that went off from the hotspot was smaller than that. And the eruptions aren't actually as much like clockwork as the media would have us believe. Geologists are monitoring the spot, and while it is active, it is a long way off from having enough pressure to blow. If it were to, it wouldn't even classify as a hiccup.

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My Story (Very briefly...)

Lots of people claim that they wanted to be paleontologists at the age of 3. So did I. The problem is, I never really grew out of it. My third birthday party had dinosaurs. Everywhere. I grew up digging in fossil dirt from Aurora, NC, looking for coral and shark teeth. I practically lived at my local science museums (and still do, only now I get to do research, fossil preparation, and work in collections!) When local paleontologists discovered a dinosaur with a "fossilized heart" (no longer considered such) when I was little, I got to meet the man who led the work. And then, years later a dinosaur bone with soft tissue turned up. I was officially hooked.
No longer was I dreaming about dinosaurs. I was actively pursuing the science behind prehistoric creatures. I didn't want to read about it, I wanted in on the action. So I started working at the museum, and finally going on my own adventures. And thus, I needed a place to share them and maybe inspire others the way I was inspired. I have gone from watching fossils be prepared from one side of the glass at the museum to working on them on the inside of the glass. I am a student working toward my goal. I can finally start to call myself a paleontologist.