In the Company of Volcanoes

A guest post: Hello! We are three of Alison’s students at the University of Missouri – Kansas City. Kadie Bennis is a Master’s student in the Department of Geosciences researching subaqueous volcanism while combining both field observations and experimental techniques to characterize sediment-magma interfaces.

-Alison Since I spend a lot of time thinking about holes in the ground, from the ones I make with dynamite , to volcanic craters, I have to spend some time thinking about other mechanisms, both human and natural, that make similar looking holes in the ground. If I want to say anything about volcanic holes in the ground, such as maar volcanoes , I need to know what makes them unique. If I want to recognize just one type of hole in the ground remotely on Earth, or other planets, I need to know more about holes in the ground in general. Google Earth Image of Hole in the Ground Maar (left) and its neighbor Big Hole (right), these maars are located in Western Oregon. Let's start with the largest holes in the solar system, impact craters. One of the most important processes for changing the surface of a planet, or any planetary body (moons, asteroids, etc.) is meteorite impact. There is a lot of junk flying around in space. This junk (rock, dust, ice) runs into other junk an...

-Alison I am always going on about maar volcanoes. So where are the maar volcanoes? These volcanoes are formed by explosions underground occur because magma interacts with water and form unassuming craters. The craters are cut below the ground surface so their outer slopes are fairly shallow, and they are frequently filled with a lake. When there isn’t a large majestic volcano to climb and take fancy sunset photos in front of, it can be hard to get excited about what looks like a little hole in the ground. A picturesque maar crater in Michoacán Mexico. But remember, they are explosive, it takes a lot of energy to carve a big hole in the ground. I use dynamite to make craters that are only 2 meters in diameter (a tall friend lying on their side). We would need about 10,000 sticks of the dynamite we use to get close to the size of a maar volcano. Our experimental maar volcanoes would need to be a LOT bigger to match nature. I have been recently comparing the shapes...

-Alison  No, really! I’ve walked in the same places that the Apollo astronauts honed their geology skills here on Earth. Actually, many a geologist has trained in locations that were used for Apollo training for the precise reason that they are great places to learn geology. Apollo training locations include a fair number of volcanoes, a few impact craters, and other barren rocky landscapes. The point of training, after all, was to prepare them to describe the rocky and otherworldly surface of the moon, and the moon is covered in lava and lots of big impact craters.  Volcanic moon rock at the Chabot Space Center in Oakland California. Image courtesy of Wikimedia Commons.   I encourage geologists and outdoor enthusiasts alike to check out this list of training locations and see how many places you have been that was used to prepare the Apollo astronauts for the moon. I was pleased to note how many places I have visited. In fact, many of the training lo...