Friday, May 15, 2015

Volcano experiments introduction

- Alison

Since I will be talking about experimental volcanology a lot on this blog I wanted to use a post to talk about some of the awesome ways that other research groups are using experiments to study parts of volcanic systems, in particular at the larger scale. You can think of volcanic eruptions as being the result of multiple interacting processes at a range of scales. For example, the growth of crystals in a magma chamber (millimeter to centimeters) influences how the lava will be able to fragment explosively or ooze. At the same time, the shape of the crater or vent (one to hundreds of meters) through which the magma must travel to erupt also controls where material goes and how far (kilometers to hundreds of kilometers). 

Volcanoes and their products don't fit in your average laboratory.
Brave students for scale under a block from block and ash flow in Colorado. 
In order to study how these systems work all together, we must first understand the parts. This is where experiments provide an excellent opportunity to test what we think about the components of an eruption and begin to have a few of them interact in a controlled environment. But this also reveals how important the design of the experiment can be to these studies. Some use analog materials (anything from karo syrup to baby powder) because they are easier to obtain, are cheaper, and have been well studied before. Other studies use natural materials, but the volumes are smaller (lots of experimental petrology uses fist to grape sized samples). However, recent adventures in larger than laboratory experiments mean that we can do more complicated things with natural and analog materials. 

Real lava, but smaller so it fits in the lab (for now). I'll talk about what we are doing in this image in a later blog. 

So what are a few of the exciting trends in experimental volcanology right now?

Lasers! Volcanoes throw a lot of pulverized rock and gas downhill during explosive eruptions. These pyroclastic flows are very difficult to model because of how dangerous they are, and because we cannot visualize what is happening inside them. Ben Andrews at the Smithsonian Institute in Washington DC, USA  is using lasers and flows made of baby powder and other analogs to study how the dilute variety of these flows behave at different temperatures and with obstacles.  

Lots and lots of lava: Syracuse Lava Project is the dream of Bob Wysocki and Jeff Karson to create life sized lava flows out of remelted basaltic lava in Syracuse NY, USA. The group is very good about sharing videos and experiences of their lab online and with local schools. They have used their system to study how lava flows interact with ice, obstacles, and variable slopes. They have also been known to help cook a steak or marshmallows to help inspire curiosity about science and volcanoes. 

Breaking down explosions: The PhysikalischVolkanologisches Labor (PVL) Würzburg, Germany is led by Benrd Zimanowski and Ralf Büttner who have been causing molten fuel coolant interactions (explosions caused by magma and water) for over twenty years.  They also have been recently collaborating with a group in Bari Italy led by Pierfrancesco Dellino to use compressed gas to launch pumice and ash in small plumes to model how natural plumes grow and collapse. 

The University of Munich lab in Germany is always doing something new, its hard to keep up. They do a range of experiments involving fragmentation of magma, how lavas behave, and have even produced volcanic lightning!

Like the bubbles in your beer, bubbles are the key to many volcanic processes. The Durham Lava Analog Volcano Apparatus in the UK is studying how bubbles in melt behave as they travel upwards in a volcanic conduit. They built this apparatus in a quarry to see how scale, or the distances magma travel, influences these bubbly mixtures.

While this list is not complete, it gives some idea of the creativity that is being used to study volcanoes, and the wide range of both questions and techniques that can be used to increase our understanding. Experiments like these, and the ones we do at the University of Buffalo, all work alongside other methods to approach volcanic eruptions. We can take observations from real eruptions to compare with our experimental results, we can look for trends in natural deposits and compare them with what are produced by the experiments, and all of these observations can feed into numerical models that are used to forecast how a lava flow, pyroclastic flow, or explosion may behave in different scenarios. I expect there to be many exciting advances by these labs and others in the near future. I know that my research group has big plans, and I cannot wait to see what experiments will help us discover! 

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