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The Uniqueness of Iceland · PlanetGeo: The Geology Podcast

0:02
SPEAKER_01: Welcome to Planet Geo, the podcast where we talk about our amazing planet, how it works, and why it matters to you.
0:12
SPEAKER_00: One video too.
0:13
SPEAKER_00: Hey, did you know it's Henley season?
0:15
SPEAKER_00: Look at me.
0:15
SPEAKER_00: It is Henley season.
0:16
SPEAKER_00: Did you know that?
0:17
SPEAKER_00: I did know that.
0:18
SPEAKER_00: Yeah.
0:18
SPEAKER_00: It's Henley season.
0:19
SPEAKER_00: You gotta hey, fix your collar though.
0:21
SPEAKER_00: Hey, come on.
0:22
SPEAKER_00: Sorry.
0:23
SPEAKER_01: It's an old one.
0:24
SPEAKER_00: It's an old one.
0:25
SPEAKER_00: It happens with the Henleys.
0:27
SPEAKER_01: So yeah, that's right.
0:30
SPEAKER_01: Chris Balhuis.
0:32
SPEAKER_01: What's up, man?
0:33
SPEAKER_00: Not a whole lot.
0:34
SPEAKER_00: It's uh the weather's getting nice.
0:36
SPEAKER_00: I'm riding my tractor a lot.
0:39
SPEAKER_00: Um, it makes me happy every time.
0:41
SPEAKER_00: I'm just telling you.
0:43
SPEAKER_00: Sometimes I just drive, I go out to the end of my driveway, and I'm like, well, I'm not gonna walk.
0:47
SPEAKER_00: I'm gonna drive my tractor out to the end of the driveway.
0:51
SPEAKER_00: You just got to, man.
0:53
SPEAKER_00: Why not?
0:54
SPEAKER_00: You do.
0:54
SPEAKER_00: I know.
0:55
SPEAKER_00: Yeah, I know.
0:55
SPEAKER_01: I mean, so funny on his tractor.
0:58
SPEAKER_01: I this is just for the listener who's not been to Michigan, you'll drive around.
1:03
SPEAKER_01: If you drive around some of the rural parts of Michigan, you will see the old guys driving their tractor out to get the mail.
1:08
SPEAKER_01: It's the kind of place.
1:11
SPEAKER_01: Chris, well, you're not there yet because you don't look that old, but you're you're not that far off either, Chris.
1:17
SPEAKER_00: I know I'm not so here's the thing.
1:19
SPEAKER_00: If you go out to the end of your driveway with your tractor, the mail goes in the bucket.
1:23
SPEAKER_00: Do you know that?
1:24
SPEAKER_00: Like the goes in the bucket.
1:25
SPEAKER_00: You don't put it on your lap, you don't sit on it, it goes in the bucket.
1:29
SPEAKER_00: And then the tractor's doing work.
1:31
SPEAKER_00: It is a point.
1:33
SPEAKER_01: I have a question for you.
1:35
SPEAKER_01: How you have a long driveway.
1:36
SPEAKER_01: I mean, what is it, a quarter mile, something like that?
1:38
SPEAKER_00: About a quarter mile, yeah, yeah.
1:40
SPEAKER_01: So is that one beer's worth of a drive on your tractor out and back?
1:44
SPEAKER_00: Or well, it has a cup holder.
1:46
SPEAKER_00: So one for the hand and one for the cup holder, Jesse.
1:48
SPEAKER_00: Come on, do you know me?
1:49
SPEAKER_00: One for the trip out and one for the trip back.
1:53
SPEAKER_00: Well, because at the end of my driveway is a dirt road.
1:56
SPEAKER_00: So of course, I have to play in the dirt, right?
1:59
SPEAKER_00: I I have to move some of the gravel around at the end of my driveway.
2:02
SPEAKER_00: Exactly.
2:02
SPEAKER_00: Yeah, yeah, yeah.
2:03
SPEAKER_00: So it's not just out and back.
2:05
SPEAKER_00: I gotta get the mail, I gotta put it in the bucket, but that's after I move dirt at the end of my driveway, just for the sake of moving dirt.
2:12
SPEAKER_01: So fun.
2:12
SPEAKER_01: Crisp Bull Hessan's tractor.
2:14
SPEAKER_01: That just gives me great joy thinking about that.
2:16
SPEAKER_00: Did I tell you though?
2:17
SPEAKER_00: Okay, so we just had the auroras, right?
2:21
SPEAKER_00: The famous event.
2:22
SPEAKER_00: Like this was amazing.
2:23
SPEAKER_00: I took unbelievably there the pictures I have are just spectacular.
2:28
SPEAKER_00: This and we laid in the middle of my driveway.
2:31
SPEAKER_00: I went out at like 10 o'clock at night on that Friday.
2:34
SPEAKER_00: I looked up, I'm like, oh my gosh.
2:36
SPEAKER_00: I ran up but sprinted inside.
2:39
SPEAKER_00: Jenny is like, what is going on?
2:40
SPEAKER_00: I sprinted inside, grabbed sleeping bags, pillows, and I'm like, come on, let's go.
2:44
SPEAKER_00: So we went out into the middle of the driveway.
2:46
SPEAKER_01: Let's go do it.
2:47
SPEAKER_00: Laid down, and we spent like a couple hours out there.
2:49
SPEAKER_00: Anyway, the next night was another possibility, a Saturday night.
2:52
SPEAKER_00: So I went out there again with Jenny.
2:55
SPEAKER_00: We got everything, bathrobes on, sleeping bags on.
2:58
SPEAKER_00: That's a really good mental image for you, right?
3:00
SPEAKER_01: Two old people wearing bathrobes, bathrooms and sleeping, shuffling out, doing the penguin walk in the sleeping bags.
3:07
SPEAKER_01: Oh, yeah.
3:08
SPEAKER_00: Did I tell you what happened?
3:09
SPEAKER_00: I laid there for like an hour.
3:10
SPEAKER_00: Just it was beautiful.
3:12
SPEAKER_00: It was clear, but there wasn't anything really spectacular to see, especially when you compare it to the night before.
3:17
SPEAKER_00: Anyway, then I don't know what happened.
3:20
SPEAKER_00: I woke up at like 1 30 in the morning.
3:22
SPEAKER_00: I fell asleep in my driveway.
3:24
SPEAKER_00: I'm just, I am out.
3:26
SPEAKER_00: Jenny's gone, and I'm like, I look over to I'm like, oh, I guess I'm all alone.
3:31
SPEAKER_00: What time is it?
3:31
SPEAKER_00: Oh my gosh, it's 1 30.
3:33
SPEAKER_00: I've been out here for like three hours.
3:35
SPEAKER_00: So I just then got up and went inside and went to bed.
3:38
SPEAKER_00: So there's my story, but I fell asleep in my driveway.
3:41
SPEAKER_01: I mean, that's pretty good though.
3:42
SPEAKER_01: I uh, you know, no better reason to fall asleep than trying to catch some beautiful northern lights, right?
3:46
SPEAKER_01: That's right.
3:47
SPEAKER_00: Yep.
3:47
SPEAKER_01: It's better than any other excuse you could have for falling asleep in your driveway, I think.
3:51
SPEAKER_01: So otherwise, yeah.
3:53
SPEAKER_01: That's a good one.
3:53
SPEAKER_01: Otherwise, it's just weird.
3:54
SPEAKER_01: But if you're you know, trying to catch some northern lights.
3:56
SPEAKER_01: It's still a little weird.
3:57
SPEAKER_00: Like I yeah, I I told my students about it and I got some funny looks, like, Mr.
4:02
SPEAKER_00: Boyce, like what are you doing?
4:04
SPEAKER_00: You are such a nerd, dude.
4:05
SPEAKER_00: You are such a nerd.
4:06
SPEAKER_00: I know, but I embrace my nerdness and I'm totally I'm good with it.
4:10
SPEAKER_01: So speaking of Northern Lights, maybe this isn't a great segue.
4:14
SPEAKER_01: Not trying to win the Segway Award with this one, but this episode, Chris, is okay, this is gonna be an introduction a little bit.
4:21
SPEAKER_01: The topic is Iceland, which is a very, very deep topic, and you are probably pretty far down in the rabbit hole of planning your trip to Iceland.
4:30
SPEAKER_01: But you're going to Iceland this summer.
4:32
SPEAKER_01: You'll leave after this episode releases, probably, but you're in the midst of planning it right now.
4:36
SPEAKER_01: And to be honest, I'm pretty jealous of this.
4:39
SPEAKER_01: And I think there's a lot of geologists out there who are jealous, if they've not been to Iceland, are jealous of you going to Iceland because it's just one of those top couple, top five geotourist places to go to.
4:53
SPEAKER_01: Iceland is, I think.
4:54
SPEAKER_01: I mean, is that is that accurate?
4:55
SPEAKER_01: Would you think that too?
4:56
SPEAKER_01: Like most geologists probably want to go to Iceland.
4:58
SPEAKER_00: I think so.
4:58
SPEAKER_00: If you're a geologist and Iceland is not on your list, then there's something the matter with you.
5:03
SPEAKER_00: Um, I I don't know.
5:06
SPEAKER_00: Like, what is going on?
5:09
SPEAKER_00: But yeah, I always wanted to go to Hawaii.
5:11
SPEAKER_00: That was always our thing.
5:12
SPEAKER_00: So, Jenny, my beautiful wife and I, we're having our 30-year anniversary this summer.
5:17
SPEAKER_00: So we'll be out in Iceland on our congratulations, congratulations, thank you.
5:21
SPEAKER_00: Yeah, yeah, yeah.
5:22
SPEAKER_00: Yeah, you know Jenny, so it's difficult.
5:24
SPEAKER_00: And and so congratulations to Chris.
5:27
SPEAKER_01: You get the survivor award.
5:29
SPEAKER_01: No, I'm kidding, Jenny.
5:30
SPEAKER_01: I'm kidding.
5:31
SPEAKER_01: I'm kidding.
5:32
SPEAKER_01: You Jenny, Jenny gets the award.
5:33
SPEAKER_00: Jenny does get the award.
5:35
SPEAKER_00: But anyway, we always thought we would go to Hawaii.
5:38
SPEAKER_00: And Jesse, when I started digging into Iceland, I don't know.
5:42
SPEAKER_00: Like, why did I not have this as my number one destination?
5:46
SPEAKER_00: And it was Hawaii.
5:48
SPEAKER_00: Like, the more I dig into this, I can't tell you how excited I am.
5:52
SPEAKER_00: I have a hard time sleeping sometimes because I start thinking about this.
5:55
SPEAKER_01: I totally get that.
5:56
SPEAKER_01: And I think um we've talked about this briefly before, but I'm particularly jealous amongst the geologists because Iceland's a really interesting place.
6:04
SPEAKER_01: Like it is a very, it's cool.
6:06
SPEAKER_01: The landscape is amazing because of the geology.
6:09
SPEAKER_01: But the geology at the depth of Iceland is really, really unique on Earth.
6:13
SPEAKER_01: It's the only place that has this particular geological setting, and it's a really important one, at least in my opinion, for understanding the early Earth.
6:22
SPEAKER_01: It's a proto-continent.
6:23
SPEAKER_01: Iceland is a on the way to being a continent.
6:26
SPEAKER_01: It's born in the ocean, but it's probably not going to be subducted like most oceanic crust.
6:32
SPEAKER_01: It's probably going to end up, it's going to be part of the continents someday.
6:36
SPEAKER_01: And there's some interesting reasons why that is the case.
6:38
SPEAKER_01: But for me, there's like a big scientific draw to Iceland, let alone the landscape and the volcanoes and all this stuff, right?
6:44
SPEAKER_01: So there's kind of two parts to this, right?
6:46
SPEAKER_00: And and I think we'll we're gonna but they're not exclusive, though.
6:49
SPEAKER_00: That's the thing, is that these two parts, to me, to you and I, you can't separate the formation of Iceland and what it means geologically.
6:57
SPEAKER_00: You can't separate it from the unbelievably beautiful scenery.
7:00
SPEAKER_00: Also, those two things are married together, and it's just it makes it so much better.
7:06
SPEAKER_01: So, Chris, let me just propose a way to go through this because I think, like you said, this is gonna be kind of a part one-y episode here, a bit of an overview, and we'll we'll go into more detail because there's a lot of detailed geology in Iceland that's really cool and unique.
7:19
SPEAKER_01: We're gonna stick to the high-level stuff.
7:21
SPEAKER_01: So, what do you say we we kind of go really high-level tectonic setting of Iceland?
7:26
SPEAKER_01: What's unique about it?
7:27
SPEAKER_01: And then we have a part, a sort of a second part of this episode, which is kind of you give us current events on your planning.
7:33
SPEAKER_01: Where are you at in your planning?
7:34
SPEAKER_01: How are you thinking about it?
7:35
SPEAKER_01: How have you started doing your research to go into this?
7:37
SPEAKER_01: And what have you learned so far, maybe?
7:39
SPEAKER_01: And then we can tidy that up later, either before you go or after you go.
7:43
SPEAKER_01: How's that sound?
7:44
SPEAKER_00: It sounds great to me.
7:45
SPEAKER_00: I'm excited to talk about it because I you know, I think about it pretty much all the time.
7:49
SPEAKER_01: So yeah, I mean, it's so cool.
7:51
SPEAKER_01: I have colleagues that go there and we, you know, we've analyzed rocks from Iceland in our lab here at Penn State.
7:56
SPEAKER_01: For me, it's you it's cool because it's a totally unique tectonic setting on Earth.
8:00
SPEAKER_01: It has a mantle plume and a mid-ocean ridge.
8:04
SPEAKER_01: And so those are two areas that exist in other parts of the world where the mantle's upwelling, but Iceland has both of them.
8:11
SPEAKER_01: And for me, Chris, and I I'm curious about your response to this.
8:14
SPEAKER_01: For me, the most interesting surface representation of that is that on Iceland, around about a quarter of the rocks are felsic, which is incredibly high amount compared to any other place in the oceans.
8:27
SPEAKER_01: Any ocean island basalt province, any hotspot volcanism, any mid-ocean ridge, they have a couple percent felsic rocks.
8:35
SPEAKER_01: This has 15 to 25 percent in Iceland.
8:38
SPEAKER_00: And you get this really big diversity then of the personality of the volcanism that that comes out, right?
8:45
SPEAKER_00: And why?
8:46
SPEAKER_01: Why can you explain that a little bit?
8:47
SPEAKER_01: Like, and what do you mean by personality?
8:49
SPEAKER_00: Well, that's the way I describe it when I talk about volcanoes, is they have their personalities.
8:54
SPEAKER_00: And we did an episode on or a couple episodes on the nature of volcanoes and the types of volcanoes and how they're all like snowflakes, and and they are you can't they're hard to put in a box and and say, okay, shield volcanoes, and this is how they are.
9:08
SPEAKER_00: But Iceland breaks a lot of the rules in this because, like you said, it is a it's a mid-ocean ridge, and it's the only place in the world that a mid-ocean ridge is comes out of the ocean.
9:19
SPEAKER_00: It's so many layered or layer upon layer upon layer that it actually pops out of the ocean.
9:23
SPEAKER_00: It's the only place in the world where we have this.
9:25
SPEAKER_00: But that kind of volcanism intensity.
9:26
SPEAKER_01: Let me interrupt you.
9:27
SPEAKER_01: You mean that the surface is exposed above sea level.
9:30
SPEAKER_01: Absolutely.
9:31
SPEAKER_01: The rocks are that's what you mean by pops above the surface.
9:33
SPEAKER_01: Yeah, exactly.
9:34
SPEAKER_00: Yes.
9:34
SPEAKER_00: Yeah.
9:35
SPEAKER_00: So that kind of volcanism is mafic.
9:37
SPEAKER_00: You tend to get basaltic rocks, these black, fine-grained, igneous extrusive rocks.
9:42
SPEAKER_00: But personality is tends to be very, for the most part, quiet and gentle eruptions, right?
9:48
SPEAKER_00: These typical classic Hawaiian type eruptions.
9:52
SPEAKER_00: But Iceland, you get everything really.
9:55
SPEAKER_00: You get andesitic eruptions like what you get in the Andes Mountains or the Cascades in the northwest part of the U.S., you know, these kind of episodic, they can be extremely violent eruptions, but they don't happen very frequently.
10:07
SPEAKER_00: And then they you, like you said, you also get these felsic eruptions, which is kind of the nastiest of the nasty, the Yellowstone or the Long Valley caldera kind of very infrequent but cataclysmic eruptions, right?
10:22
SPEAKER_00: And and Iceland has all of that.
10:23
SPEAKER_01: Yeah, let me interrupt because it because a lot of European to eastern US or eastern North American flight paths go right over Iceland.
10:31
SPEAKER_01: And so Iceland's a massive hazard for air travel.
10:35
SPEAKER_01: And I think it was 2019 or 2020 2019 or 2019.
10:39
SPEAKER_01: Well, 2010.
10:40
SPEAKER_01: A big one, but there was a more recent big eruption that disrupted a lot of air travel.
10:45
SPEAKER_01: Um I can't remember what year it is now.
10:47
SPEAKER_01: I should we should have looked this up.
10:48
SPEAKER_01: But anyway, these bigger eruptions, the non-Hawaiian, the more violent personality types, those ones can disrupt air travel because I throw so much ash up into the atmosphere that planes have to, you know, fly around it or or not travel.
11:01
SPEAKER_00: And then the prevailing winds take the ash over to Europe and it, you know, it does create a lot of havoc.
11:06
SPEAKER_00: The personality of these volcanoes is determined by what we call in geology the viscosity of the magma, you know, how sticky it is, how thick it is.
11:15
SPEAKER_00: We can simplify this.
11:16
SPEAKER_00: Everybody can understand this.
11:18
SPEAKER_00: Black rock means it came from mafic magma, and mafic magma tends to be thinner and runnier.
11:25
SPEAKER_00: And the thinner and runnier it is, the quieter the eruptions are going to be.
11:29
SPEAKER_00: It doesn't have to build up a lot of pressure, it doesn't tend to get stuck as it traverses the crust to come up and out.
11:36
SPEAKER_00: And then the stickier it gets, the more violent it gets.
11:40
SPEAKER_00: And that correlates with more felsic kind of magma.
11:44
SPEAKER_00: It's rich in quartzes and feldspars, and it forms light-colored rocks.
11:49
SPEAKER_00: And when I talk about personality, that's what I'm referring to is the viscosity of the magma.
11:55
SPEAKER_01: Let's sort of square those two comments.
11:57
SPEAKER_01: Why is the tectonic setting, which we said is very unique, the coincidence of a mantle plume and a mid-ocean ridge in the same spot?
12:03
SPEAKER_01: Iceland's unique on Earth.
12:05
SPEAKER_01: It's the only place that has that.
12:06
SPEAKER_01: And we have this wide variety of rock types and therefore volcano personalities on Iceland.
12:12
SPEAKER_01: The link between those two is heat.
12:14
SPEAKER_01: There is extra heat because we have a mantle plume and a mid-ocean ridge.
12:19
SPEAKER_01: We have more mantle upwelling, it's hotter mantle, it's more melting, more volcanism, more basaltic volcanism, and more heat in that crustal package.
12:29
SPEAKER_01: So we've just got a thicker crust there, and it's not moving away as quickly.
12:36
SPEAKER_01: It's kind of piling up more, I guess, if that makes sense.
12:39
SPEAKER_01: Which what does it mean when basalt, when you pile up basalt on top of each other?
12:42
SPEAKER_01: Think of this you're basaltic eruption, basaltic eruption, basaltic eruption, it's piling up, piling up, piling up.
12:48
SPEAKER_01: That basalt is interacting with water.
12:51
SPEAKER_01: It's interacting with glaciers, it's interacting with rainwater, snow, it's getting hydrated.
12:56
SPEAKER_01: There's minerals that are being formed that have water in them, and then you bury those.
13:00
SPEAKER_01: Those things are easier to melt.
13:02
SPEAKER_01: So if you add heat to that recipe, you can melt basalt.
13:06
SPEAKER_01: So the point here is extra heat means extra distillation of the crust, and extra distillation means more felsic rocks, which are these more violent personality types, the more violent volcanic rock types, or the more violent volcanoes, and then the more felsic rock types that come out of those.
13:21
SPEAKER_01: So it's really about more melting in Iceland, more volcanism that kind of feeds back into more distillation.
13:30
SPEAKER_01: The crustal package there is thicker and hotter, and therefore it gets melted more.
13:35
SPEAKER_01: And that's why there's more felsic rocks.
13:37
SPEAKER_00: Exactly.
13:37
SPEAKER_00: And I want to highlight what you said because I want to make sure everybody understands this.
13:42
SPEAKER_00: When you talk about the distillation of a mafic basaltic magma pile upon pile upon layer upon layer of this these eruptions, that extra heat then is going to partially melt and then partially melt and partially melt these mafic rocks.
14:02
SPEAKER_00: Well, again, this is another throwback to Bowen's reaction series, and we've given this several cracks on previous episodes of why is this so important?
14:10
SPEAKER_00: Well, here's a classic example of why Bowen's reaction series is is so important because when you partially melt mafic magma, what part are you melting?
14:21
SPEAKER_00: Not melting the whole thing.
14:22
SPEAKER_00: What part are you melting?
14:24
SPEAKER_00: And you're melting the lower temperature minerals in Bowen's reaction series, and these happen to be the quartzes and the feldspars and the muscovites, these lighter colored minerals, and these are what make magma sticky.
14:37
SPEAKER_00: So that's right.
14:38
SPEAKER_00: That's exactly what I'm saying.
14:39
SPEAKER_00: If you do this again and again and again and again, then you're gonna generate magma that is very different from the rock that it came from.
14:49
SPEAKER_00: If you melt basalt, you get basaltic magma.
14:53
SPEAKER_00: But if you partially melt it and then you partially melt it again, and you part you keep doing this, you keep on generating a magma that is very, very chemically different from the rock that's left behind.
15:08
SPEAKER_01: That's a really nice way to phrase it.
15:10
SPEAKER_01: If you melt basalt, you get basalt, but if you partially melt basalt, you get something intermediate or granite-like, because you're distilling it.
15:18
SPEAKER_01: You're taking out all the goodies that are easy to melt.
15:21
SPEAKER_01: It's like making maple syrup, or it's like making distilling alcohol.
15:25
SPEAKER_01: You distill the goodies out, and what's left behind has less goodies in it, and the the stuff that that comes out, then then you get a granitic rock.
15:34
SPEAKER_01: And so in Iceland, we have what's called a bimodal volcanic series where you have a lot of mafic stuff, and you have a decent amount of felsic stuff, and you have very little in the middle.
15:44
SPEAKER_01: There's not much in between those two compositions because you form basalt by melting the mantle, and then you melt the basalt and you get granite or dasuck or any kind of basalt, yep.
15:56
SPEAKER_01: You part uh right, thank you, thank you.
15:58
SPEAKER_01: You partially melt the mantle, you get basalt, you partially melt the basalt, and you get something felsic in composition that produces these more violent types of volcanic eruptions.
16:08
SPEAKER_00: And the last thing go ahead.
16:10
SPEAKER_00: I just can I interrupt a second, Jesse, because I had a thought, right?
16:13
SPEAKER_00: You're talking about all right, if I partially melt the mantle, I get basalt.
16:17
SPEAKER_00: You know, we did an episode recently on the rocks you should know, and then we did another episode on some of the rocks that you maybe don't know, but you should, and then we did an episode on like on common rocks, right?
16:28
SPEAKER_00: But yeah, the mantle is made of peridotite, it's ultramafic.
16:34
SPEAKER_00: And so one of the ones you should know.
16:37
SPEAKER_00: Yes, it is, yes, it absolutely is.
16:39
SPEAKER_00: And then if you partially melt peritotite, that's ultramafic.
16:43
SPEAKER_00: Now you generate basalt, which is just mafic.
16:47
SPEAKER_00: Okay.
16:47
SPEAKER_00: And then if you partially melt basalt, you generate an intermediate magma, and the common rock type that's associated with that is andesite or diurite, depends on whether it's intrusive or extrusive.
16:59
SPEAKER_00: And if you partially melt that, then you generate a granitic magma or a felsic magma.
17:05
SPEAKER_00: The two rock types are rhyolite and granite.
17:07
SPEAKER_00: So these are rock types that I think a lot of our audience are probably quite familiar with.
17:13
SPEAKER_00: I would hope anyway.
17:14
SPEAKER_00: If you're not, then well, you should go listen to our episodes.
17:17
SPEAKER_01: You know, go go to go listen to our episodes, go to the Camp Geo app and learn about the rock types there.
17:23
SPEAKER_01: Go to our igneous rocks chapter, learn about that.
17:26
SPEAKER_01: Chris, will you allow me a little rant about the early earth quickly?
17:30
SPEAKER_01: And then I want to hear what you're I I actually do.
17:33
SPEAKER_00: I want because you you started too early on, and I wanted to just say, let's come back to this because I think it's important.
17:40
SPEAKER_00: So let's talk about Iceland and what you said, I think is a really powerful statement that this may be a prototype for the formation of continents.
17:51
SPEAKER_00: And I think that's a really important and and really fun and cool aspect to dive into.
17:57
SPEAKER_01: So a little bit about Iceland, the sort of the structure of Iceland.
18:01
SPEAKER_01: We don't really know what's at depth beneath Iceland in the crust, but we know the thickness of the crust.
18:06
SPEAKER_01: So in oceanic crust, if you're not in Iceland, if you're in anywhere else in oceanic crust, the crust is about seven kilometers thick.
18:13
SPEAKER_01: So that's the basaltic layer that sits on top of the mantle and the mantle lithosphere there.
18:19
SPEAKER_01: So the crust is seven kilometers thick.
18:21
SPEAKER_01: In the continental crust, the crust is usually 35 to 70 kilometers thick, so a lot thicker.
18:28
SPEAKER_01: In Iceland, the crust is about 25 kilometers thick, so kind of intermediate, right?
18:33
SPEAKER_01: Kind of in between those two.
18:35
SPEAKER_01: And that's really unique to Iceland.
18:37
SPEAKER_01: There's not many places that have that intermediate thickness of crust.
18:40
SPEAKER_01: Now, Iceland also has a lot of basalt, 75% basalt, but maybe 25% granitic or felsic compositions of rocks on the surface, at least.
18:51
SPEAKER_01: And so Iceland is probably, you said a prototype for continental crust.
18:56
SPEAKER_01: Iceland today is unlikely to subduct.
18:59
SPEAKER_01: If Iceland gets thrown into a subduction zone system, it's gonna get glommed onto the edge of the continent.
19:04
SPEAKER_01: It's not gonna go down the subduction zone system because it's too buoyant.
19:08
SPEAKER_00: It's all about density and the introduction of these more felsic rocks like granitic magma or you know, rhyolite is the extrusive version of this, it's too buoyant.
19:19
SPEAKER_00: It can't get dragged down into a subduction zone.
19:22
SPEAKER_00: And so instead, to me, I don't know, like an I'm gonna try an analogy.
19:27
SPEAKER_00: We'll see if you like it.
19:28
SPEAKER_00: If you don't, then you can let me know and I'll stop using it.
19:30
SPEAKER_00: But I use it all the time in class.
19:31
SPEAKER_00: Is that you know, if you if you make fried eggs, let's say you make some bacon in a frying pan, you get some grease, and then you take the bacon off and you use that hot grease, you throw some eggs in it, right?
19:41
SPEAKER_00: You're gonna caramelize the bottom part of those eggs.
19:43
SPEAKER_00: They're gonna kind of burn a little bit, you know.
19:45
SPEAKER_00: You get the eggs out of there, but you got some crud left over in the bottom of the pan.
19:48
SPEAKER_00: Well, if you take that spatula and you turn it upside down and you just scrape the crud off the bottom of the pan, that's kind of what's gonna happen to this.
19:56
SPEAKER_00: Is that when this material meets another plate, it's not gonna be dragged down, it's just gonna be scraped off and plastered to that other plate that it's that it's converging with.
20:09
SPEAKER_00: I don't know.
20:10
SPEAKER_00: That's exactly right.
20:11
SPEAKER_00: Is that a good analogy or is that a big analogy?
20:12
SPEAKER_00: I like that analogy.
20:13
SPEAKER_01: No, that's a that's a good one.
20:14
SPEAKER_01: It's gonna get scraped off because it's not gonna get subducted, it's too buoyant, it's gonna get scraped off in its subduction zone system, right?
20:20
SPEAKER_01: And that is really important, especially if you consider just hypothetically, consider a planet without continents.
20:28
SPEAKER_01: And if you have a planet without continents, the question is how do you get a continent to form?
20:33
SPEAKER_01: How do you kickstart this process?
20:35
SPEAKER_01: Because it's kind of a difficult thing to potentially do.
20:38
SPEAKER_01: And the juxtaposition of a mid-ocean ridge and a mantle plume, where there's this extra heating, you get this kind of proto-continent.
20:45
SPEAKER_01: If you have a bunch of little icelands forming, then those could run into each other and nobody's gonna go down in the subduction zone system, and they could kind of grow into an actual continent.
20:55
SPEAKER_01: If you take these little proto-continents, these nuclei, and smash them into each other, they could eventually become a bigger thing that we would consider a continent.
21:04
SPEAKER_01: So that's why Iceland becomes an interesting analogy for how continents kind of got kickstarted.
21:09
SPEAKER_01: How do you kickstart continental growth?
21:11
SPEAKER_01: And one model that has been proposed before us, but that my PhD work kind of you know grabbed onto was this Icelandic analogy, like, hey, maybe this is the way you kind of kickstart continental growth is an Iceland-like place because it's this kind of intermediate, it's in between oceanic crust and continental crust, which is really rare on the modern earth, and it might be a good way to kind of kickstart this.
21:34
SPEAKER_01: So, okay, that's my little tangent on the earlier earth.
21:37
SPEAKER_00: Thank you for well, I I love that, but I have a thought.
21:40
SPEAKER_00: You have no idea what I'm gonna say right now.
21:42
SPEAKER_01: Okay, because I rarely have any idea what you're gonna say.
21:46
SPEAKER_00: That's true.
21:47
SPEAKER_00: Um Well, let's talk about the subcontinent of India before it collided with Eurasia and and shallowly was dragged underneath Eurasia and formed the Himalayan mountains.
21:59
SPEAKER_00: What what Formed India?
22:01
SPEAKER_01: Uh the southern tip of India is like really old.
22:03
SPEAKER_01: It's all Archean, deep crustal stuff that's been tilted up.
22:08
SPEAKER_01: So India is a piece of a it's a fragment of a supercontinent that's kind of been broken apart and kind of bopped around a little bit.
22:16
SPEAKER_01: I think it's more of a continent.
22:18
SPEAKER_01: It's an actual honest to goodness continent, whereas Iceland is kind of a new growth.
22:22
SPEAKER_01: It's a new little proto-continent.
22:25
SPEAKER_01: And when that runs into another continent, it's not going to create the Himalayas, it's not going to like double the thickness.
22:30
SPEAKER_01: It'll probably get kind of smushed onto the side a little bit in a in a lesson.
22:33
SPEAKER_01: Just kind of accreted to it, yeah.
22:35
SPEAKER_01: Maybe accreted, exactly.
22:37
SPEAKER_01: Much more like a volcanic arc that kind of gets accreted to the side.
22:40
SPEAKER_01: It's, I mean, still tectonically dramatic, but not as dramatic as the Himalayas, probably.
22:46
SPEAKER_00: So that's super interesting, and thanks for bringing us to that.
22:49
SPEAKER_00: Uh, there's an example, kind of a you know, not too far in the past example of one of these enormous, huge eruptions, cataclysmic eruptions in Iceland.
22:59
SPEAKER_00: And it happened in 1783, actually.
23:01
SPEAKER_00: This was Lockheed, and it caused a lot of devastation and massive amounts of loss of life.
23:07
SPEAKER_00: And this was a big deal.
23:09
SPEAKER_00: It led to a famine because of all the aerosols that were put in there, the dust and ash and the blotting out the sun and so on.
23:17
SPEAKER_00: About 25% of the island's population was lost.
23:21
SPEAKER_00: Can you imagine?
23:21
SPEAKER_00: Like, that's crazy, Jesse, to think about this, right?
23:24
SPEAKER_00: It actually affected global temperatures.
23:26
SPEAKER_00: It spewed sulfur dioxide into the northern hemisphere.
23:28
SPEAKER_00: And it was this was just a this was a big, big deal.
23:31
SPEAKER_00: They actually didn't know if the island was going to recover from this event.
23:34
SPEAKER_00: And this is really not too far removed, you know, 1783 into 1784.
23:40
SPEAKER_00: It was a basaltic kind of thing, but it started as really violent.
23:44
SPEAKER_00: As that's kind of typical too, because even if it's a basaltic eruption, you have a lot of gas.
23:49
SPEAKER_00: And so it kind of changes nature as it effuses and loses the gas, then it becomes more quiet, right?
23:55
SPEAKER_00: But it still put just tons of these toxic gases into the atmosphere.
24:00
SPEAKER_00: It's just not a good not a good thing.
24:02
SPEAKER_00: So um I mean, it's an interesting thing.
24:04
SPEAKER_01: We rarely think of Iceland as a volcanic hazard area, right?
24:08
SPEAKER_01: I mean, we we more think of the strato volcanoes, the Italian volcanoes, the Japanese volcanoes, the Cascades, the Andes.
24:16
SPEAKER_01: We don't necessarily very frequently think of Iceland in this regard, uh, but it is a major player.
24:21
SPEAKER_01: So, Chris, what is the how's the planning going?
24:25
SPEAKER_01: And what is I mean, maybe what's surprised you or what's interesting at this stage?
24:31
SPEAKER_01: And and let's keep it high level because we will go into the weeds a bit more later.
24:35
SPEAKER_01: But what I don't know, what are what's the stats?
24:37
SPEAKER_00: I guess what started it all, and Steve Maddox, professor at Grand Valley, he's the guy that I work very closely with.
24:42
SPEAKER_00: We've had him as a guest on our show, you know.
24:44
SPEAKER_00: Friend of the pod, friend of the pod.
24:46
SPEAKER_00: Yeah, he is a friend of the pod, and we um he sent me a video link just out of the blue, random.
24:52
SPEAKER_00: And he said, Check this out, wait till you get home, put it on a big screen, watch it with Jenny.
24:57
SPEAKER_00: And it was uh a half hour long video of a really talented photographer and videographer that was hiking one of the top five backpacking trails in the world, and it's called the Lagervegger Trail.
25:11
SPEAKER_00: And I was blown away.
25:13
SPEAKER_00: The scenery that he captured in this, and it's not very it's only like uh 40 miles, you know.
25:20
SPEAKER_00: But then I was really, really enthralled at that point after watching this with Jenny.
25:26
SPEAKER_00: And Jenny is, you know, Jenny was all in, and I'm like, well, let's let's look into this.
25:30
SPEAKER_00: And so that's how it all started.
25:31
SPEAKER_00: We decided to add on another 15 miles to it, and we're gonna we're gonna end up hiking a one-way trip from Landem on a lager through the Leg of Lager Vegar Trail, and we're gonna end at Scogar.
25:43
SPEAKER_00: So attacking another end onto it, but I can't wait.
25:47
SPEAKER_00: And it the planning is what's the geology?
25:50
SPEAKER_01: What's the geology that you're walking across?
25:52
SPEAKER_00: It's everything, Jesse.
25:54
SPEAKER_00: It you go through this diversity of volcanism.
25:56
SPEAKER_00: It's you have a lot of basalt, you have rhyolite, you have hydrothermal features and glaciers.
26:02
SPEAKER_00: All of them are involved, and then the side jaunts.
26:06
SPEAKER_00: This is why we're not gonna fly through this trail.
26:09
SPEAKER_00: We could do 55 miles in just a few days, right?
26:12
SPEAKER_00: If we wanted to.
26:14
SPEAKER_00: We're not gonna do that.
26:15
SPEAKER_00: We're only gonna go maybe seven or eight miles at a crack because when you camp, then you have all these side ventures that you can go on to and see just unbelievable geology.
26:26
SPEAKER_00: So we're planning that too.
26:27
SPEAKER_00: We're gonna get up, we're gonna hike to here, and then we're gonna pitch our tents and kind of go down to smaller packs and then book it to another place.
26:35
SPEAKER_00: That's gonna be our approach to it.
26:37
SPEAKER_00: So the first like eight days were backpacking in Iceland.
26:40
SPEAKER_01: Yeah, that's pretty cool.
26:42
SPEAKER_01: Very good.
26:42
SPEAKER_01: Very good.
26:43
SPEAKER_01: What's the what's the most exciting geological feature or the the thing that's that you're most excited about?
26:48
SPEAKER_01: Just one.
26:48
SPEAKER_01: You have to pick one.
26:49
SPEAKER_00: Do I have to pick one?
26:50
SPEAKER_00: Oh my gosh.
26:51
SPEAKER_00: I have a I have a flood of stuff going through my head right now.
26:55
SPEAKER_00: Um, I guess I really want to see and stand in the Rift Valley, you know, where the where the mid-ocean ridge runs right through Iceland.
27:07
SPEAKER_00: I'm looking forward to that, but there's so much, you know, like the I can't wait to see the all the Columnar joints, and I can't wait to see the original geyser.
27:17
SPEAKER_00: The one that all other geysers are named for.
27:19
SPEAKER_00: I I can't wait for that.
27:21
SPEAKER_00: And you know what, Else Jesse?
27:22
SPEAKER_00: I can't wait to see the puffins.
27:24
SPEAKER_00: The puffins in the fjords.
27:25
SPEAKER_00: I'm really looking forward to that.
27:27
SPEAKER_01: Totally.
27:27
SPEAKER_01: This is gonna be great.
27:28
SPEAKER_01: I'm super jealous.
27:29
SPEAKER_01: Oh man, that's that's pretty good.
27:32
SPEAKER_00: I did ask Steve, because Steve goes there a lot.
27:34
SPEAKER_00: He's taking a class there this summer.
27:36
SPEAKER_00: He's actually gonna be there when I'm there.
27:38
SPEAKER_00: I said, So have you ever seen the northern lights in Iceland during the summertime?
27:42
SPEAKER_00: And he's like, nah, it's it's kind of weird.
27:44
SPEAKER_00: It doesn't really get dark.
27:46
SPEAKER_00: It'll get kind of somewhat dark for a couple of hours, but the sun is just below the horizon, so it's still pretty light out.
27:53
SPEAKER_00: So unfortunately, won't get to see that probably, but that's the problem.
27:58
SPEAKER_01: We're gonna probably around the same time.
28:00
SPEAKER_01: You'll be in Iceland, and I'll be walking around Iceland-like rocks in the four billion-year-old rocks up in Acosta.
28:06
SPEAKER_01: It's the same problem up there.
28:08
SPEAKER_01: You know, it's just light too long to see the northern lights, really.
28:11
SPEAKER_01: Like it never really gets dark.
28:12
SPEAKER_01: So that's the problem.
28:14
SPEAKER_01: You're debating whether going early July or late August.
28:17
SPEAKER_01: In August, you can for sure see it, but not in early.
28:20
SPEAKER_00: Have you ever been there during non-peak season?
28:23
SPEAKER_00: I mean, peak season being in the you know, the warmest and best potential for good weather.
28:27
SPEAKER_00: Like, have you ever been there in a time outside of that?
28:30
SPEAKER_01: Oh, yeah.
28:30
SPEAKER_01: Um, I've been up there in the wintertime.
28:32
SPEAKER_01: Well, to Yellowknife in the wintertime, not up like outside of civilization, but up in Yellowknife in the wintertime, and it's cold and the northern lights are out every night.
28:39
SPEAKER_01: Uh so are they really?
28:41
SPEAKER_00: So it's like, okay, all right, that's awesome.
28:43
SPEAKER_00: Are they colorful?
28:45
SPEAKER_01: You know, I've seen the green and yellow combination a lot, but the reds I've only seen once.
28:49
SPEAKER_01: Like the green reds I've only seen once in a really like spec the the sort of stunning, spectacular way.
28:55
SPEAKER_01: So they're they're a little bit more rare, but you know, if you're up there for a week, you'll probably see them.
29:00
SPEAKER_01: Yeah.
29:00
SPEAKER_01: Well, okay, Chris.
29:02
SPEAKER_01: Iceland's very cool.
29:03
SPEAKER_01: Iceland's very unique.
29:04
SPEAKER_01: Iceland's a geologist's dream to go to.
29:08
SPEAKER_01: It's one of the bucket list places in many geologists' minds.
29:11
SPEAKER_01: And uh myself and probably many of our listeners are very jealous of you.
29:14
SPEAKER_01: So, you know, take lots of pictures of the cool rocks and cool stuff for us.
29:19
SPEAKER_01: And uh we'll we'll have an update here as we get closer to your trip or maybe after your trip, too, where we get more into the weeds about Icelandic geology because it is just so cool and so unique, and just geologists, we study stuff that's kind of outlier.
29:35
SPEAKER_01: We we study the ones that are weird, and Iceland's one of the weird ones.
29:39
SPEAKER_01: It's the only place that looks like Iceland geologically, and that's cool, right?
29:44
SPEAKER_00: Yeah, I can't wait.
29:45
SPEAKER_00: I'm super excited.
29:46
SPEAKER_00: But I we've talked about this in another episode too.
29:48
SPEAKER_00: I love the planning part of it though.
29:50
SPEAKER_00: I'll tell you though, with this one it's difficult for me, more difficult than normal, because the challenge for me is I want to find places that are of geologic interest and not tourist interest.
30:04
SPEAKER_00: I'm not a I'm not a boardwalk kind of guy, and you know, so I want to make sure that we get away and and see things that most people probably won't see.
30:16
SPEAKER_00: So that's challenging though, because when you when you're looking around online, like we said, you know, finding these field guides and okay, you have to go here because you're gonna see this, and it's just not very common to find that stuff online.
30:31
SPEAKER_00: You do these searches and you come across where everybody goes to this.
30:34
SPEAKER_00: It's proven to be a challenge, but it's a fun challenge.
30:37
SPEAKER_01: Do the deep dives into the the sort of difficult to find literature.
30:40
SPEAKER_01: So that's super exciting.
30:41
SPEAKER_01: Well, Chris, I I can speak for uh a bunch of people.
30:44
SPEAKER_01: We're very excited for you and uh can't wait to hear how how it goes.
30:48
SPEAKER_01: So, hey, that's a wrap for this episode.
30:50
SPEAKER_01: If you have any questions, send us an email, planetegeocast at gmail.com.
30:53
SPEAKER_01: We love getting those.
30:54
SPEAKER_01: We got a bunch recently that you know we're gonna we're building episodes on the packs of.
30:58
SPEAKER_01: So stay tuned if you gave us a question and we haven't responded or gotten back to you in a while.
31:04
SPEAKER_01: Give us a break.
31:04
SPEAKER_01: We're we'll get to it eventually.
31:06
SPEAKER_01: Um, if you want to learn more with images, geology is just such a visual science.
31:10
SPEAKER_01: You can go to our Camp Geo mobile app.
31:13
SPEAKER_01: It's the first link in the show notes.
31:14
SPEAKER_01: There we have a whole bunch of free content.
31:16
SPEAKER_01: Basically, the introduction to college-level geology that Chris and I both teach is there, along with some other audiobooks on the Grand Canyon, the Tetons will be up soon, and the geology of Yellowstone.
31:28
SPEAKER_01: So go check that out, and you can follow us on all the social medias at Planet Geocast.
31:33
SPEAKER_01: Cheers.