Sunday, May 10, 2015

How do you science? with dynamite!

- Alison

So what do we do?


To start out I wanted to give you a brief introduction to what it is I do. I am a postdoctoral researcher, which for the non-academics is a transition between being a student and being in a permanent job (faculty, research etc...). I study volcanic rocks to reconstruct how they got where they are. One way that I do this is through experiments. Experimental volcanology comes in many flavors. Some scientists use things like Karo syrup and honey to mimic lava flows, or glass beads to imitate turbulent flows of rock like pyroclastic flows or mud flows. I happen to be partial to the experiments we do at the University of Buffalo as they use dynamite. The experiments are conducted at the Center for Geohazards Studies Field Station. Its essentially a piece of land that is prepared to be blown up, buried, and generally made a mess of in the name of science.
I am studying volcanic explosions that are produced when magma interacts with water. These explosions are very fast and occur underground, excavating a crater instead of building a classic cone. These volcanoes, called maar-diatremes, are the second most common volcanic landform on land, but we have very few observations of them forming. As a result we are using experiments to study the way these explosions form craters and their underground structures. By taking the experiments out of the lab and up to a size that uses dynamite we can use materials that are complicated and more similar to what would be involved in maar type eruptions.
A maar crater in Michoacan Mexico. Maars are cut down into the crust instead of building upwards. Most of the deposits of a maar volcano are underground. 

What you expect when I say volcano. Cotopaxi Ecuador. Not what I'm talking about here.

Experiments let us design the conditions where the 'eruption' will occur and the ManMadeMaar erupts when we tell it to. (In fact pushing the button is one of the biggest perks of this job!) We also get to dig up our maar and look at the whole structure in three dimensions. Because the explosion that form maars occur underground most of the interesting deposits are underground in a structure called a diatreme. In nature we get to see these rocks in old eroded maar-diatremes, but since this takes hundreds of thousands of years to millions of years we don't get to see the maar and the diatreme of the same volcano. But with our experiments we can speed up time using an excavator and get to the heart of the deposit with just a bit of manual labor.
A maar-diatreme has most of its rocks underground. To see them in nature takes millennia of erosion, which means the maar crater at the surface is gone.

We've been conducting these experiments since 2012 (I joined the group in 2013). So far we have published a slew of papers about the experiments and what they tell us about full sized volcanoes, but there is still heaps more to learn! We are conducting another round of experiments this summer and I hope to share some neat tidbits about the planning process and the motivation for the project. If you want to see some videos of the experiments you can look at the Center for Geohazards Studies Vimeo page.
Craters produced in Man Made Maar Project. We've had over 50 explosions in the name of science since 2012!

You can also find updates about the Man Made Maar blast experiments on twitter with the hashtag #manmademaar and check back on this blog!


Alison Graettinger @AlisonGraetting
http://agraettinger.weebly.com/

  










         

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