Latest / PlanetGeo: The Geology Podcast / Geysers and Hot Springs: Why They Matter with Examples From Yellowstone National Park

Transcript

Geysers and Hot Springs: Why They Matter with Examples From Yellowstone National Park · PlanetGeo: The Geology Podcast

• 0:03
  SPEAKER_01: Welcome to Planet Geo, the podcast where we talk about our amazing planet, how it works, and why it matters to you.
• 0:13
  SPEAKER_01: So, Chris, this is a this is kind of a crazy well act of Congress that was passed here in 1970, huh?
• 0:21
  SPEAKER_01: That kind of gets us started into this episode.
• 0:23
  SPEAKER_00: It is.
• 0:26
  SPEAKER_00: How did you even manage to come across this act of Congress from something like 1970?
• 0:31
  SPEAKER_01: Well, we were talking about hydrothermal features, and this was on the National Park Service website.
• 0:36
  SPEAKER_01: So what does it say?
• 0:37
  SPEAKER_01: So this is the Geothermal Steam Act of 1970.
• 0:40
  SPEAKER_01: And what a strange name, right?
• 0:42
  SPEAKER_01: I mean, it is.
• 0:43
  SPEAKER_01: Is this a waste of time for Congress?
• 0:44
  SPEAKER_01: I'm not entirely sure.
• 0:45
  SPEAKER_00: I don't know.
• 0:46
  SPEAKER_00: I found it really interesting.
• 0:47
  SPEAKER_00: Basically, the national parks have to keep track of all hydrothermal features in national parks.
• 0:54
  SPEAKER_00: Okay.
• 0:55
  SPEAKER_00: And they have this list, and I went through this, and it's such an extensive list.
• 0:59
  SPEAKER_00: I it was really interesting, actually, but I I couldn't help but laugh at how random it seemed.
• 1:04
  SPEAKER_01: It's you know, it's super random.
• 1:05
  SPEAKER_01: It's super random.
• 1:06
  SPEAKER_01: And so, yeah, 16 national parks have what are quote unquote significant thermal features now.
• 1:13
  SPEAKER_01: I guess to back up, the STEAM Act, this geothermal STEAM Act of 1970, you know, it was passed to encourage the development of geothermal energy and you know governs leasing of geothermal energy resources and all this stuff.
• 1:24
  SPEAKER_01: But, you know, basically it also requires the National Park Service to document all these features, right?
• 1:30
  SPEAKER_01: It's kind of crazy.
• 1:31
  SPEAKER_00: It was.
• 1:31
  SPEAKER_00: It was really random and funny and that, but then also informative because it was holy cow, what an extensive list of hydrothermal features.
• 1:42
  SPEAKER_01: We're kind of getting a little bit carried away.
• 1:43
  SPEAKER_01: So let's let's step back here.
• 1:45
  SPEAKER_01: Let's introduce ourselves real quick.
• 1:47
  SPEAKER_01: Chris, you're Chris Pulheis, uh national award-winning high school teacher from the great state of Michigan, and my former teacher.
• 1:54
  SPEAKER_00: Right on.
• 1:54
  SPEAKER_00: And you are Dr.
• 1:56
  SPEAKER_00: Jesse Rymanck.
• 1:57
  SPEAKER_00: There we go.
• 1:58
  SPEAKER_00: I'm getting sick of saying that, but you're Dr.
• 2:00
  SPEAKER_00: Jesse Rymanck.
• 2:01
  SPEAKER_00: Like you said, one of my former students went on to actually get your PhD in the geosciences, and now a professor at Penn State.
• 2:08
  SPEAKER_01: That's right.
• 2:08
  SPEAKER_01: And this is Plenty of Geo, our podcast where we talk about the geosciences, how cool they are, how important they are, and uh, you know, uh super fun stuff like hydrothermal features, like we're gonna talk about today, Chris.
• 2:20
  SPEAKER_00: Right.
• 2:21
  SPEAKER_00: Today's episode is all about hydrothermal features.
• 2:24
  SPEAKER_00: And hydro means water, and thermal means hot.
• 2:27
  SPEAKER_00: And so we're gonna talk about things like hot springs, geysers, mud pots, or mud volcanoes, and another thing called fumaroles today.
• 2:35
  SPEAKER_01: Yeah.
• 2:35
  SPEAKER_01: And so what we're gonna do here is we're gonna define these features that we're gonna talk about.
• 2:39
  SPEAKER_01: Then we're gonna go into some detail about each one in particular and tell the story that these features tell us about the earth.
• 2:45
  SPEAKER_01: And then we're gonna step back and consider why these things are important to us in a broader societal context and what they can teach us.
• 2:52
  SPEAKER_00: Right.
• 2:52
  SPEAKER_00: So, um, let's go.
• 2:55
  SPEAKER_01: Yeah, let's get into it.
• 2:56
  SPEAKER_01: So let's talk about it.
• 2:57
  SPEAKER_01: But let's we're gonna define some of these things, Chris.
• 3:00
  SPEAKER_01: But first of all, where does this water come from?
• 3:02
  SPEAKER_01: Like we're talking about water and heat, and hydrothermal features are our main way to get heat out of the earth, and water is like the vector for that heat.
• 3:10
  SPEAKER_01: It's bringing heat to the surface.
• 3:11
  SPEAKER_01: But where's the water coming from?
• 3:13
  SPEAKER_01: Like, what are we dealing with?
• 3:14
  SPEAKER_00: Well, you know, that's kind of it it that's kind of complicated because in each place has its own geology, right?
• 3:21
  SPEAKER_00: But generally speaking, you have two sources of water.
• 3:24
  SPEAKER_00: You have this deeper source of water that is very salty, it's a like a hot brine that is heated by a local heat source, okay, like tectonically related, hot spot related, whatever.
• 3:35
  SPEAKER_00: But the water that we see at the surface is fresh water that comes from, you know, rain, snow melt, things like this that's going on at the surface that is sitting on top of this denser, hot, salty brine water solution.
• 3:50
  SPEAKER_00: And so it's getting heated by that, by the water below, actually.
• 3:54
  SPEAKER_00: Okay.
• 3:54
  SPEAKER_01: So we're not dealing with like, you know, a lot of water from a magma or something like that.
• 3:59
  SPEAKER_01: It's mostly either long-lived water that's sitting in rocks down in the crust, or it's rainwater that's percolating down and then coming back up as it gets heated up.
• 4:07
  SPEAKER_01: Okay.
• 4:08
  SPEAKER_01: Yes.
• 4:08
  SPEAKER_01: So let's go through.
• 4:10
  SPEAKER_01: We've got four things here.
• 4:11
  SPEAKER_01: Let's go through and define them.
• 4:12
  SPEAKER_01: They're fumeroles, mud pots, hot springs or pools, and geysers.
• 4:16
  SPEAKER_01: Those are four categories.
• 4:17
  SPEAKER_01: Let's rip through some definitions real quick, Chris.
• 4:19
  SPEAKER_01: So fumerals, start us off.
• 4:21
  SPEAKER_00: All right.
• 4:22
  SPEAKER_00: Well, I think like the way that you listed it is I think the way that I want to talk about this is you know, that's not a random list that you said.
• 4:29
  SPEAKER_00: The difference between these things is really controlled by the amount of water they have.
• 4:33
  SPEAKER_00: I mean, that's the basic gist of it.
• 4:35
  SPEAKER_00: And so fumerals have the least amount of water of all the features we're going to talk about today, and they often also have the highest temperatures.
• 4:43
  SPEAKER_00: So the water boils away before it reaches the surface, and it often results in this kind of hissing sound coming out of the ground.
• 4:49
  SPEAKER_00: You have a hole that's often lined with, you know, bright yellow sulfur crystals and things like that.
• 4:55
  SPEAKER_00: And it just it's it's just hissing, and that's because the water's boiling away.
• 4:58
  SPEAKER_00: It's like a tea kettle kind of.
• 5:00
  SPEAKER_01: So these are like the steam plumes just coming out of the ground, just a plume of steam venting out, and it looks, you know, very uh uh apocalyptic if you have a bunch of these on the landscape.
• 5:10
  SPEAKER_00: Yeah, they do, they're super cool because like in the early morning hours or or in the evening and so on, when the air cools off, that'll cool the water hissing out of the fumarol.
• 5:20
  SPEAKER_00: And so you get this plume of condensed gas of the steam coming out.
• 5:24
  SPEAKER_00: It makes it look like um sometimes these areas are called like the the playground for the demons of the underworld.
• 5:32
  SPEAKER_00: You know, they just that's a good one.
• 5:34
  SPEAKER_00: That's a good one.
• 5:35
  SPEAKER_00: Uh it does.
• 5:35
  SPEAKER_00: It looks straight out of a movie.
• 5:37
  SPEAKER_01: So the next one, you know, playing on that theme, the the playground of the devil, the playground of the devil's, what is it?
• 5:43
  SPEAKER_01: The playground of the devil's.
• 5:44
  SPEAKER_00: The playground for the demons of the underworld.
• 5:46
  SPEAKER_00: There we go.
• 5:47
  SPEAKER_01: That one uh is mud pots.
• 5:49
  SPEAKER_01: So if we add a little bit more water, a fumarol can become a mud pot.
• 5:53
  SPEAKER_01: And certain organisms use hydrogen sulfide that's present there, and they make sulfuric acid.
• 5:58
  SPEAKER_01: And this stuff, when it's mixed with that little bit of water, can basically destroy the rock around it, create this really clay mud kind of thing.
• 6:06
  SPEAKER_01: And these things are often bubbling.
• 6:08
  SPEAKER_01: So if you hear the deep, like rumbling bubbles, that's a mud pot.
• 6:12
  SPEAKER_01: That's gas, steam coming up through this really thick, viscous mud.
• 6:17
  SPEAKER_01: And so this so mud pots have a little bit more water than fumaroles, and that helps create this really thick, sticky mud thing that that steam is bubbling through.
• 6:25
  SPEAKER_00: Right.
• 6:25
  SPEAKER_00: Then we talk about hot springs or pools.
• 6:28
  SPEAKER_00: This has more water than a mud pot.
• 6:30
  SPEAKER_00: It's simple.
• 6:30
  SPEAKER_00: The water washes away the mud.
• 6:32
  SPEAKER_00: And so what you end up with then is this really clean looking, often deep blue color pool of nearly boiling water, not necessarily boiling.
• 6:44
  SPEAKER_00: Sometimes they do, sometimes they don't.
• 6:46
  SPEAKER_00: You know, in order for it to be called a hot spring, it only has to be, I think the technical definition of it is it only has to be like eight degrees warmer than the ambient air temperature.
• 6:55
  SPEAKER_00: Oh, there's a hot spring.
• 6:56
  SPEAKER_00: Yeah.
• 6:57
  SPEAKER_00: Oh, wow.
• 6:57
  SPEAKER_00: Okay.
• 6:58
  SPEAKER_00: Yeah, they don't have to be super hot.
• 7:00
  SPEAKER_00: You know, they often are, but they don't have to be.
• 7:02
  SPEAKER_01: Hot springs are warm springs, huh?
• 7:04
  SPEAKER_01: Okay.
• 7:04
  SPEAKER_01: Right, right on the uh and then we move on to geysers.
• 7:06
  SPEAKER_01: So geysers, these are like the spectacular, stunning ones, tourist attractions.
• 7:11
  SPEAKER_01: You know what a geyser is.
• 7:12
  SPEAKER_01: These are things that boil off water, it boils up and it erupts out in this big steam eruption.
• 7:18
  SPEAKER_01: Um, and the water needs to be pretty hot, hot enough to boil at depth.
• 7:22
  SPEAKER_01: And you know, there's some particulars of a plumbing system in order to generate a geyser, which we will get into in the next thing.
• 7:27
  SPEAKER_00: Yeah, I mean, the bottom line is that you know, geysers and hot springs, hot springs are super common.
• 7:33
  SPEAKER_00: Geysers are the opposite of that, they're extremely, exceedingly rare.
• 7:38
  SPEAKER_01: Yeah, and because speaking of hot springs being common, I mean, some people have maybe had the the pleasure of visiting these hot springs.
• 7:43
  SPEAKER_01: Chris, you and I, we went to one in Colorado while we were on a little camping collecting trip.
• 7:49
  SPEAKER_01: You remember this thing?
• 7:50
  SPEAKER_01: Where was it?
• 7:50
  SPEAKER_01: This was in the collegiate range somewhere, right?
• 7:52
  SPEAKER_00: It was, it was in, I think, southwest Colorado.
• 7:55
  SPEAKER_00: We were near the collegiate peaks, and I think it was we were near Mount Princeton, which I I'm not sure.
• 8:01
  SPEAKER_00: Um, I think it's a Fort Teener, but I'm not sure it's a big, it's a big mountain.
• 8:06
  SPEAKER_00: But that was the weirdest place.
• 8:08
  SPEAKER_00: We went there because we were dirty.
• 8:10
  SPEAKER_00: I mean, oh man.
• 8:11
  SPEAKER_00: We we'd been collecting.
• 8:12
  SPEAKER_00: We this was not a camping trip, Jesse.
• 8:15
  SPEAKER_00: This was straight up a rock collecting trip.
• 8:18
  SPEAKER_01: We were working hard.
• 8:20
  SPEAKER_01: We were working hard and nerding out pretty uh pretty heavily on over some minerals, some amazonites and stuff like that.
• 8:26
  SPEAKER_01: Anyway, we so we get to this hot spring, you're like, we need a shower, and basically they use the whole plumb, the whole plumbing system is using this hydrothermal feature, this hot, this hot water, right?
• 8:36
  SPEAKER_01: I mean, the showers were this salty kind of hydrogen.
• 8:41
  SPEAKER_00: You didn't really feel clean taking a shower, you know, like because the water stunk, you know, and you didn't really feel clean using the toilet either, because it was hot water in the toilet.
• 8:53
  SPEAKER_01: It was like instant 104 degrees, which you can imagine the smells, right?
• 8:58
  SPEAKER_01: I mean, like the this is it was not the most pleasant experience, but we did go sit in the hot spring afterwards, and that was pretty good.
• 9:05
  SPEAKER_01: That that was nice.
• 9:06
  SPEAKER_00: It was well, it was like a swimming pool, you know.
• 9:08
  SPEAKER_00: Literally, it looked like a pool.
• 9:10
  SPEAKER_00: It's a natural hot spring, but they built this structure around it.
• 9:14
  SPEAKER_00: It's just I don't know, it's just a weird place.
• 9:16
  SPEAKER_00: I had forgotten about that until we started thinking about doing this episode.
• 9:19
  SPEAKER_00: I'm like, wait a second, I remember this.
• 9:21
  SPEAKER_00: Yeah, yeah, we're just a very good.
• 9:22
  SPEAKER_00: I mean, we had fun.
• 9:23
  SPEAKER_01: That it was a great time.
• 9:24
  SPEAKER_01: I mean, you know, hot springs have been used for millennia as like you know, healing properties and all stuff.
• 9:29
  SPEAKER_01: I mean, so the point is, is these hydrothermal features are are really everywhere, they're very prevalent, apart from Kaisers.
• 9:34
  SPEAKER_01: Hot springs are prevalent a lot of places, and and they're really important and really useful.
• 9:39
  SPEAKER_01: And we're gonna get into some details for those.
• 9:41
  SPEAKER_00: Which I think it's important to note too that you know the conditions have to be right in order for you to be able to sit in a hot spring.
• 9:47
  SPEAKER_00: I mean, I would say most hot springs you probably can't just go soak in.
• 9:51
  SPEAKER_00: It's either too hot or it's too acidic or the or too basic, whatever the conditions are gonna be.
• 9:56
  SPEAKER_00: It has to be just right in order for this to be a soakable, sit-in-it, therapeutic hot spring kind of thing.
• 10:03
  SPEAKER_01: Yeah, that's right.
• 10:04
  SPEAKER_01: That's exactly right.
• 10:05
  SPEAKER_01: Yeah.
• 10:06
  SPEAKER_01: All right, so we've kind of gone through these four things fumeroles, mud pots, hot springs, and geysers.
• 10:11
  SPEAKER_01: And we're gonna describe these in a little bit more detail, but we're gonna put this in the context of Yellowstone National Park because we have a lot of experience there.
• 10:18
  SPEAKER_01: Yellowstone's famous for its hydrothermal features.
• 10:20
  SPEAKER_01: And, you know, Chris, you have some beautiful descriptions of the hydrothermal features there in Yellowstone.
• 10:26
  SPEAKER_01: You've been teaching this stuff in Yellowstone for many years, right?
• 10:30
  SPEAKER_01: Going on decades.
• 10:31
  SPEAKER_01: So that's right.
• 10:32
  SPEAKER_01: Let's get into this, let's put this stuff in the context.
• 10:34
  SPEAKER_01: So the hydrothermal features are dependent upon water, and this is really well represented in Yellowstone, right?
• 10:40
  SPEAKER_00: It is, yeah, because you have these these lava flows, these caldera forming eruptions and so on, and these lava flows then would come out onto the caldera floor and ooze, but it was so sticky and so on that that these lava flows often didn't come together.
• 10:53
  SPEAKER_00: And so you you created these like lava plateaus, and in between the lava plateaus, you had these basins, and that's where the geysers and hot springs and all this hydrothermal activity is.
• 11:03
  SPEAKER_01: So you're saying you have high elevation hills and lower elevation valleys, basically.
• 11:08
  SPEAKER_01: Right.
• 11:08
  SPEAKER_01: Okay, yeah.
• 11:09
  SPEAKER_01: And we're talking about the hydrothermal features superimposed on that topography then, right?
• 11:13
  SPEAKER_00: Because so, as you just said, they're controlled by water, right?
• 11:16
  SPEAKER_00: And so the higher part of those lava plateaus, they're further away from the groundwater, and so there's less water there.
• 11:23
  SPEAKER_00: And so you can see what we're talking about and how water is controlling the features you get, because higher up on these, you tend to see fumaroles.
• 11:33
  SPEAKER_00: As you go down a little bit further, closer to the water, that's where you're gonna get mud pots because there's a little bit more water, you're closer to the groundwater, and then as you get into the basin itself, that's where you're gonna get the hot springs and geysers because they have the highest amount of water, and it's so down in the basins, you're closer to the groundwater.
• 11:51
  SPEAKER_01: Man, that is so freaking cool.
• 11:53
  SPEAKER_01: It really is that's just totally cool.
• 11:55
  SPEAKER_01: So you can see this.
• 11:56
  SPEAKER_01: Like, wait, is there a hike or of a vantage point where you can kind of look out and see this change with topography?
• 12:01
  SPEAKER_00: Yeah, two things come to mind.
• 12:03
  SPEAKER_00: Uh, I think of like Norris Geyser Basin, which is where the you know, you have the hottest water in the park at Norris.
• 12:09
  SPEAKER_00: And you think about it too, all of these places in Yellowstone are called basins, the geyser basins, whether it's the Biscuit Geyser Basin or the Norris Geyser Basin, the old faithful basin, because they're these areas that are down low, you know, where they have most the most amount of water.
• 12:24
  SPEAKER_00: But anyway, at Norris, you can see as you walk along the boardwalk up high as you start to descend down into the basin, that's where you you'll hear you can hear it.
• 12:35
  SPEAKER_00: This hissing coming out of the ground out of these holes.
• 12:37
  SPEAKER_00: And those are the funerals.
• 12:38
  SPEAKER_00: Yeah, it really is.
• 12:39
  SPEAKER_00: Further down, you can encounter mud pots and so on, but it uh you don't really have a lot of that at Norris.
• 12:45
  SPEAKER_00: The conditions aren't right, but then down in the basin, that's where the geysers and the hot springs are.
• 12:50
  SPEAKER_01: Okay, fumerals, like you said, they're up high.
• 12:52
  SPEAKER_01: They're really hot though, right?
• 12:53
  SPEAKER_01: They boil off all the water, they they're limited water supply, they're really hot features.
• 12:58
  SPEAKER_01: There's a lot of heat in the system, not a lot of water.
• 13:00
  SPEAKER_01: So it's just basically a steam vent.
• 13:02
  SPEAKER_01: And this is what gives you this really well, all these things give off this uh hydrogen sulfide or sulfuric acid sort of smell, this rotten egg smell.
• 13:10
  SPEAKER_01: It's really prevalent.
• 13:12
  SPEAKER_01: It smacks you in the face when you drive into any of these geyser basins in Yellowstone.
• 13:16
  SPEAKER_01: You know, as you mentioned earlier, it gets really beautiful early on in the morning when this is just steam kind of going into the cool air.
• 13:23
  SPEAKER_01: But the mud pots, these are I I like the mud pots.
• 13:27
  SPEAKER_01: These are kind of they're really these funny features.
• 13:30
  SPEAKER_01: They're gurgling, they're kind of silly, they just look ridiculous.
• 13:33
  SPEAKER_01: Like, what the heck is this thing, right?
• 13:35
  SPEAKER_01: Like it's a weird feature.
• 13:36
  SPEAKER_00: It is.
• 13:37
  SPEAKER_00: They're very cool, and I like how they change.
• 13:40
  SPEAKER_00: You never know what they're gonna look like.
• 13:42
  SPEAKER_01: So, what's going on there?
• 13:43
  SPEAKER_01: Why are they changing?
• 13:44
  SPEAKER_01: Why why are they unpredictable?
• 13:45
  SPEAKER_00: You know, early on in the season, you're coming off from spring, you have a lot of snow melt, you have you know, it's wetter, right?
• 13:51
  SPEAKER_00: And so the mud pots are thinner, they're really soupy.
• 13:54
  SPEAKER_00: But then as the season goes on, you get into summer and late summer, but it's much drier, and so the mud pots can then become really thick and sticky, and they look completely different because they're controlled by water.
• 14:07
  SPEAKER_00: And so actually, mud pots, as the season goes on, they can turn into fumaroles.
• 14:11
  SPEAKER_01: Oh, that's interesting.
• 14:13
  SPEAKER_01: So there's two interesting points there, I think.
• 14:14
  SPEAKER_01: Is one is all of these hydrothermal features are really dependent upon water, and so they can be very ephemeral.
• 14:20
  SPEAKER_01: These things change year to year, season to season, they come, they get bigger, they die away.
• 14:25
  SPEAKER_00: A could you drop in big words ephemeral?
• 14:27
  SPEAKER_01: Yeah, you gotta throw in a couple there.
• 14:29
  SPEAKER_01: You're overeducated.
• 14:32
  SPEAKER_01: Definitely.
• 14:33
  SPEAKER_01: Don't deny that.
• 14:35
  SPEAKER_01: So that's one point is these things are constantly changing, and we'll kind of hit this a little bit later on here, too.
• 14:40
  SPEAKER_01: But the other thing for mud pots specifically is that this shortage of water is really important because it concentrates this acid that's breaking up the rocks that's forming this basically mud or the silt, uh, and really breaking these things down and dissolving them.
• 14:54
  SPEAKER_01: So if there's too much water, that acid is too dilute and it's not really as reactive and it's not going to be doing as much dissolving.
• 15:01
  SPEAKER_01: So, two keys there about mud pots and the the the source of water.
• 15:06
  SPEAKER_00: You know, you have these organisms.
• 15:07
  SPEAKER_00: This is it's crazy, right?
• 15:09
  SPEAKER_00: These, first of all, they can live in these conditions.
• 15:11
  SPEAKER_00: They're they're called extremophiles, and it's just awesome and crazy.
• 15:14
  SPEAKER_00: But they use this hydrogen sulfide to produce sulfuric acid, and it's a very potent concentrated acid and it breaks down the rock.
• 15:24
  SPEAKER_00: But you don't have enough water to wash away the mud, so it just accumulates and accumulates, and it's just uh very cool thing.
• 15:31
  SPEAKER_01: Well, we use concentrated sulfuric acid sometimes in the lab to dissolve rocks, and it's very good at dissolving rocks and very not fun to work with.
• 15:39
  SPEAKER_01: Not fun to go in a mud pot either, I'd imagine.
• 15:42
  SPEAKER_00: No, no, that would be uh death for sure.
• 15:45
  SPEAKER_01: So hot springs, like you you mentioned earlier that these things they don't need to be hot necessarily, they can be warm, but they're kind of this little pool or lake or something like that, right?
• 15:55
  SPEAKER_01: That's full of warm water.
• 15:57
  SPEAKER_01: So my guess is that because they're lower down in the valleys, they're near or at groundwater level or at the water table.
• 16:04
  SPEAKER_01: Is that kind of generally right, Chris?
• 16:06
  SPEAKER_01: Are these things mostly near the water table?
• 16:08
  SPEAKER_01: They're relatively more constant in water supply than the more ephemeral mud pots and uh fumarols.
• 16:15
  SPEAKER_01: Is that that's correct?
• 16:16
  SPEAKER_00: Yeah, these tend to be fairly consistent, if you know how they look and most hot springs don't involve boiling water, and that's an interesting thing, but they all have this this gas that's escaping, and so it gives it the visual appearance that it's boiling.
• 16:31
  SPEAKER_00: It's just simply the bubbles that are coming up tend to be carbon dioxide and hydrogen sulfide and sulfur dioxide, these rotten egg-smelling kind of gases, but uh you know, they they're not necessarily or even often boiling.
• 16:46
  SPEAKER_01: And these are the ones that are really quite beautiful, and we'll talk about this briefly, we'll touch on this, the colors here, but the colors here can be be just stunningly cool.
• 16:56
  SPEAKER_01: Uh in Yellowstone and all the other, I mean, some hot springs are less beautiful than others, but some of these are just stunning.
• 17:02
  SPEAKER_00: Yeah, they can be very, very, very beautiful.
• 17:05
  SPEAKER_00: But you know, the thing with hot springs, the earth these pools at the top, the water has this free circulatory path.
• 17:14
  SPEAKER_00: And that's the thing about a hot spring is that the water's free to come and go at will.
• 17:18
  SPEAKER_00: And that's what really makes it different from geysers.
• 17:21
  SPEAKER_01: Yeah, so uh as a great lead-in.
• 17:24
  SPEAKER_01: So geysers are different because their plumbing system is different, and usually it requires this sort of long and winding system with some kink or obstruction in it, which means it needs to be kind of a pressure seal to it, right?
• 17:40
  SPEAKER_01: Um, because we need this eruption.
• 17:41
  SPEAKER_01: And what is going on with the geyser is the water is boiling off in this eruption and it's just ejecting all this pressurized steam, sometimes extremely high up into the air.
• 17:51
  SPEAKER_01: So there's a lot of pressure in these things.
• 17:53
  SPEAKER_01: And if I remember right, Chris, you have a uh little I remember sitting on a boardwalk.
• 17:59
  SPEAKER_01: I think I remember very vividly sitting on a on the railing of a boardwalk.
• 18:04
  SPEAKER_01: I think it was at steamboat geyser, is that right?
• 18:07
  SPEAKER_01: No, not steamboat.
• 18:08
  SPEAKER_01: What's the geyser in Yellowstone that we were at where you do this lecture?
• 18:11
  SPEAKER_00: Yeah, it was at Achinus in Norris Geyser Basin.
• 18:14
  SPEAKER_00: Yeah.
• 18:15
  SPEAKER_00: Yes.
• 18:15
  SPEAKER_01: Okay.
• 18:15
  SPEAKER_01: All right.
• 18:16
  SPEAKER_01: So what is that?
• 18:16
  SPEAKER_01: I I can't remember what your thing is.
• 18:18
  SPEAKER_01: I remember the visual, but I don't remember your analogy.
• 18:21
  SPEAKER_00: Yeah, it was a perfect place to do it.
• 18:23
  SPEAKER_00: I don't do it there anymore because Achinus is not active anymore.
• 18:27
  SPEAKER_00: Achinus, back when you went a long time ago, was very active and it was fairly predictable.
• 18:32
  SPEAKER_00: And so, you know, they had this big boardwalk viewing area where you could watch the whole process develop.
• 18:39
  SPEAKER_00: So it was a perfect spot for while we were waiting to watch this process unfold.
• 18:44
  SPEAKER_01: Hey, Mr.
• 18:45
  SPEAKER_01: Rambly, what's your analogy?
• 18:47
  SPEAKER_01: Come on.
• 18:47
  SPEAKER_00: All right, all right.
• 18:48
  SPEAKER_00: All right, I'm sorry.
• 18:50
  SPEAKER_00: You're right.
• 18:50
  SPEAKER_01: I have my own rambles too, but you need to be called out for them everyone's a little bit.
• 18:54
  SPEAKER_01: I do.
• 18:54
  SPEAKER_00: I know that was bad.
• 18:55
  SPEAKER_00: I'm sorry.
• 18:56
  SPEAKER_00: I apologize.
• 18:57
  SPEAKER_00: What I do is I have this Arillan Meyer flask.
• 19:00
  SPEAKER_00: Okay.
• 19:00
  SPEAKER_01: Um wait, wait, a what?
• 19:03
  SPEAKER_01: This it's a flask.
• 19:04
  unknown: Okay.
• 19:05
  SPEAKER_01: Like uh flask with whiskey in it.
• 19:07
  SPEAKER_00: It's a flask that no, it's not a flask of whiskey in it.
• 19:09
  SPEAKER_00: It's a it's a flask you use in chemistry class.
• 19:11
  SPEAKER_01: Oh, okay, like the the you know, the the pyramid kind of shaped thing.
• 19:15
  SPEAKER_00: Right, yeah, pyramid-shaped thing.
• 19:16
  SPEAKER_00: Yep, absolutely.
• 19:17
  SPEAKER_00: So I I fill that up with water, just a just bottled water, you know, I fill that up, and uh I I j I I drill um a hole in a rubber stopper.
• 19:27
  SPEAKER_00: And so I put the rubber stopper on top of the flask, and then I jam this really it's called a pipette in chemistry class.
• 19:33
  SPEAKER_00: It's this long, skinny glass tube.
• 19:37
  SPEAKER_00: But at the bottom of it, it has this this kind of really narrow kink in it.
• 19:41
  SPEAKER_00: Okay, and and that's what you kind of have to have for geysers.
• 19:44
  SPEAKER_00: So I just put it on a backpacking stove and let it let it all happen, you know.
• 19:50
  SPEAKER_01: So hold on, I'm having trouble picturing this.
• 19:52
  SPEAKER_01: So you've got a long glass straw in this thing, there's a rubber stopper, the straw is going through the stopper into this flask, and where is the kink in the straw?
• 20:02
  SPEAKER_00: The kink is right at the bottom.
• 20:04
  SPEAKER_00: You know, so you have the flask full of water, the tip of the straw is down just barely into the water.
• 20:12
  SPEAKER_01: Oh, okay.
• 20:13
  SPEAKER_01: So that's sitting just in the water.
• 20:14
  SPEAKER_01: Okay.
• 20:15
  SPEAKER_00: Just in the water.
• 20:15
  SPEAKER_00: And then so as the water heats up, just like most things do, hot things expand, right?
• 20:20
  SPEAKER_00: So as the water heats up, it's not boiling, it'll expand and push water up into this glass straw, you know.
• 20:28
  SPEAKER_00: And this straw is about it's over three feet long.
• 20:31
  SPEAKER_00: Oh, okay.
• 20:32
  SPEAKER_01: It's a big one.
• 20:32
  SPEAKER_01: Okay.
• 20:33
  SPEAKER_00: Yeah, yeah.
• 20:33
  SPEAKER_00: I so I have this like really long glass straw that's filling up with expanding water.
• 20:39
  SPEAKER_00: And then as it gets really close to boiling, then it's not quite boiling yet, it gets close to boiling.
• 20:45
  SPEAKER_00: The water at the top of this glass straw gets pushed out due to expansion.
• 20:51
  SPEAKER_00: And so it just kind of burps a little bit of water out.
• 20:54
  SPEAKER_01: Let me step back up and it is so you the water is expanding and being pushed all the way up this three-foot straw, and it starts burping out the top a little bit, right?
• 21:02
  SPEAKER_01: Just kind of gurgling out the top.
• 21:04
  SPEAKER_01: Okay, all right.
• 21:04
  SPEAKER_01: And then the stove is still gone, the stuff stove is still heating right now.
• 21:07
  SPEAKER_01: Okay.
• 21:08
  SPEAKER_00: Yeah.
• 21:08
  SPEAKER_00: And then so what happens then is you push water out of the top of this glass straw, that causes a drop in the weight of the water in that column.
• 21:19
  SPEAKER_01: Uh-huh.
• 21:20
  SPEAKER_01: Okay, here's the key.
• 21:22
  SPEAKER_00: That causes it to instantly boil.
• 21:24
  SPEAKER_00: And so these bubbles then fly up through the glass straw, pushing water out, it erupts.
• 21:31
  SPEAKER_01: Okay, so the key here is if you're a backpacker, you know this to be true, that water boils at a lower temperature, higher elevation, right?
• 21:39
  SPEAKER_01: There's less pressure, less atmospheric pressure.
• 21:41
  SPEAKER_01: The same is going on in this straw at the bottom of the straw.
• 21:44
  SPEAKER_01: As soon as a little bit of water gets pushed out the top, that drops the pressure such that stuff at the bottom can all of a sudden boil off, and then there's a feedback loop here.
• 21:51
  SPEAKER_01: It just all boils off, flashes to vapor.
• 21:53
  SPEAKER_01: And this happens in volcanic eruptions in with magma, when magma boils off like this as well.
• 22:00
  SPEAKER_01: So that's a really good one.
• 22:01
  SPEAKER_01: I like that, Chris.
• 22:02
  SPEAKER_01: That's a great visual.
• 22:03
  SPEAKER_00: It it really is.
• 22:04
  SPEAKER_00: It works every single time.
• 22:06
  SPEAKER_00: It's just, it's uh to me, it's a perfect analogy of like how geysers work, right?
• 22:11
  SPEAKER_00: With geysers, you don't have a free flow of water to the surface.
• 22:15
  SPEAKER_00: You have this kink or this long, long winding path leading to the surface.
• 22:21
  SPEAKER_00: That's how these things happen.
• 22:23
  SPEAKER_01: And that, I guess, would this must this is really predictable exercise that you do in your for teaching purposes, right?
• 22:29
  SPEAKER_01: Like it boils at relatively the same amount of time, right?
• 22:32
  SPEAKER_01: Which kind of teaches us something interesting about things like old faithful, as the geyser in Yellowstone that's famous for what is it, every half an hour or 45 minutes it erupts.
• 22:40
  SPEAKER_01: Is that right?
• 22:41
  SPEAKER_00: Yeah, I think 75 to 90 minutes is oh, it's a lot longer than that.
• 22:44
  SPEAKER_01: Okay.
• 22:45
  SPEAKER_01: Well, anyways, if you have a constant water supply and a constant heat source, it's really predictable.
• 22:50
  SPEAKER_01: If the plumbing system is staying the same, it's gonna just boil off at the same amount of time.
• 22:54
  SPEAKER_01: It's gonna be really reproducible.
• 22:56
  SPEAKER_01: As long as the inputs are constant, it's going to reproduce itself very over and over, which is a kind of an interesting feature of geysers, I think.
• 23:04
  SPEAKER_00: It is, but most of them don't behave that way, they share water between each other, and so one geyser can kind of siphon water away from another one, and so they're very irregular.
• 23:13
  SPEAKER_00: And Old Faithful doesn't do that, it doesn't share water, it's got its own water system, and so it's right now very regular, right?
• 23:23
  SPEAKER_00: But anything could could change that.
• 23:25
  SPEAKER_00: You know, an earthquake could shift the plumbing network below, and all of a sudden, old faithful is not so faithful anymore.
• 23:32
  SPEAKER_01: Yeah, so there are so many of these geysers in Yellowstone, and I think the statistic is over 50% of all the world's geysers are in Yellowstone National Park.
• 23:42
  SPEAKER_01: And so why is that?
• 23:44
  SPEAKER_01: Like, let's get into explaining why that is.
• 23:46
  SPEAKER_01: It's a really cool feature of how geysers work, I think.
• 23:49
  SPEAKER_00: Right.
• 23:49
  SPEAKER_00: You know, we said earlier that hot springs are super common, geysers are not.
• 23:54
  SPEAKER_00: Well, Yellowstone has a special kind of rock, and the rock is rhyolite, which is this very silica-rich, quartz-rich rock, uh indicative of the kind of volcanism that you get at Yellowstone.
• 24:07
  SPEAKER_00: Well, that's important because rhyolite can dissolve in this hot, salty water, the hydrothermal situation that you have existing in Yellowstone.
• 24:18
  SPEAKER_00: And so what happens then is this long winding plumbing network leading to the surface gets coated with what's called center, which is just rhyolite precipitating on the walls of the plumbing network.
• 24:34
  SPEAKER_01: Yeah, and the other thing about silica is exactly as you said, Chris, it gets precipitated.
• 24:38
  SPEAKER_01: And so silica, when it's dissolved in water, gets precipitated out very easily as well.
• 24:44
  SPEAKER_01: Whereas other things like calcium, magnesium, they don't get precipitated out as easily.
• 24:48
  SPEAKER_01: And so, like, this is why our oceans are salty, is because ions are being carried by the rivers in the groundwater system all the way to the oceans.
• 24:57
  SPEAKER_01: Silica doesn't really do that.
• 24:58
  SPEAKER_01: Silica drops out of solution a lot easier, and so it can be dissolved in really hot water, but it also comes out of really hot water more than other ions.
• 25:06
  SPEAKER_01: So the silica is really important for restricting restricting the flow of water.
• 25:12
  SPEAKER_00: It restricts the it creates this pressure tight system.
• 25:17
  SPEAKER_00: Uh, you know, so you think of this this long glass straw that I described earlier, and what happens is that's the plumbing network.
• 25:25
  SPEAKER_00: That's what it looks like.
• 25:26
  SPEAKER_00: You get this mineral precipitated on the inside of that glass straw.
• 25:31
  SPEAKER_00: As it gets precipitated more and more and more and more, the opening becomes narrower, and that creates this pressure tight, restricted flow.
• 25:41
  SPEAKER_00: You know, we talked about this in our earlier episode when we did just Yellowstone and Old Faithful.
• 25:47
  SPEAKER_00: All that water that comes out of Old Faithful is being jammed through an opening that is has a four-inch diameter at about 45 feet below the surface.
• 25:58
  SPEAKER_01: Wow, that's crazy.
• 25:59
  SPEAKER_01: So it's got a kink, you know, it's that yeah, you know, and it's restricted, it's restricted because there's so much silica.
• 26:05
  SPEAKER_01: So Yellowstone has these rhyolites, as you said, Chris.
• 26:08
  SPEAKER_01: And the reason Yellowstone has rhyolites, let's back up a little bit more.
• 26:11
  SPEAKER_01: The crust is super thick there, and there's magmas coming from the mantle that are being coming up at the base of the crust, and it has this really long crustal package to get through, like 45 kilometers of crust to get through, which means that basically you go from basalt or this this dark colored rock all the way to this light-colored rock because it has to go through a very thick package of continental crust.
• 26:35
  SPEAKER_01: So it's already very distilled by the time it gets there.
• 26:38
  SPEAKER_01: That's why there's a lot of rhyolites in Yellowstone.
• 26:39
  SPEAKER_01: It's different than Hawaii, it's different than Iceland or uh the Aleutian Islands.
• 26:45
  SPEAKER_01: It's it's a different type of system, and there's a lot more silica, a lot more rhyolite there.
• 26:50
  SPEAKER_00: Right.
• 26:50
  SPEAKER_00: You basically need for geysers, you have to have a potent heat source, Yellowstone has that.
• 26:56
  SPEAKER_00: You have to have abundant water, Yellowstone has that, and you have to have this pressure tight system, this airtight plumbing kinked network.
• 27:04
  SPEAKER_00: And rhyolite is the key to that.
• 27:07
  SPEAKER_00: And that's what makes Yellowstone then so rare, is it has all three of those in abundance.
• 27:14
  SPEAKER_01: Yes, that's right.
• 27:15
  SPEAKER_01: There are many other locations that have geysers or that have hydrothermal features.
• 27:20
  SPEAKER_01: Hawaii is one of them.
• 27:21
  SPEAKER_01: There's a lot of hydrothermal features in Hawaii.
• 27:24
  SPEAKER_01: There's not as many geysers because Hawaii is dominated by basalt, this rock type that's low in silica.
• 27:31
  SPEAKER_01: It's erupted in the it's a mantle plume, it's erupted in the middle of an ocean.
• 27:35
  SPEAKER_01: Uh, so it didn't have to go through this continental cross where it picked up all this extra silica.
• 27:39
  SPEAKER_01: So it's a totally different system because it doesn't have the silica.
• 27:44
  SPEAKER_01: It has the water supply, it has the heat source, but it doesn't have all this silica.
• 27:49
  SPEAKER_01: So there's less geysers in Hawaii.
• 27:51
  SPEAKER_00: That's right.
• 27:52
  SPEAKER_00: To to give a crude analogy of kind of how this works, you know when you get sick, you kind of get crud in your chest, you know.
• 27:59
  SPEAKER_00: Think of your esophagus as the plumbing network of a geyser.
• 28:03
  SPEAKER_00: The silica that gets precipitated in the plumbing network is like phlegm in your throat.
• 28:08
  SPEAKER_00: And then we cough or we have this kind of violent reflex that loosens it up and ejects it out, right?
• 28:14
  SPEAKER_00: Sometimes that happens in Yellowstone where you have a geyser that has this restricted flow, this the phlegm in the throat, right?
• 28:22
  SPEAKER_00: And a violent eruption tears it out.
• 28:25
  SPEAKER_01: This is a disgusting analogy.
• 28:27
  SPEAKER_00: But it works.
• 28:28
  SPEAKER_00: I just want to go on the record.
• 28:30
  SPEAKER_00: All right.
• 28:30
  SPEAKER_00: So, anyway, you know, but so a geyser can then become a hot spring very easily.
• 28:38
  SPEAKER_00: If you have this violent eruption that rips this lining out of its throat, now the water has a free path to the surface, and a geyser just became a hot spring.
• 28:46
  SPEAKER_01: You know, Chris, I was thinking about this.
• 28:49
  SPEAKER_01: I think we should have a little competition with our analogies.
• 28:52
  SPEAKER_01: Because, you know, that was a good analogy.
• 28:53
  SPEAKER_01: I uh you started out kind of disgusting, but I liked it in the end.
• 28:56
  SPEAKER_01: So I'll give you a point for that one.
• 28:58
  SPEAKER_01: But I think we should have well, we should have a little running uh analogy competition here.
• 29:01
  SPEAKER_00: I am, you know, Jess, this is not even a close contest.
• 29:04
  SPEAKER_00: Um I gave in the last episode the pegmatites, the analogy of you and and how you relate to pegmatites.
• 29:12
  SPEAKER_00: I'm destroying you in this little competition.
• 29:14
  SPEAKER_01: Maybe we shouldn't have all right.
• 29:15
  SPEAKER_01: Let's have maybe we'll put it to a vote and see who's got better analogy about that.
• 29:19
  SPEAKER_01: That's that's fine.
• 29:19
  SPEAKER_00: I don't know, like your messed up analogy of how back arc basins happen.
• 29:25
  SPEAKER_00: You know, you're you're not even in the bulk.
• 29:27
  SPEAKER_01: Hey, we got some good feat.
• 29:28
  SPEAKER_01: Hey, we got some good feedback on that one.
• 29:29
  SPEAKER_01: Some people liked it.
• 29:30
  SPEAKER_01: Some people, a few at least.
• 29:32
  SPEAKER_01: Yeah, they need help.
• 29:34
  SPEAKER_00: So people need help.
• 29:36
  SPEAKER_01: All right, so before we move on to why hydrothermal features are important and we should kind of pay attention to them and monitoring.
• 29:42
  SPEAKER_01: I just there was one statistic that I found really interesting to kind of come back to this ephemeral nature of hydrothermal features.
• 29:48
  SPEAKER_01: There was this geyser in New Zealand in the Taupo volcanic field.
• 29:52
  SPEAKER_01: What's it pronounced?
• 29:53
  SPEAKER_01: What's it called?
• 29:54
  SPEAKER_01: But why mangu geyser?
• 29:56
  SPEAKER_01: And this thing erupted for like five years from 1900 to 1900.
• 30:00
  SPEAKER_01: I'm pretty sure you just mangled the pronunciation of that, but it's it's very possible that it is.
• 30:05
  SPEAKER_01: Um but it it erupted for about five years in the from like 1900 to 1905, and then it just stopped.
• 30:12
  SPEAKER_01: But this thing erupted 1,500 feet in the air.
• 30:15
  SPEAKER_01: I mean, and it was blowing chunks of rock up into the air.
• 30:19
  SPEAKER_01: I can't imagine that.
• 30:20
  SPEAKER_01: I know, I know.
• 30:21
  SPEAKER_00: I it's it's unbelievable.
• 30:23
  SPEAKER_01: It's kind of crazy, and it made me think, Chris, uh, how hot is that water?
• 30:27
  SPEAKER_01: I don't actually know how hot the water is that's coming out as steam.
• 30:30
  SPEAKER_01: Do you know the temperatures involved with these things?
• 30:32
  SPEAKER_01: Like when it truly boils.
• 30:34
  SPEAKER_00: I really don't.
• 30:34
  SPEAKER_00: Um every place has its own thing going on, right?
• 30:38
  SPEAKER_00: But uh there are places in Yellowstone where at depth like uh a thousand feet, the water's in excess of 400 degrees.
• 30:45
  SPEAKER_00: So well beyond the boiling point of normal water that's not under pressure.
• 30:49
  SPEAKER_01: That's Fahrenheit for that.
• 30:50
  SPEAKER_01: That's we're we're in uh Fahrenheit, not Celsius.
• 30:53
  SPEAKER_01: So boiling is 212 for those of non-U.S.
• 30:56
  SPEAKER_01: listeners up there.
• 30:58
  SPEAKER_00: Well, you know, like I wanna I want to talk about something else that it relates to this discussion, though.
• 31:04
  SPEAKER_00: At the end of the last ice age, Yellowstone Lake was bigger, it had more water in it, and it covered areas that are now land surface.
• 31:13
  SPEAKER_00: And so at the end of the ice age, though, you'd have these ice dams that broke and just suddenly released water downstream.
• 31:21
  SPEAKER_00: You know, so what happened then is you had a lot of what are called hydrothermal explosions.
• 31:26
  SPEAKER_00: And Yellowstone has tons of these.
• 31:28
  SPEAKER_00: There's a place like Indian Pond, which is near Storm Point, a very popular, famous place in Yellowstone.
• 31:35
  SPEAKER_00: Indian Pond was one of these hydrothermal explosions.
• 31:37
  SPEAKER_00: It was just the where this, you know, the weight of the water was acting as a pressure cooker.
• 31:44
  SPEAKER_00: And as soon as the ice dams broke, the water was released, the weight was suddenly gone, and the water below there just flashed into steam.
• 31:54
  SPEAKER_01: Let me back up and make sure I'm visualizing this correctly.
• 31:56
  SPEAKER_01: So you've got a lake, a lake that's sitting there that's really high, and that's a dammed up lake.
• 32:01
  SPEAKER_01: So that's the pressure cooker, and then the dam is released, the lake drains a bit, and then that's the pressure release.
• 32:06
  SPEAKER_01: Is that what you're talking about?
• 32:08
  SPEAKER_00: The weight of the water was released downstream, and so the water below was superheated.
• 32:14
  SPEAKER_00: It was just sitting there, but it had all this water on it, the weight of the water, which kept it from boiling.
• 32:20
  SPEAKER_00: So when the ice dams broke, water's gone, weight's gone, flashes into steam, and it explodes.
• 32:25
  SPEAKER_00: And so you have these dimples all over the place in Yellowstone that are these hydrothermal explosions.
• 32:31
  SPEAKER_01: Wow, that's very cool.
• 32:32
  SPEAKER_00: It is.
• 32:33
  SPEAKER_00: Oh, amazing.
• 32:34
  SPEAKER_00: All right, so Jesse, we've covered, you know, the geology behind how these things happen.
• 32:39
  SPEAKER_00: I hope anyway, we did a good job with that.
• 32:42
  SPEAKER_00: But part of this podcast is why?
• 32:44
  SPEAKER_00: Why should this matter?
• 32:46
  SPEAKER_00: Why is this important?
• 32:47
  unknown: Yeah.
• 32:48
  SPEAKER_00: Why do we need to know about geysers and hot springs and all this?
• 32:51
  SPEAKER_01: It's a great question.
• 32:51
  SPEAKER_01: Why do we spend uh half an hour, 45 minutes rambling about hydrothermal features, right?
• 32:56
  SPEAKER_01: Well, it's kind of best represented with this really funny act of Congress, right?
• 33:01
  SPEAKER_01: The Geothermal Steam Act.
• 33:02
  SPEAKER_01: I was shocked that this thing actually existed, but it goes back to 1970.
• 33:06
  SPEAKER_01: Hydrothermal features are part of the geothermal energy conversation for sure.
• 33:12
  SPEAKER_01: Geothermal energy is a huge and growing deal in our society, and we're gonna keep using it and probably make more use out of geothermal energy, and we're gonna have an upcoming episode about geothermal energy pretty soon.
• 33:24
  SPEAKER_01: But by looking at these hydrothermal features, we can monitor two different things basically.
• 33:30
  SPEAKER_01: We can monitor the energy, the geothermal energy part of it, and we can also monitor the hydro part of it, which is water supply.
• 33:37
  SPEAKER_01: And water is a scarce resource, and so by looking at these features and documenting them and monitoring them, we really gain insight into two key features, heat and water, that we cannot directly see in the earth.
• 33:50
  SPEAKER_01: So we're kind of monitoring them to see into the earth with it.
• 33:53
  SPEAKER_01: You know, there's several big monitoring campaigns out there to look at things like the salinity of the hydrothermal features, the temperature of the water coming off of them.
• 34:03
  SPEAKER_01: They're locations, as you've described really well, Chris, like high elevations, low elevations, groundwater, they're intimately related to the groundwater table.
• 34:10
  SPEAKER_01: They're these really cool things, and they also can be used for energy in a place like Iceland, which has this really famous hot spring.
• 34:20
  SPEAKER_01: It's like that really pale blue.
• 34:22
  SPEAKER_01: I'm sure you've seen a photo of it, Chris.
• 34:23
  SPEAKER_01: I don't know.
• 34:24
  SPEAKER_01: There's like lots, maybe on Instagram or wherever you see photos of this kind of stuff.
• 34:28
  SPEAKER_01: Like uh this really pale blue hot spring that people are sitting in, and right behind that, or in that same area, is a geothermal energy plant, and Iceland gets like 25% of its electricity from geothermal energy.
• 34:41
  SPEAKER_01: So they're intimately related to energy.
• 34:44
  SPEAKER_00: Yeah.
• 34:45
  SPEAKER_00: Not to mention also, Jesse, is that you know how studying these hot springs in Yellowstone led to a much broader understanding of these extremophiles, you know.
• 34:56
  SPEAKER_01: Yeah, extremophiles being organisms that can live in extreme environments.
• 35:00
  SPEAKER_00: Yeah, they thrive in it.
• 35:01
  SPEAKER_00: And studying this one hot spring in Yellowstone, they discovered an enzyme that can be used to duplicate DNA.
• 35:09
  SPEAKER_00: This tackle.
• 35:10
  SPEAKER_00: So I kind of interrupted.
• 35:11
  SPEAKER_01: Like the colors are really dramatic and stunning in Yellowstone.
• 35:14
  SPEAKER_01: I remember your lecture on it, but I don't remember what you said again.
• 35:16
  SPEAKER_01: So what are the colors in its how how does it work?
• 35:20
  SPEAKER_01: How's the color range work?
• 35:21
  SPEAKER_00: You know, in in Yellowstone, you typically have the center of a hot spring, it's this deep, beautiful blue color, and then you get this like regular predictable pattern of colors as you go out into the shallower parts of the pool away from the center, you get these concentric rings of color, and those are super cool.
• 35:42
  SPEAKER_00: And we're just gonna do this in a very simple way because this is a bit of a rabbit hole.
• 35:47
  SPEAKER_00: But bottom line is it comes down to temperature, temperature and pH, but mostly temperature.
• 35:52
  SPEAKER_01: And so meaning the color corresponds to a temperature, roughly.
• 35:57
  SPEAKER_00: Yeah, you're right, right.
• 35:58
  SPEAKER_00: It's exactly and you know, at the center of the hot springs in Yellowstone, the highest temperature is there, it's too high for organisms to thrive there, and the the water's deeper there too.
• 36:09
  SPEAKER_00: So the blue that you get at the center of a hot spring is blue for the same reason the sky is blue.
• 36:16
  SPEAKER_00: Blue light is scattered easier than red light, the longer wavelength.
• 36:21
  SPEAKER_00: And so the shorter the wavelength of light, which is blue, it's scattered more easily, and that's reflected back to our eyes.
• 36:27
  SPEAKER_00: It's scattered to our eyes.
• 36:29
  SPEAKER_00: As you go away from that, though, into shallower and cooler water, the first color that is usually encountered is this bright yellow.
• 36:37
  SPEAKER_00: And uh the water there, if you have this bright yellow, that means the water's about 165 degrees Fahrenheit.
• 36:44
  SPEAKER_00: So you have this like concentration of these organisms that reflect yellow light.
• 36:51
  SPEAKER_01: And they love 165 degree Fahrenheit water.
• 36:54
  SPEAKER_00: That's what they love.
• 36:55
  SPEAKER_00: And then as you go away from the yellow, it quite often turns orange, and that's about 149 degrees, and then it can turn this kind of reddish brown or almost like a burgundy color.
• 37:06
  SPEAKER_00: I mean, that's about 131 degrees.
• 37:08
  SPEAKER_00: And so the colors uh usually indicate temperature because that's the kind of bacteria that that thrives at those temperatures.
• 37:19
  SPEAKER_01: Okay, so as we go from hotter to cooler on the edges, you go from blues to yellows to oranges, and then the red and brown red on the edges.
• 37:28
  SPEAKER_00: Yeah, sometimes sometimes you'll get these like reddish brown or burgundy colors.
• 37:32
  SPEAKER_00: You don't always get that.
• 37:33
  SPEAKER_00: And and like I said, this is really complicated.
• 37:36
  SPEAKER_00: You can get green colors too, and that's due to photosynthesis and chlorophyll, and it's a rabbit hole.
• 37:42
  SPEAKER_00: I guess it comes down to also you never know what you're gonna discover as you're learning about these kinds of things.
• 37:49
  SPEAKER_01: I think just to highlight one last uh thing to kind of summarize, these hydrothermal features are really kind of ephemeral.
• 37:55
  SPEAKER_01: They come and go over geologic timescales and human timescales.
• 37:59
  SPEAKER_01: And sometimes when we tap the geothermal energy that is driving the hydrothermal features, like in the southwest US, Nevada, for instance, there are hydrothermal fields that used to have geysers that no longer do because we've put a geothermal energy plant there that is drawing energy, drawing some of that heat energy out of the earth, and we're using it, we're putting it to human use as opposed to being boiled off as steam in a geyser.
• 38:25
  SPEAKER_01: We're using that same energy to generate electricity.
• 38:28
  SPEAKER_01: So, you know, it kind of represents the trade-offs involved and you know, some of the somewhat philosophical discussions revolving around energy and and geoscience.
• 38:37
  SPEAKER_01: Right.
• 38:38
  SPEAKER_01: That's true, that's true.
• 38:39
  SPEAKER_01: Well, I think that's a a pretty good spot there to end.
• 38:43
  SPEAKER_01: Hydrothermal features, they're so cool.
• 38:45
  SPEAKER_01: And like, talk about rabbit holes.
• 38:47
  SPEAKER_01: This whole episode was just a rabbit hole.
• 38:49
  SPEAKER_01: We're going through.
• 38:49
  SPEAKER_01: I mean, we could spend so long talking about these things, diving into them.
• 38:53
  SPEAKER_01: There's different aspects to to why hydrothermal features are important and why we should care about them and how they work and acts of Congress.
• 39:01
  SPEAKER_01: I mean, right crazy.
• 39:02
  SPEAKER_01: What a crazy topic.
• 39:04
  SPEAKER_01: It was so fun.
• 39:05
  SPEAKER_00: Yeah, it was.
• 39:06
  SPEAKER_00: Uh, I love it.
• 39:06
  SPEAKER_00: It's awesome.
• 39:07
  SPEAKER_00: Like again, the abundance of these hydrothermal features is truly amazing.
• 39:14
  SPEAKER_01: Yeah.
• 39:15
  SPEAKER_00: You know, they're just all over the place.
• 39:16
  SPEAKER_01: They're everywhere.
• 39:16
  SPEAKER_01: I mean, there's hot springs in uh, you know, in Pennsylvania.
• 39:19
  SPEAKER_01: And you just got back from uh from Yellowstone where you probably saw these things and you were teaching this class, right?
• 39:25
  SPEAKER_01: So you just saw all these features right in your memory banks.
• 39:28
  SPEAKER_01: That's awesome.
• 39:28
  SPEAKER_00: I just think, you know, too, and when you when you look at these things and you know uh a little bit about how they work, it just deepens your appreciation of it.
• 39:38
  SPEAKER_00: You know, I know uh I'm not right about a lot of things, but I know I'm right about that.
• 39:43
  SPEAKER_00: Is just knowing how these features work and being able to see it laid out with you know the fumarols and then the mud pots and so on and so on.
• 39:52
  SPEAKER_00: Just like that's so cool, you know.
• 39:54
  SPEAKER_00: And I I I try to avoid old faithful at all costs because there just so many people, and but when you're there, the interesting part about it is listening to the people around you, you know.
• 40:05
  SPEAKER_00: And that I've I've heard people talk about come on, you know, turn the water on already.
• 40:10
  SPEAKER_00: They think that it's controlled by the rangers, and old faithful is well, it's it's do they really like it as much as we do if they don't know anything about it?
• 40:19
  SPEAKER_00: I don't I don't know.
• 40:20
  SPEAKER_00: I don't think so.
• 40:21
  SPEAKER_01: Probably not, probably not.
• 40:22
  SPEAKER_01: But not many people probably like it as much as we do, but that's okay.
• 40:26
  SPEAKER_01: They should as long as they like it enough.
• 40:28
  SPEAKER_01: That's the goal.
• 40:29
  SPEAKER_01: Right on.
• 40:29
  SPEAKER_01: Well, I think that's a great spot to end, and I just want to reiterate that Chris Blois is not right about a lot of things.
• 40:35
  SPEAKER_01: That's that seems like a pretty good takeaway point from this podcast.
• 40:38
  SPEAKER_01: It's true.
• 40:39
  SPEAKER_01: As stated by the one and only Chris Bullhoit.
• 40:43
  SPEAKER_01: All right.
• 40:44
  SPEAKER_01: Oh, good stuff, man.
• 40:46
  SPEAKER_01: All right.
• 40:46
  SPEAKER_01: That's a wrap.
• 40:47
  SPEAKER_01: Till next time.
• 40:48
  SPEAKER_00: Yep.
• 40:48
  SPEAKER_01: See you next week.