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The Boiling Point - Decoding Long Valley Caldera's Volcanic Future · PlanetGeo: The Geology Podcast

• 0:02
  SPEAKER_00: Welcome to Planet Geo, the podcast where we talk about our amazing planet, how it works, and why it matters to you.
• 0:16
  SPEAKER_01: Um I have twenty-three turkeys in my backyard.
• 0:19
  SPEAKER_01: Oh, wow.
• 0:20
  SPEAKER_01: Twenty-three of them.
• 0:21
  SPEAKER_01: That's pretty three.
• 0:22
  SPEAKER_01: That's that's the largest yeah, flock, or I don't know what you call it.
• 0:26
  SPEAKER_01: Gaggle, whatever.
• 0:27
  SPEAKER_01: Gaggle.
• 0:27
  SPEAKER_01: No, I don't know either.
• 0:29
  SPEAKER_00: A whole bunch.
• 0:29
  SPEAKER_01: I it's the largest bunch that I've ever seen in one.
• 0:32
  SPEAKER_00: Why uh why do they enjoy your yard so much?
• 0:35
  SPEAKER_01: Uh they'd like just like to traverse right on through to the back 40.
• 0:38
  SPEAKER_00: They just kind of strut through.
• 0:39
  SPEAKER_00: They do.
• 0:40
  SPEAKER_00: Make sure that you know that they're the boss of your yard.
• 0:42
  SPEAKER_01: That's they do.
• 0:44
  SPEAKER_01: Yeah.
• 0:44
  SPEAKER_01: They're um they're they're entertaining.
• 0:46
  SPEAKER_01: I love that.
• 0:47
  SPEAKER_01: That's pretty good.
• 0:47
  SPEAKER_00: We we had some we had a whole flock of turkeys, like uh, you know, mom and like eight or nine little ones in the fall.
• 0:53
  SPEAKER_00: And then uh our dog had great fun chase giving chicks to them for a while, and uh, they haven't been back uh recently.
• 1:00
  SPEAKER_00: So he it was the best day of his life.
• 1:03
  SPEAKER_00: He got to sprint after some turkeys.
• 1:04
  SPEAKER_00: He's figured out he can't really catch deer.
• 1:06
  SPEAKER_00: He's figured that one out.
• 1:08
  SPEAKER_00: Bunnies, he'll give a little bit of chase.
• 1:10
  SPEAKER_00: Squirrels, not really.
• 1:11
  SPEAKER_00: He just he's kind of know it, learning his limits, but turkeys, he really thought he could get one of those things.
• 1:16
  SPEAKER_01: He was very excited.
• 1:18
  SPEAKER_01: Yeah, that's funny.
• 1:19
  SPEAKER_01: Um, yeah, one was sitting on my on my railing of my deck.
• 1:23
  SPEAKER_01: Oh, really?
• 1:24
  SPEAKER_01: Wow.
• 1:24
  SPEAKER_01: Just perched up there.
• 1:25
  SPEAKER_01: I've never seen that before.
• 1:26
  SPEAKER_01: And I'm like, you know, I first saw it and I'm like, it's like a those things are just mammoths.
• 1:32
  SPEAKER_01: You know, it's huge.
• 1:33
  SPEAKER_01: And it's like you should not be able to be up there.
• 1:35
  SPEAKER_01: Like, how'd you get up there?
• 1:37
  SPEAKER_01: They just don't they don't look right, you know.
• 1:40
  SPEAKER_00: That's funny.
• 1:41
  SPEAKER_00: Looking at you in the window, he's probably looking at you thinking like you don't look right either, man.
• 1:45
  SPEAKER_00: What do you do?
• 1:46
  SPEAKER_00: What's going on with you in there?
• 1:49
  SPEAKER_00: That's good stuff.
• 1:50
  SPEAKER_00: Well, hey, Chris, speaking of turkeys, uh, Long Valley Caldera.
• 1:54
  SPEAKER_01: Terrible sound.
• 1:54
  SPEAKER_01: Not a good transition.
• 1:55
  SPEAKER_01: That was terrible.
• 1:56
  SPEAKER_01: Terrible turkey.
• 1:57
  SPEAKER_00: How do we go from turkeys to Long Valley Caldera?
• 2:00
  SPEAKER_00: Uh let's see.
• 2:01
  SPEAKER_00: A swarm.
• 2:02
  SPEAKER_00: Talking about a big swarm of stuff.
• 2:05
  SPEAKER_00: We have a big swarm of stuff happening at Long Valley Caldera recently, right?
• 2:10
  SPEAKER_01: Yes, absolutely.
• 2:11
  SPEAKER_01: In fact, hey, give me give me a compliment.
• 2:14
  SPEAKER_01: That was not too bad.
• 2:15
  SPEAKER_01: Well, let's turn to that first image that you have playing there right now.
• 2:19
  SPEAKER_01: And this, I like this.
• 2:20
  SPEAKER_01: You did a really good job with it.
• 2:22
  SPEAKER_01: This the first green line just shows the amount of uplift that's happened in the resurgent dome in the last 30 or 40 years.
• 2:32
  SPEAKER_01: Okay, and we're talking about like 83 centimeters of uplift.
• 2:36
  SPEAKER_01: And so, first of all, Jesse, we should define what a resurgent dome is, and then we'll start talking about what this is.
• 2:44
  SPEAKER_00: Let me let me skip ahead here, Chris, to this image so that you can here we we we showed this in a previous episode, but outlines the resurgent dome in green here.
• 2:52
  SPEAKER_00: It's not the entire caldera, it's a small part of the caldera.
• 2:56
  SPEAKER_00: But what's a resurgent dome broadly when we're talking about calderas?
• 2:58
  SPEAKER_01: The resurgent dome is you know, we you had this caldera form an event, and the caldera collapsed down in two kilometers, which is just shocking.
• 3:07
  SPEAKER_01: You know, this would have been a it's amazing, a really very, very cool thing to witness.
• 3:13
  SPEAKER_01: You know, like as long as you're in a hot air balloon, that'd probably be the best.
• 3:16
  SPEAKER_01: Yeah, not on the ground.
• 3:17
  SPEAKER_01: But if you want to survive the event, but you know, so it collapses down in, and this caldera then has a roof.
• 3:22
  SPEAKER_01: But then you get um fresh injections uh or pressure that causes it to like swell up.
• 3:31
  SPEAKER_01: And one of these areas, it's a resurgent dome because the name is self-explaining.
• 3:37
  SPEAKER_01: It's beginning to grow outward from that roof again, kind of like a like a big blister inside the caldera property.
• 3:45
  SPEAKER_00: That's a good analogy.
• 3:45
  SPEAKER_00: Yeah, that's a good analogy, Chris.
• 3:47
  SPEAKER_00: And it uh uh some of the eruptive units, I think they're called the early rhyolite is one of them that's after the caldera forming eruption, but erupted, you know, the the volcano doesn't just shut off after the the big eruption, it kind of still burps and burr, you know, gurgles and spits stuff out, and that stuff can form in part this resurgent dome.
• 4:06
  SPEAKER_00: That definitely happened, but that happened a long time ago.
• 4:10
  SPEAKER_00: You know, the older the big eruption was 761,000 years ago.
• 4:14
  SPEAKER_00: Within the the next hundred to 150, 175,000 years, there was some resurgence.
• 4:20
  SPEAKER_00: There's a lot of resurgence, actually, most of the resurgence, most of the topography we see today in the resurgent dome was that was that uplift.
• 4:27
  SPEAKER_00: Then it was pretty quiet.
• 4:29
  SPEAKER_00: And now, Chris, back to this chart, we're showing uplift.
• 4:32
  SPEAKER_00: You said 83 centimeters, so this is an old chart that only goes to 2006.
• 4:36
  SPEAKER_00: There has been uplift since then, but really this kind of started kicking off in the late 70s, this new sort of renewed uplift, and we're only talking about 80 centimeters here.
• 4:46
  SPEAKER_00: It's enough to measure and enough to get us a little worried and start thinking about what's going on, but it's not the resurgence like you were referring to, this late stage resurgence that happened a long time ago.
• 4:56
  SPEAKER_00: This is new.
• 4:57
  SPEAKER_00: This is new and something we maybe don't know what's going on.
• 5:00
  SPEAKER_00: And that's kind of what we're going to talk about this episode is what's the cause of resurgence.
• 5:04
  SPEAKER_00: It also correlates with earthquakes.
• 5:06
  SPEAKER_00: The other two diagrams on here are just showing it, it corresponds to the other y-axis, the right-hand y-axis.
• 5:12
  SPEAKER_00: It just shows the cumulative number of earthquakes in the caldera in the yellow line, and in the Sierra Nevadas regionally or locally in the orange line.
• 5:20
  SPEAKER_00: And basically the point is that when these lines go vertical, we have a lot of earthquakes in a short amount of time.
• 5:26
  SPEAKER_00: When they go horizontal, it means we don't have very many earthquakes in a long period of time.
• 5:31
  SPEAKER_00: And so these periods where we have a lot of earthquakes correlate with periods of rapid uplift.
• 5:36
  SPEAKER_00: And I don't know, Chris, just looking at this by eye, the correlation's kind of nice.
• 5:39
  SPEAKER_00: I mean, it overlaps pretty well.
• 5:41
  SPEAKER_01: That's a beautiful correlation, actually.
• 5:43
  SPEAKER_01: Um, that's that's amazing.
• 5:44
  SPEAKER_01: You know, the that this resurgence is definitely has something to do.
• 5:49
  SPEAKER_01: It's related to seismic activity also.
• 5:52
  SPEAKER_01: Now, you know, what's causing what?
• 5:54
  SPEAKER_01: That's kind of what this episode is all about.
• 5:56
  SPEAKER_01: Is this because of magma moving up?
• 5:58
  SPEAKER_01: Uh is something else going on.
• 6:00
  SPEAKER_01: That's what we're really gonna dive into the weeds on with this episode.
• 6:04
  SPEAKER_01: But so Chris, let me yeah, sorry, go ahead.
• 6:07
  SPEAKER_00: Yeah.
• 6:07
  SPEAKER_01: No, I was just gonna say, you know, I I was I recently went to a lecture in downtown Grand Rapids, and um one of the leading volcanologists in Iceland is Dr.
• 6:16
  SPEAKER_01: Thor Thorderson.
• 6:17
  SPEAKER_01: He gave a he gave a talk in Grand Rapids at the community college, and uh he was doing something really similar to this.
• 6:25
  SPEAKER_01: He was looking at past eruptions because he's been super active recently and and correlated it with seismic uh in yeah, yeah, okay, cool, very cool.
• 6:33
  SPEAKER_01: And he was he was looking at like real-time data, and he said he was so confident, he said that by the time I get back, this system will be erupting again.
• 6:42
  SPEAKER_01: And sure enough, it was awesome.
• 6:45
  SPEAKER_01: Yeah, two days later it began another spectacular eruption.
• 6:48
  SPEAKER_01: So this was back in late November, yeah.
• 6:50
  SPEAKER_00: Okay, and similar thing happened in the the Hawaiian that what ended up being quite destructive Hawaiian eruptions several years ago now, where where there's this uplift and your earthquake swarm, and this sent a bunch of warning flags off to the volcanologists and to the local communities.
• 7:04
  SPEAKER_00: But Chris, I'm I want you to lean into old man bullheist right now, and I want you to bring us back to the 1980s.
• 7:09
  SPEAKER_00: And when you know, 1985, let's say, there's a bunch of resurgence in uplift and earthquakes happening in the Long Valley Caldera.
• 7:19
  SPEAKER_00: And between this period between 1980 and 1990, the earthquakes are actually getting shallower.
• 7:23
  SPEAKER_00: So, you know, with earthquakes, we can kind of tell where they're occurring at depth, and they're going from eight to four kilometers window to more like uh six to two kilometers window.
• 7:32
  SPEAKER_00: So they're getting shallower with time in that time period.
• 7:35
  SPEAKER_00: What are we thinking about this uplift earthquake combination here in Long Valley Caldera?
• 7:42
  SPEAKER_01: Yeah, I think the you know the knee-jerk reaction is you know, what causes uplift, and everybody rightfully, I think, starts thinking about magma.
• 7:49
  SPEAKER_01: Is magma pushing its way up?
• 7:51
  SPEAKER_01: Is is magma becoming shallower, which is gonna bulge up the rocks into resurgence?
• 7:56
  SPEAKER_01: Is that what's happening?
• 7:58
  SPEAKER_01: And and you know, there's a there's reason for that.
• 8:01
  SPEAKER_01: I mean, you look at 1980 with Mount St.
• 8:03
  SPEAKER_01: Helens.
• 8:04
  SPEAKER_01: On the north facing slope, there was a I don't know how to do it.
• 8:08
  SPEAKER_01: It's it's not a zit, it's maybe a zit on steroids, it's a boil growing off the you know the northern flank of you know I like that.
• 8:17
  SPEAKER_01: That's good.
• 8:17
  SPEAKER_01: Okay, but this this bulge of rock on the north facing slope of of St.
• 8:22
  SPEAKER_01: Helens was a real concern.
• 8:24
  SPEAKER_01: And then that's ultimately it bulged out to the point where it was beyond the angle of repose, and you know, earthquake jot you know, kind of just like jostled it loose and it slid down, and that was like taking the cap off the champagne bottle.
• 8:39
  SPEAKER_01: I mean, it was uh it erupted out of that, and and and so I think yeah, bulging on the inside of a volcano is cause for concern, and and you start to think about magma rightfully so.
• 8:51
  SPEAKER_01: I mean, it had just happened recently, and and actually, Jesse, we got it wrong with St.
• 8:55
  SPEAKER_01: Helens, you know, and that was a part of the thought here too in the 1980s, the early 80s, because they didn't forecast the direction of Mount St.
• 9:04
  SPEAKER_01: Helens, they didn't forecast the size of the eruption, and that was on everybody's mind then when you start to think of Mammoth Mountain in the 1980s.
• 9:14
  SPEAKER_00: So this is really nice.
• 9:15
  SPEAKER_00: This is I I think that's a beautiful framing.
• 9:17
  SPEAKER_00: So why would this be concerning, right?
• 9:19
  SPEAKER_00: Well, I think it's obvious.
• 9:20
  SPEAKER_00: If Mount St.
• 9:21
  SPEAKER_00: Helens just happened, if we kind of know and we can know, we can look at Iceland, we can look at Hawaii when magma's moving, things are happening, uplift happens, then earthquakes happen, and that can lead to eruption.
• 9:31
  SPEAKER_00: That's not necessarily the case, and it's not the prevailing model now for Long Valley Caldera specifically, because there's some really fundamental differences between the volcanic systems in Iceland, Hawaii, and Long Valley Caldera, and actually Mount St.
• 9:44
  SPEAKER_00: Helens, too, very different than Long Valley Caldera.
• 9:46
  SPEAKER_00: And there's kind of two competing viewpoints on this, and they're really boiled down to is there new magma stuff happening down below?
• 9:53
  SPEAKER_00: Or is it just the last gasps of a dying magma chamber that's doing all of this stuff?
• 9:58
  SPEAKER_00: And we can we can really we're gonna kind of try and simplify those down to two end member arguments.
• 10:02
  SPEAKER_00: The answer's somewhere in the middle, maybe, but we got to kind of talk about what this might be.
• 10:07
  SPEAKER_00: So you talked about moving magma, very obvious one.
• 10:09
  SPEAKER_00: I think that makes intuitive sense.
• 10:10
  SPEAKER_00: Magma moves shallower, causes earthquakes, causes uplift, could be the signs of a potential eruption.
• 10:17
  SPEAKER_00: But not necessarily.
• 10:17
  SPEAKER_01: And then you start to think about like, all right, let's go ahead and test this hypothesis then.
• 10:21
  SPEAKER_01: If this is magma, what do we want to do?
• 10:24
  SPEAKER_01: If we had unlimited resources, what would we want to do?
• 10:27
  SPEAKER_01: Uh I think I'd probably want to go to the top of the resurgent dome and bore a hole.
• 10:34
  SPEAKER_01: Yeah, let's let's see where this magma is.
• 10:36
  SPEAKER_01: Yeah, you know, exactly.
• 10:37
  SPEAKER_01: Let's go.
• 10:38
  SPEAKER_01: And that's exactly what they did.
• 10:39
  SPEAKER_00: Right?
• 10:41
  SPEAKER_00: It was part of, I think, Chris, it was part of a Department of Energy funded thing to because it, you know, there's geothermal power plant in this area.
• 10:47
  SPEAKER_00: So looking for geothermal energy, which is just hot rock down beneath our feet, is one really good goal.
• 10:52
  SPEAKER_00: And then I think it was also a second part of drilling.
• 10:55
  SPEAKER_00: I don't know the full history of this, but I think it was supported by the intercontinental um drilling program or something like that, where we drill into continents.
• 11:03
  SPEAKER_00: You can propose scientific reasons for drilling into continental crust or oceanic crust, depending upon which funding stream.
• 11:09
  SPEAKER_00: I actually had a colleague who proposed to drill a hole into a Kimberlite to get a record of these ancient lake deposits that fall, it kind of these really they're they end up creating really small, stable, deep lakes where Kimberlites used to erupt.
• 11:23
  SPEAKER_00: So if you go to 55 million year earth Kimberlite eruption, you have this beautiful lake record sitting in the bottom of that well.
• 11:28
  SPEAKER_00: So they're going to drill through the sediment and then drill into the Kimberlite, and there's big interdisciplinary reasons to do that.
• 11:34
  SPEAKER_00: There, I don't think they ended up doing it, but it's this type of program.
• 11:38
  SPEAKER_01: Okay.
• 11:39
  SPEAKER_01: Did they have any like relation to the mining of diamonds then?
• 11:43
  SPEAKER_01: This project.
• 11:44
  SPEAKER_00: I mean, maybe there was some part of that.
• 11:45
  SPEAKER_00: I think it was more of like how do Kimberlites form?
• 11:48
  SPEAKER_00: What's the magma of Kimberlites?
• 11:50
  SPEAKER_00: That was kind of the questions they were answering, uh, which the mining company is interested in, but I don't think they were looking for diamonds necessarily.
• 11:56
  SPEAKER_01: So Okay, well, anyway, we digress.
• 11:58
  SPEAKER_01: Let's get back to the topic.
• 12:00
  SPEAKER_00: And and they did this, Chris, at the top of the resurgent dome, which again we've highlighted here, which makes sense.
• 12:04
  SPEAKER_00: There's hydrothermal fields, there's geothermal fields all around the edge of this.
• 12:07
  SPEAKER_00: Let's go in the middle, it's where there's resurgence, let's see what's down there.
• 12:10
  SPEAKER_00: And the result was very interesting and not at all scary.
• 12:15
  SPEAKER_00: It was when you get to three.
• 12:17
  SPEAKER_01: Put that image on there, Jesse.
• 12:18
  SPEAKER_01: Put the go to the next image.
• 12:20
  SPEAKER_00: The image, okay.
• 12:20
  SPEAKER_00: There we go.
• 12:21
  SPEAKER_00: So you drill down three kilometers, is is where they got, and the temperature was only a hundred degrees centigrade, just over a hundred degrees centigrade.
• 12:29
  SPEAKER_00: So you could boil water with it, but not much more than that.
• 12:32
  SPEAKER_01: And that's really, really important.
• 12:34
  SPEAKER_00: First of all, why is it sh why is it surprising, Chris?
• 12:36
  SPEAKER_00: Or or why is it uh reassuring, maybe is the right word?
• 12:39
  SPEAKER_00: I'm not sure.
• 12:40
  SPEAKER_01: Yeah, maybe that's a good way of putting it.
• 12:41
  SPEAKER_01: I don't know.
• 12:42
  SPEAKER_01: Um, well, 103 degrees at that depth at three kilometers, that's just the normal geothermal gradient.
• 12:48
  SPEAKER_01: You know, so if we had magma that was shallow, it's gonna be hotter then at that depth, right?
• 12:57
  SPEAKER_01: Even if the magma chamber is below that, it's so big the radiant heat from that is going to cause all the rocks in the surrounding area to be much hotter than 103 degrees, right?
• 13:09
  SPEAKER_01: Yeah, yeah, yeah.
• 13:10
  SPEAKER_01: Um and so this was I think really important in us taking another look at this.
• 13:16
  SPEAKER_01: Well, okay, what else may be causing this resurgence then if it doesn't appear to be magma moving up closer to the surface?
• 13:28
  SPEAKER_00: I think that's really I just want to to to sort of you know focus in on that point you just made, Chris.
• 13:32
  SPEAKER_00: That when you take magma and you move it up to shallow depths, like this image is showing, magma forms deep, it moves up shallow, that magma's hot and it's bringing heat up.
• 13:41
  SPEAKER_00: You can think of it like this is a way to get heat out of the earth is magma migrating upwards.
• 13:46
  SPEAKER_00: Hot magma, 850, 900 degrees, 1200 degrees magma moves up, it brings all that heat up, and when it stalls, it starts to dump that heat into the crust around it.
• 13:56
  SPEAKER_00: It starts to cool off, and that heat goes into the rocks around it.
• 13:58
  SPEAKER_00: So it kind of heats up the whole area.
• 14:01
  SPEAKER_00: Now, if we go back to this map, there's a geothermal power plant, there's hot creek right next door to this resurgent dome where we drilled into the resurgent dome, and we know it's normal geothermal gradient, like 100 degrees at three kilometers depth, is not that different from Pennsylvania or Michigan.
• 14:15
  SPEAKER_00: It's like it's nothing out of the ordinary.
• 14:18
  SPEAKER_00: Why is that?
• 14:19
  SPEAKER_00: How could that possibly be?
• 14:20
  SPEAKER_00: If there's a magma chamber down there, it's more likely everything's gonna be hot.
• 14:24
  SPEAKER_00: The way you can get kind of hot spots is by using water to circulate stuff through.
• 14:29
  SPEAKER_00: So if you have water going down, cold water going down one side, picks up heat down in the crust and then brings it up another side, another vent.
• 14:37
  SPEAKER_00: You know, it's very localized heating that can happen when you have hydrothermal systems, right?
• 14:41
  SPEAKER_00: Yep, um, whereas a big magma body sitting down there is going to heat up everything around it.
• 14:46
  SPEAKER_00: So that was the first indication that maybe this is not magma, or really one of the early indications that maybe this is not magma, and then there's some geological evidence backing that up.
• 14:55
  SPEAKER_00: So the question then that you're posed uh about to was what else could it possibly be?
• 15:02
  SPEAKER_00: And that's a great question, right?
• 15:04
  SPEAKER_01: What could it possibly be?
• 15:06
  SPEAKER_01: Well, one of the leading ideas.
• 15:08
  SPEAKER_01: Yes, I would say that.
• 15:09
  SPEAKER_00: Yep, that's good.
• 15:10
  SPEAKER_01: Is that this is what's called the second boiling, which automatically begs the question.
• 15:17
  SPEAKER_01: You should, you know, if you don't know anything about this, then you're like, well, all right, what's the first boiling then first?
• 15:22
  SPEAKER_01: Let's go.
• 15:22
  SPEAKER_01: Yeah, yeah.
• 15:23
  SPEAKER_00: So there we go.
• 15:24
  SPEAKER_01: Let's talk about the first boiling.
• 15:26
  SPEAKER_00: Yeah, take it away.
• 15:27
  SPEAKER_00: You you touched on this last episode with your uh with your flask analogy, and you do this every year when you go to Yellowstone.
• 15:32
  SPEAKER_00: You talk about uh geyser eruption, you talk about first boiling effectively.
• 15:36
  SPEAKER_00: This is just applied to magmas now.
• 15:37
  SPEAKER_00: So how's it work?
• 15:38
  SPEAKER_01: Yeah, yeah, right, right.
• 15:39
  SPEAKER_01: I think that's that that's the difference.
• 15:41
  SPEAKER_01: We're talking about now magma, and magma has a lot of volatiles in it, and volatiles are just dissolved gases.
• 15:47
  SPEAKER_01: It's got water, carbon dioxide, H2SSO2, a bunch of other things.
• 15:51
  SPEAKER_01: Those are just collectively referred to as the volatiles that are in magma.
• 15:55
  SPEAKER_01: But they're under pressure, and so they're contained in the magma.
• 15:59
  SPEAKER_01: Now, if that magma moves up closer to the surface, it's going to boil off those volatiles.
• 16:06
  SPEAKER_01: They're gonna escape.
• 16:07
  SPEAKER_01: And it's a it's like opening up a uh you know, a 20-ounce bottle of soda, right?
• 16:12
  SPEAKER_01: You you crack the top, it goes like that, and all of a sudden bubbles appear, right?
• 16:17
  SPEAKER_01: And they were there, they were dis the carbon dioxide was dissolved in the in the pop or in the soda until you release the pressure, and then all of a sudden they escape out and they they essentially boil off, right?
• 16:29
  SPEAKER_01: That's the first boiling.
• 16:32
  SPEAKER_00: That is such an important mechanism for big eruptions or any eruptions, really.
• 16:36
  SPEAKER_00: As soon as you pop that top off, you can visualize it kind of simply.
• 16:40
  SPEAKER_00: Let's say you have a magma chamber.
• 16:41
  SPEAKER_00: Magma chambers are rarely just very simple big round balls in the earth that we talk about.
• 16:46
  SPEAKER_00: They're they're disaggregated.
• 16:48
  SPEAKER_00: You pop the top a little bit at the top level one, that part boils off, all those gases kind of explode up the vent.
• 16:55
  SPEAKER_00: That decreases pressure beneath it as well, which then can also undergo first boiling, and all that gas explodes into the vapor phase, brings up magma, the explosion can kind of become this positive feedback loop, and just the whole magma chamber goes until you reach a point where the the pressure or really the magma runs out of gas so that it can't explosively erupt anymore.
• 17:17
  SPEAKER_00: It can't decompressively blow up anymore.
• 17:20
  SPEAKER_00: So that's first boiling, really important, really basic principle of volcanic eruptions of magmatic rocks in general.
• 17:27
  SPEAKER_00: Second boiling, in this diagram we're showing, we're just showing a geothermal gradient.
• 17:32
  SPEAKER_00: You bring magma up to the surface and you can decompress it, right?
• 17:34
  SPEAKER_00: You with the same water content, we'll touch on this later, the same amount of water in a magma, it can become unstable as you go to lower pressures.
• 17:42
  SPEAKER_00: So you depressurize it and it can suddenly not fit in the magma anymore.
• 17:46
  SPEAKER_00: So, what is second boiling?
• 17:48
  SPEAKER_00: That begs the question.
• 17:49
  SPEAKER_00: I'm gonna go to this image here, Chris.
• 17:50
  SPEAKER_00: We're zooming in on a dying magma chamber here, and this is a really common process that's well known in the pegmatite literature.
• 17:57
  SPEAKER_00: The last pegmatites are are kind of thought of as the last dregs of magma chambers, right?
• 18:02
  SPEAKER_01: Like all the stuff that doesn't fit goes into the you and I are a huge, huge fan of pegmatites, huge fan of pegmatites, yeah, exactly.
• 18:09
  SPEAKER_00: Uh we I mean they grow beautiful minerals, they're beautiful rocks, they're incredible because all the weird stuff doesn't fit in these things.
• 18:16
  SPEAKER_00: All the major minerals in a rock, quartz, feldspar, biotite, amphibol, they don't like all the stuff that ends up in pegmatites.
• 18:23
  SPEAKER_00: So pegmatites are a great resource.
• 18:25
  SPEAKER_00: They also are places where there's a lot of volatiles around because volatiles do not fit in minerals.
• 18:30
  SPEAKER_00: So here we're zooming in on a dying magma chamber, and we're saying, okay, we're down at depth, the minerals are crystallizing, this eruption has happened, this stuff didn't erupt, it's sitting around there, it's cooling off.
• 18:40
  SPEAKER_00: The cooling means crystallizing.
• 18:42
  SPEAKER_00: The crystals are growing, and as the crystals grow, eventually it gets locked in place.
• 18:47
  SPEAKER_00: If you grow enough crystals, 50%, 60%, then the magma can't, the whole chamber can't move.
• 18:52
  SPEAKER_00: It's kind of solidly in place, and it's just gonna sit there until it dies.
• 18:56
  SPEAKER_00: A slow cooling death.
• 18:58
  SPEAKER_00: What happens is if you crystallize 50% of the magma, that magma, 100% of the magma had 100% of the volatiles in it.
• 19:04
  SPEAKER_00: Now none of the volatiles go in minerals.
• 19:06
  SPEAKER_00: The minerals don't like these volatiles.
• 19:08
  SPEAKER_00: And so now you have 50% of the magma that has 100% of the volatiles.
• 19:12
  SPEAKER_00: And if you play that forward, you end up with 90% of the minerals, and only the 10% remaining melt has 100% of the volatiles in it.
• 19:20
  SPEAKER_00: So the concentration has gotten enriched, it's gotten distilled.
• 19:23
  SPEAKER_01: It's super saturated.
• 19:24
  SPEAKER_01: That's right.
• 19:24
  SPEAKER_00: And you can drive exactly, you can drive it to saturation and beyond saturation.
• 19:29
  SPEAKER_00: And, you know, let's just put some numbers on this.
• 19:31
  SPEAKER_00: Way back in 1958, Tuttle and Bowen mapped this out.
• 19:35
  SPEAKER_00: In rhyolite, three to four kilometers deep in the crust, you can fit about four weight percent water in it.
• 19:41
  SPEAKER_00: When you go down deeper, 10 to 12 kilometers, you can fit about 8% water in it.
• 19:45
  SPEAKER_00: Now that initial magma probably did not have 8% water in it.
• 19:48
  SPEAKER_00: It probably had, you know, something like two or three or four.
• 19:51
  SPEAKER_00: But as you crystallize this down, the last remaining bit can go above that 8%.
• 19:56
  SPEAKER_00: When you go above that 8%, that gas has to go somewhere, it's not happy in the magma, and it can undergo this second boiling.
• 20:02
  SPEAKER_00: It doesn't explode, it boils off all the volatiles, and all the volatiles kind of go out together.
• 20:09
  SPEAKER_00: And it won't just go out together, it'll you'll lose.
• 20:11
  SPEAKER_00: If you build up to 9% water, 1% will leave, the other 8% will be happy there.
• 20:17
  SPEAKER_00: Then you crystallize a little bit more and you you bleed off a little bit more.
• 20:21
  SPEAKER_00: It's more like a a pressure release valve, Chris.
• 20:24
  SPEAKER_00: Like you kind of the pressure release valve makes sure you don't have an explosion, it's just little bits of boiling off constantly anytime you get above the saturation.
• 20:33
  SPEAKER_01: That's right.
• 20:33
  SPEAKER_01: And those volatiles then are gonna rise up toward the surface.
• 20:36
  SPEAKER_01: Yes and that that is what can cause resurgence.
• 20:41
  SPEAKER_00: That's right.
• 20:43
  SPEAKER_00: That is the second boiling model for uh for this this uplift.
• 20:47
  SPEAKER_00: Is that no, actually, this isn't magma.
• 20:49
  SPEAKER_00: This isn't something really interesting, exciting, perhaps dramatic happening in the magma chamber.
• 20:54
  SPEAKER_00: This is just the natural outcome of a dying magma chamber.
• 20:57
  SPEAKER_00: All those volatiles eventually have to go somewhere.
• 20:59
  SPEAKER_00: They're coming up into the hydrothermal systems.
• 21:01
  SPEAKER_00: It's magmatic water, water from a magma that was formerly in the magma that interacts with groundwater, it's heating it up, and we're doing hydrothermal stuff to drive this seismicity, drive this uplift.
• 21:13
  SPEAKER_00: It's not about the magma chamber, it's not about more magma coming in, it's not about magma moving up, it's about water moving up or volatile moving up.
• 21:21
  SPEAKER_01: Because, Jesse, like, and I think we need to bring this point in is that if it were magma, then you would need fresh injection of magma to keep the system going.
• 21:34
  SPEAKER_00: That's a good point.
• 21:34
  SPEAKER_00: Let that brings us really nicely.
• 21:36
  SPEAKER_00: Can we move to the next to the the kind of seismic imaging?
• 21:40
  SPEAKER_00: Because as you outlined really nicely, this is one model.
• 21:43
  SPEAKER_00: The second boiling is kind of one.
• 21:45
  SPEAKER_00: Maybe it's the dominant model.
• 21:46
  SPEAKER_00: I wouldn't say it's consensus model, but it is it is a major model.
• 21:50
  SPEAKER_00: There are arguments for melt being in place down below, and they come down to seismology.
• 21:57
  SPEAKER_00: So okay, we Talk about P and S waves in our intro level classes.
• 22:02
  SPEAKER_00: What's the valuable difference?
• 22:04
  SPEAKER_00: Here's just a seismogram, typical seismogram.
• 22:06
  SPEAKER_00: P is primary, it arrives first, S is secondary, it arrives second.
• 22:10
  SPEAKER_00: But what's the difference?
• 22:11
  SPEAKER_00: What's the useful difference between these two waves?
• 22:13
  SPEAKER_01: Yeah, the useful difference is that in our classes, we often will talk about the idealized version of a magma chamber where you have this volcanic system and you have this balloon-shaped chamber below, and it's all just liquid, right?
• 22:27
  SPEAKER_01: Well, that doesn't bear out with seismic data because the P waves, which are the primary waves, are the fastest, they're they're essentially just sound waves.
• 22:36
  SPEAKER_01: They can travel through solids, liquids, and gases.
• 22:38
  SPEAKER_01: But the secondary waves, which are the S waves, they can't.
• 22:42
  SPEAKER_01: These are shearing waves.
• 22:44
  SPEAKER_01: And liquids don't have any shear strength.
• 22:47
  SPEAKER_01: So this is how we know what the liquid outer core is.
• 22:50
  SPEAKER_01: We know you know where it is, we know that it's liquid based upon this kind of shadow zone that you get, the absence of S waves that have to travel through the liquid outer core to get to their end destination.
• 23:02
  SPEAKER_01: But we don't get that with volcanoes.
• 23:05
  SPEAKER_01: You don't get these magma chambers.
• 23:07
  SPEAKER_01: S-waves will travel through that hypothesized chamber of magma down there.
• 23:14
  SPEAKER_01: You know, so it means that means it has to be mostly solid.
• 23:17
  SPEAKER_00: It has to be mostly solid.
• 23:18
  SPEAKER_00: And we visualize this as a magma mush.
• 23:20
  SPEAKER_00: It's mostly solid, interlocking crystals that are grown together with a little bit of melt around them.
• 23:26
  SPEAKER_00: And the debate is not, well, the debate is really how much melt.
• 23:29
  SPEAKER_00: Is there a lot of melt or a very little amount of melt?
• 23:31
  SPEAKER_00: So S-waves, when they travel through that type of material, a magma mush, we generally think that they slow down.
• 23:37
  SPEAKER_00: So they don't get blocked, but they slow down.
• 23:39
  SPEAKER_00: And there's been a couple papers in the last decade that thinking of a Flinders et al.
• 23:43
  SPEAKER_00: 2018 one that showed a 15% on average slowdown rate in a potential magma chamber beneath the Long Valley caldera.
• 23:52
  SPEAKER_00: So the S waves are slowing down by up to 15% in this area, which means that there might be magma in there mixed in with the crystals.
• 24:01
  SPEAKER_00: It might be a magma mush network.
• 24:03
  SPEAKER_00: And well, hold on, can I interrupt you, sir?
• 24:06
  SPEAKER_01: Like because Jesse, in my mind, there has to be magma there yet, because we we have not talked about this younger magmatic system.
• 24:17
  SPEAKER_01: You know, when you think about Long Valley, you have two magmatic systems.
• 24:21
  SPEAKER_01: You have the system that is below the the Long Valley Caldera proper.
• 24:26
  SPEAKER_01: What about though, this north-south chain of volcanic mountains that extends from Mammoth Mountain?
• 24:33
  SPEAKER_01: And it's we're talking about the Mono Inyo Craters volcanic chain.
• 24:37
  SPEAKER_01: Yeah.
• 24:37
  SPEAKER_01: So we're kind of all the way up, it culminates at Mono Lake.
• 24:40
  SPEAKER_00: Yeah, we're kind of catching the tail-south part of it right here in the caldera in this topography.
• 24:45
  SPEAKER_00: You can see this really nicely.
• 24:46
  SPEAKER_00: There's these little round hills that go all the way up north, and this is just a southern tail of it, basically.
• 24:50
  SPEAKER_00: But yeah, you're exactly right, Chris.
• 24:52
  SPEAKER_00: So what's the story with these?
• 24:53
  SPEAKER_00: What's what's going on?
• 24:54
  SPEAKER_01: I mean, that's really kind of a cool story.
• 24:56
  SPEAKER_01: Um, you know, you've in the last 50,000 years, you've had you know all kinds of eruptions from the they're smaller scale, but they're they're still kind of impressive.
• 25:07
  SPEAKER_01: In fact, you know, and like I said, uh, have you ever been up to Mono Lake, Jesse?
• 25:11
  SPEAKER_01: No, not to Mono Lake.
• 25:12
  SPEAKER_01: We haven't talked about that.
• 25:12
  SPEAKER_01: Okay.
• 25:13
  SPEAKER_01: You know, Jesse, in the last, well, 50,000 years is when this all began.
• 25:17
  SPEAKER_01: And it it's the last time an eruption happened from this volcanic chain was 250 years ago, which is this island called Payoja in the middle of Mona Lake, 250 years ago.
• 25:29
  SPEAKER_01: So during the last 3,000 years, this chain, there have been eruptions kind of regularly from 750 years, every 750 to 250 years, with the last one being 250 years ago.
• 25:42
  SPEAKER_01: I mean, amazing.
• 25:43
  SPEAKER_00: So clear evidence, right?
• 25:46
  SPEAKER_00: Clear evidence that there is magma down there.
• 25:48
  SPEAKER_00: It's just I think a question of scale.
• 25:49
  SPEAKER_00: Like what is it, is it something big happening in the big magma chamber that could lead to a big eruption, or is it little stuff that's kind of unrelated or maybe little drags and and kind of different, you know, different system altogether, right?
• 26:02
  SPEAKER_01: Yeah, well, they also they think of these as two separate magma that does that it does not like uh there's no magma mixing going on.
• 26:12
  SPEAKER_00: Okay, yeah.
• 26:13
  SPEAKER_00: Well, that's two separate systems.
• 26:15
  SPEAKER_00: It's it's actually quite hard to mix black rock and white rock, black magma and white magma, basalt and rhyolite and get andesite.
• 26:23
  SPEAKER_00: Like they're very different rheologies.
• 26:25
  SPEAKER_00: They it's oil like it, right?
• 26:28
  SPEAKER_00: So yeah, it's it's really hard to get those to to mix, actually.
• 26:31
  SPEAKER_00: So that's just a very that's a topic for another time.
• 26:34
  SPEAKER_00: But um the idea that melt exists in this lower magma chamber could exact, could you're right, be related to the the Monano chain in that what if there's basaltic magma coming up from the mantle, hitting the Long Valley Caldera magma chamber and reactivating that, right?
• 26:52
  SPEAKER_00: And then that's moving up.
• 26:53
  SPEAKER_00: So if we go back to this S-wave velocity reduction thing, it's like kind of 15 on average or you know, maximum, 15% slower, what does that mean for amount of melt?
• 27:03
  SPEAKER_00: We know it's not 100% melt, but it could be up to 23% melt.
• 27:07
  SPEAKER_00: And there's a lot of like give in that model because you have to understand the size of the magma chamber, and you know, you're you're talking about a single wave that goes along a path, and you're detecting a signal along that path, like an integrated signal.
• 27:20
  SPEAKER_00: So it gets a little bit tough.
• 27:22
  SPEAKER_00: But what we know is, Chris, the Long Valley Caldera system, 750,000 years ago, 761,000 years ago, that system could not remain molten for three-quarters of a million years.
• 27:35
  SPEAKER_00: It would have cooled off thermally, it just could not have remained thermodynamics, yeah.
• 27:40
  SPEAKER_00: Yeah, it could it would have cooled off a long time ago.
• 27:42
  SPEAKER_00: So if there's 23% melt down there, then it has to be new melt injection, which could correlate to the eruption time, you know, 90,000 years, 80,000 years eruption time of the volcanic chain, uh, you know, headed north.
• 27:55
  SPEAKER_00: So this is kind of one idea that uh maybe there's some interesting stuff going on with the S waves here, and we can play games comparing the P wave velocities to the S wave velocities and tell something about the system.
• 28:06
  SPEAKER_01: Yeah, but I don't I don't think either one of these ideas are exclusive of the other, right?
• 28:11
  SPEAKER_00: No, I I think that's right.
• 28:12
  SPEAKER_00: I think there could be multiple processes going on, it's probably you know, we've kind of painting them as end member scenarios a little bit, focusing on the uplift, like what's causing the uplift.
• 28:21
  SPEAKER_00: The most recent thing.
• 28:23
  SPEAKER_01: Yeah, that leads us to this this kind of culminating thing, which is a really cool research that I uh I have almost zero experience with this or or knowledge of this, actually, but it's so exciting.
• 28:36
  SPEAKER_01: This fiber optics thing.
• 28:38
  SPEAKER_00: This is well, I have a slightly a little bit more than zero experience with it, but there's there's like graduate students in our department do this.
• 28:44
  SPEAKER_00: I'm not a geophysicist, I'm just always consistently blown away by the techniques that they have at their disposal, like you know, talking to Diana Roman is so exciting because they just have so many cool tools to play with.
• 28:56
  SPEAKER_00: This is a new one, a very cool one, distributed acoustic sensing.
• 28:59
  SPEAKER_00: This has been done as as early or as recently as 2023, a Bondi uh 2023 Science Advances paper that talks about this.
• 29:08
  SPEAKER_00: It's super interesting.
• 29:09
  SPEAKER_00: Basically, what happens?
• 29:11
  SPEAKER_00: Can I run through this just briefly, Chris?
• 29:13
  SPEAKER_00: What's what kind of thing is going on?
• 29:14
  SPEAKER_01: Yeah, well, I'm gonna keep a tight leash on you.
• 29:16
  SPEAKER_01: So let's fair enough.
• 29:17
  SPEAKER_00: We'll keep it tight.
• 29:18
  SPEAKER_00: What's the takeaway with DAS?
• 29:20
  SPEAKER_00: The takeaway with DAS is we're using fiber optic cables as a seismometer, as a bunch of seismometers, basically.
• 29:26
  SPEAKER_00: So you you have a fiber optic cable that's running through the ground or on top of the ground, and you pass a laser pulse, goes down it, and the physics of the fiber optic material are such that if it's strained, that light will get scattered, what's called Rayleigh backscatter, and the light gets scattered, and some of that scattered light heads back towards your what's called an interrogator, the thing that sent out a laser pulse, you detect it back.
• 29:50
  SPEAKER_00: You can calculate how far away that strain is, and so you can actually watch that strain move along the fiber optic cable.
• 29:58
  SPEAKER_00: So just to put some numbers on this, this study I referred to in 2023, they collected for 12 months on a single hundred kilometer long fiber optic cable.
• 30:06
  SPEAKER_00: They got six thousand hundred kilometer long, hundred-kilometer long cable that they're collecting data along.
• 30:12
  SPEAKER_00: And you kind of imagine that's like a bunch of seismometers, basically.
• 30:16
  SPEAKER_00: The fiber optic cables behaving like seismometers.
• 30:19
  SPEAKER_00: For 12 months, they detected 6,000 local and regional earthquakes.
• 30:22
  SPEAKER_00: Of those earthquakes, they didn't just detect 6,000 PNS wave arrival times, they detected 12 million PNS wave arrival times because for each earthquake they get the strain as it's kind of moving along, right?
• 30:34
  SPEAKER_00: It's just amazing.
• 30:36
  SPEAKER_01: So, Jesse, that is really, really important because in geophysics through traditional methods, you the problem is getting data points, getting enough data, right?
• 30:47
  SPEAKER_00: Enough coverage.
• 30:48
  SPEAKER_00: It's it's I think Diana Roman calls it you know um converging ray paths.
• 30:52
  SPEAKER_00: So if you have an earthquake here and a seismometer there, you're only going to detect one wave from that earthquake that hits that particular seismometer.
• 30:59
  SPEAKER_00: I mean, you get more than that, but you're gonna go get one P wave and one S wave.
• 31:03
  SPEAKER_00: So you want as many seismometers and as many earthquakes as possible.
• 31:06
  SPEAKER_00: And so this technique kind of allows you to synthetically have a bunch of seismometers out there that collect different ray paths, different P and S waves as they're hitting, different, they're traversing different parts of the crust.
• 31:17
  SPEAKER_00: So you get more coverage, more density, more and more detailed view of what's in the subsurface.
• 31:24
  SPEAKER_01: Man, my mind goes right away to is this gonna lead to earthquake predictive science?
• 31:33
  SPEAKER_01: This kind of technology that we're talking about here.
• 31:35
  SPEAKER_00: Yeah, I think that a lot of people working on that um from various aspects for sure.
• 31:39
  SPEAKER_00: And I uh it's just an amaz it's a totally this is one of those techniques you kind of I don't know the details here, but I look at it and I'm sort of like, wow, that seems like there's very few downsides.
• 31:49
  SPEAKER_00: Like this this just seems better.
• 31:52
  SPEAKER_01: Okay, hold on.
• 31:53
  SPEAKER_01: So the takeaway, Jesse, is that what they found, what they think on this is that there is a magma chamber deep down, but it's kind of got this rind around it, like a uh or a maybe you think of it as a lid that has prevented it from migrating upward.
• 32:13
  SPEAKER_01: And so in other words, this is very confirming or parallel to the second boiling hypothesis.
• 32:23
  SPEAKER_01: Right, that's right.
• 32:24
  SPEAKER_00: They they would in their their modeling, they've they've suggested that they have imaged the deeper magma chamber and then this rind, and then a gap, and then a little bit of shallow stuff that's likely hydrothermal.
• 32:35
  SPEAKER_00: So I think what their their argument is is that this is actually validating the second boiling hypothesis because we've got this old, we see the old fossil dying magma chamber down below.
• 32:44
  SPEAKER_00: It's got this rind, this thick crystallized rind around it, and that's preventing magma from moving up at all, but hydrothermal fluids can fracture the second boiling process can happen and break through the fractures there, and this water can kind of leak out and get into the hydrothermal system, cause the uplift, cause the earthquakes.
• 33:01
  SPEAKER_00: And there's some interesting seismology of you know, tracking groundwater, like snow melt uh events, and then tracking the seismology.
• 33:09
  SPEAKER_00: And you know, people can look at earthquake, the physics of particular earthquakes, and kind of understand: is this related to groundwater?
• 33:15
  SPEAKER_00: Is this related to magma?
• 33:16
  SPEAKER_00: Is it buildup of strain?
• 33:17
  SPEAKER_00: What's causing the earthquake?
• 33:19
  SPEAKER_00: And so I think it's it's looking like it's much more of a hydrothermal process that's driving the resurgence and the seismicity, a la the second boiling hypothesis, as opposed to you know, a lot of magma moving up and and a worrying amount of magma moving up, maybe.
• 33:35
  SPEAKER_01: So yeah, it's a you know, Jesse, this is an interesting way of I've never heard it called this before, second boiling, but it is a it's a it's a principle that actually happens quite often in geoscience.
• 33:47
  SPEAKER_01: And you like you said, the very important uh pegmatites.
• 33:51
  SPEAKER_01: I've never heard it called that before, but I like it.
• 33:54
  SPEAKER_00: Yeah, it's a good one.
• 33:55
  SPEAKER_00: It's a nice, it's a nice turn of phrase.
• 33:56
  SPEAKER_00: I like it a lot.
• 33:57
  SPEAKER_00: Second boiling.
• 33:58
  SPEAKER_00: And I like I said, this is the the book, it's it's still an open book.
• 34:01
  SPEAKER_00: We're still don't know what's going on.
• 34:03
  SPEAKER_00: I think it's a couple hypotheses.
• 34:05
  SPEAKER_00: Maybe a dominant one is second boiling.
• 34:08
  SPEAKER_00: I wouldn't say it's consensus view, but it's certainly something you will read about Long Valley.
• 34:12
  SPEAKER_00: And there's a discussion.
• 34:13
  SPEAKER_00: And I think this, Chris, this is a fun episode just because we got to showcase the range of tools that volcanologists have at their disposal from geochemical arguments, geological arguments, geophysical things, new cutting-edge geophysical techniques, and first principles petrology, going back to Tuttle and Bowen, 1958.
• 34:30
  SPEAKER_00: It's just a it's just a really rich um scientific discipline that I can understand why people want to become volcanologists.
• 34:37
  SPEAKER_00: Volcanologists are the marine biologists of our world, right?
• 34:40
  SPEAKER_00: Like they are.
• 34:40
  SPEAKER_00: Absolutely.
• 34:41
  SPEAKER_01: It's uh it's our version of swimming with the dolphins.
• 34:43
  SPEAKER_00: Yeah, exactly right.
• 34:44
  SPEAKER_00: It's it's I I get it.
• 34:46
  SPEAKER_00: It's a it's a compelling field.
• 34:47
  SPEAKER_00: You have a lot of tools and fun tools at your disposal.
• 34:50
  SPEAKER_00: So I don't know.
• 34:51
  SPEAKER_00: What do you think?
• 34:52
  SPEAKER_00: Have we done this justice?
• 34:53
  SPEAKER_01: I hope so.
• 34:54
  SPEAKER_01: Uh, you know, this was uh again, uh this turned into a monumental project for us, actually.
• 35:00
  SPEAKER_01: Long Valley Caldera.
• 35:01
  SPEAKER_01: Um it was an idea I had a long time ago, and I'm like, yeah, let's do Long Valley Caldera, and you start diving into this, and the complexity of it is um it's awesome.
• 35:12
  SPEAKER_01: I I had a lot of fun doing this.
• 35:14
  SPEAKER_01: We have one more to go yet, Jesse, because we're gonna interview an expert in this.
• 35:20
  SPEAKER_01: And I can't, yeah, can't wait for that.
• 35:23
  SPEAKER_01: But this was this was fun, and uh, yeah, I think I hope we did it justice.
• 35:27
  SPEAKER_00: I think so too.
• 35:28
  SPEAKER_00: I think so too.
• 35:28
  SPEAKER_01: Just the right amount of weeds.
• 35:30
  SPEAKER_01: I mean, we we went down a lot of rabbit holes, you know.
• 35:32
  SPEAKER_00: Yeah, I know, I know, but it's good to do that.
• 35:34
  SPEAKER_00: And I think we did uh we also got to talk about a lot of fundamentals about volcanoes and and uh fundamental stuff through the lens of the Long Vela Caldera.
• 35:42
  SPEAKER_00: So uh you can find this episode if you're listening to the podcast, find this episode with all the images on our Camp Geo mobile app.
• 35:48
  SPEAKER_00: First link in your show notes, give that a click, or just type Camp Geo into your app store on your mobile device.
• 35:53
  SPEAKER_00: You can find us on all the social medias at Planet GeoCast.
• 35:56
  SPEAKER_00: Send us an email, planetgeocast at gmail.com.
• 35:58
  SPEAKER_00: And uh if you would give us a like, subscribe, and follow on whatever platform you're following us on.
• 36:04
  SPEAKER_00: And give us a rating.
• 36:05
  SPEAKER_00: Five stars would be great.
• 36:06
  SPEAKER_00: Uh let us a rating and leave us a comment if you're on Spotify or YouTube.
• 36:10
  SPEAKER_00: Cheers.
• 36:11
  SPEAKER_00: Peace.