ARI SHAPIRO, HOST:
Every day, like clockwork, geysers in Yellowstone National Park erupt in a burst of volcanic activity as tourists ooh and ah at the spectacle.
(SOUNDBITE OF ARCHIVED RECORDING)
UNIDENTIFIED CROWD: (Oohing).
SHAPIRO: That's from a video of Old Faithful, one of some 500 geysers in Yellowstone. New research published in the journal Nature sheds light on what's going on under the surface. Brandon Schmandt of Rice University is one of the authors of the paper and he's here to answer all our burning questions. Thank you for joining us.
BRANDON SCHMANDT: Hi. Thanks for having me.
SHAPIRO: What did scientists already know about the volcanic activity under Yellowstone, and what were you hoping to learn?
SCHMANDT: Well, I think what scientists know and what most people know standing there is that there's got to be a lot of heat in the subsurface. And we could naturally ask, how deep is it? How deep is that beneath me if I'm standing in Yellowstone National Park? And there was a lot of debate about that, with miles of potential uncertainty.
SHAPIRO: Miles of potential uncertainty. So how do you measure something so hot that it could literally melt any measuring device that you might put down there?
SCHMANDT: Yeah, that's a good point. So we don't get to dip a thermometer down into the magma reservoir, though we'd like that. We use a technique called reflection seismology. And so it means we send a seismic wave down and we wait for it to reflect off something and we hear it come back.
SHAPIRO: So you made your own little earthquakes, to quote a Tori Amos album title?
SCHMANDT: Yep. We made our own earthquakes with a large hydraulic truck, all at night on paved roadside turnouts. And thankfully, there are a lot of those to prevent traffic jams so people can watch wildlife in Yellowstone. So we would drive along to these paved roadside turnouts in the middle of the night. And the truck would lift itself up enough to sort of unload the suspension, and then it would vibrate or play this short sequence for about 40 seconds. It would shake on the pavement.
SHAPIRO: Like a jackhammer for 40 seconds?
SCHMANDT: Yeah, except it doesn't lift up and then impact. We're not aiming to break the pavement, and we did not break anything.
SHAPIRO: (Laughter).
SCHMANDT: That's a key point.
SHAPIRO: Glad you didn't break anything in a national park. That's important.
SCHMANDT: Yeah.
SHAPIRO: And when you heard it come back, did you clear up those miles of ambiguity?
SCHMANDT: Exactly. We learned that there is a very abrupt top or cap to that magma reservoir, and that it is about 3.8 kilometers deep.
SHAPIRO: And can you tell whether this is an active volcano that's ready to blow?
SCHMANDT: Yeah, I think we can say something about that, and that it's not. It is not a volcano that's ready to blow, but it is an active volcano. It's still a dynamic system that probably has an interesting future ahead of it, but it is not imminently threatening.
SHAPIRO: Well, beyond just putting a number on how deep the magma goes, what's the use of research like this? What does it help you understand?
SCHMANDT: Sure. Well, the conditions of the magma. If we want to think about whether a magma reservoir is going to be stable or not or what its properties will be, we need to know how deep it is because that controls the pressure. And pressure and temp are just key variables for understanding what magma is doing.
SHAPIRO: You are a scientist at a major university doing research in a national park. Are the federal government's cuts to university research programs and national park funding likely to impact the future of your work?
SCHMANDT: So that's very possible. Through my career, and certainly for this project, it was supported by the National Science Foundation and their geophysics program and coordinated with the National Park Service. And, you know, they have to give us permission, but they have to do quite a bit of work to understand, you know, what we're doing and that it's not going to conflict with all the other public users who love Yellowstone. And so they have to take some time to figure out what we're doing and ensure that it fits within the big picture of how we value our national parks.
SHAPIRO: Brandon Schmandt is a professor of earth sciences at Rice University. Thank you so much.
SCHMANDT: You're welcome.
(SOUNDBITE OF SHABOOZEY AND NOAH CYRUS SONG, "MY FAULT") Transcript provided by NPR, Copyright NPR.
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