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Why is Water "Hard"? · PlanetGeo: The Geology Podcast

• 0:03
  SPEAKER_01: Welcome to Planet Geo, the podcast where we talk about our amazing planet, how it works, and why it matters to you.
• 0:14
  SPEAKER_01: Chris, I got a question for you, man.
• 0:17
  SPEAKER_01: Yeah.
• 0:18
  SPEAKER_01: So go ahead.
• 0:19
  SPEAKER_01: Just in general, when Michigan, I know you're a big football fan, and you used to be, at least when in a in a past life, you used to be a pretty diehard University of Michigan fan.
• 0:29
  SPEAKER_01: Is that still the case?
• 0:31
  SPEAKER_00: I I do.
• 0:31
  SPEAKER_00: I like Michigan.
• 0:32
  SPEAKER_00: You know, I'm all about the state of Michigan, right?
• 0:34
  SPEAKER_00: So anybody that is playing from Michigan, nobody's rooting for.
• 0:38
  SPEAKER_01: Nobody's allowed to say anything bad about Michigan in front of Crispy.
• 0:42
  SPEAKER_01: That's what's definitely one rule.
• 0:45
  SPEAKER_00: But if Michigan and Michigan State are playing, then I'm pulling for Michigan.
• 0:48
  SPEAKER_01: Okay.
• 0:49
  SPEAKER_00: So that's kind of how that goes.
• 0:50
  SPEAKER_00: Does that make sense?
• 0:51
  SPEAKER_01: Yeah, that makes sense.
• 0:52
  SPEAKER_01: What what do you feel when one of the teams plays Penn State?
• 0:56
  SPEAKER_00: Uh so I have to do that.
• 0:58
  SPEAKER_00: Are you at all conflicted because of me or not?
• 1:00
  SPEAKER_00: I am.
• 1:00
  SPEAKER_00: Yeah.
• 1:01
  SPEAKER_00: I am.
• 1:01
  SPEAKER_00: I actually am.
• 1:02
  SPEAKER_00: Yeah, I am.
• 1:02
  SPEAKER_00: Yep.
• 1:02
  SPEAKER_00: I pull for Penn State because of you.
• 1:05
  SPEAKER_00: Okay.
• 1:05
  SPEAKER_00: I do.
• 1:06
  SPEAKER_00: Well, there we go.
• 1:06
  SPEAKER_00: Yeah.
• 1:07
  SPEAKER_00: We've acquired a new fan here.
• 1:11
  SPEAKER_00: I mean, everybody that I've met from Penn State, you know, Lee Cump, I met him, and and just great people.
• 1:17
  SPEAKER_00: So they're a lot like Michigan people, I think.
• 1:20
  SPEAKER_01: Yeah, I think so.
• 1:21
  SPEAKER_01: I think so.
• 1:21
  SPEAKER_01: And a lot different than Wisconsin people and you know, Illinois people and Indiana people.
• 1:26
  SPEAKER_01: Oh.
• 1:28
  SPEAKER_01: A bunch of, you know, anybody who I work with who's not really from the Midwest and doesn't really know anything about the Midwest, they're like, oh, well, you're from like Minnesota, aren't you, or something?
• 1:37
  SPEAKER_01: And I was like, oh no, Michigan.
• 1:39
  SPEAKER_01: And they're like, oh, okay, well, whatever.
• 1:40
  SPEAKER_01: And I'm like, no, no, no.
• 1:42
  SPEAKER_01: Hold on.
• 1:43
  SPEAKER_01: The Midwestern states, we're so similar, we have to hate each other.
• 1:46
  SPEAKER_01: You know, like we hate Wisconsin.
• 1:47
  SPEAKER_01: And the reason is we're so similar to Wisconsin, really, you know, but way better.
• 1:51
  SPEAKER_01: Obviously.
• 1:52
  SPEAKER_00: Wisconsin wants to rename Lake Michigan Lake Wisconsin.
• 1:55
  SPEAKER_00: And I have I have some serious problems with that.
• 1:58
  SPEAKER_01: Yeah, I mean, they're wrong.
• 1:59
  SPEAKER_01: So it's stupid idea.
• 2:01
  SPEAKER_01: Okay.
• 2:01
  SPEAKER_01: Stupid idea.
• 2:04
  SPEAKER_01: No, that's our lake.
• 2:05
  SPEAKER_01: Shut up.
• 2:06
  SPEAKER_00: Yeah.
• 2:06
  SPEAKER_00: You know, I don't I don't know if we've ever talked about this, but one of the times we were on a trip and we were coming back into or driving back in, and you enter Michigan, and it says something, there's a big sign, and it says the Great Lakes State, right?
• 2:18
  SPEAKER_00: And Jenny says, Oh, it's so good to be back home.
• 2:21
  SPEAKER_00: And somehow we turned our discussion to the Great Lakes, and she's like, Well, there are lakes.
• 2:27
  SPEAKER_00: Yeah.
• 2:27
  SPEAKER_00: And I'm like, What do you mean?
• 2:29
  SPEAKER_00: She's like, Well, they belong to us.
• 2:31
  SPEAKER_00: Meaning Michigan?
• 2:32
  SPEAKER_00: Yeah, meaning Michigan.
• 2:33
  SPEAKER_00: And I'm like, well, not really, Jen.
• 2:35
  SPEAKER_00: And she's like, what?
• 2:37
  SPEAKER_00: She was truly dumbfounded that that's all I think that's a lot of Michiganders feel that way.
• 2:43
  SPEAKER_00: I mean, this is our water.
• 2:45
  SPEAKER_01: We're kind of just BSing around this.
• 2:46
  SPEAKER_01: But I this actually ties into the episode we're going to talk about in a tendential way.
• 2:51
  SPEAKER_01: But Chris, I felt the same way when I moved to Canada.
• 2:53
  SPEAKER_01: You know, growing up in Michigan, we think of the five Great Lakes, right?
• 2:56
  SPEAKER_01: You know, you've got the ones that surround Michigan, Iran, Ontario, Michigan, Erie, Superior.
• 3:01
  SPEAKER_01: Those are the five Great Lakes.
• 3:03
  SPEAKER_01: But you move to Canada, and they're like, no, no, no, no.
• 3:06
  SPEAKER_01: There are a lot more Great Lakes because they extend all the way up, right?
• 3:09
  SPEAKER_01: You Great Bear Lake, Great Slave Lake, Lake Winnipeg, like huge Lake Athabasca, huge lakes.
• 3:15
  SPEAKER_01: I mean, they're actually I think Great Slave Lake is the deepest lake.
• 3:19
  SPEAKER_01: They're huge.
• 3:20
  SPEAKER_01: And so Canadians get a little worried when we only talk about the five Great Lakes that are on the border of the U.S.
• 3:26
  SPEAKER_00: In fact, Jesse, like I didn't even know this until you started talking about how big these lakes were and the amount of water that's held in them.
• 3:34
  SPEAKER_00: It's amazing.
• 3:35
  SPEAKER_01: But it's a cool feature.
• 3:36
  SPEAKER_01: You can look at the map.
• 3:37
  SPEAKER_01: It's like river networks.
• 3:39
  SPEAKER_01: You can look at the water distribution system where water is on the planet, and you can tell the underlying geology by that.
• 3:46
  SPEAKER_01: Because where the shield, the hard basement rocks, the canyon shield, hit the soft sediments of the interior, that's where the Great Lakes are.
• 3:53
  SPEAKER_01: All of them.
• 3:54
  SPEAKER_01: And they just follow this beautiful line.
• 3:55
  SPEAKER_01: And uh it's a really cool example of that.
• 3:58
  SPEAKER_01: And Chris, let's transition because we're talking about hard water here this episode, which uh I don't know, it's tangential to lakes and great lakes a little bit.
• 4:08
  SPEAKER_00: It is, it absolutely is.
• 4:09
  SPEAKER_00: But you might be wondering, because this is in our series of climate, right?
• 4:13
  SPEAKER_00: And and why would we do an episode devoted to hard water and salty oceans when we're talking about climate?
• 4:21
  SPEAKER_00: And we need to make sure that we bring that connection home.
• 4:24
  SPEAKER_00: And I think that's a good place to start.
• 4:27
  SPEAKER_01: I agree.
• 4:27
  SPEAKER_01: So let's just run through an overview of what we're gonna cover.
• 4:30
  SPEAKER_01: But before we get to that, if you listen to this on the podcast, you can find this episode with a couple others that we've released with all the images in a climate book that you can buy for a couple bucks on our Camp Geo app.
• 4:42
  SPEAKER_01: So the first link in your show notes is the Camp Geo app.
• 4:44
  SPEAKER_01: Go there, download that, and you can get access to this climate series that we have with all the key images that you need and some extra content that you're not getting on the podcast.
• 4:53
  SPEAKER_01: And you can also purchase access to our Yellowstone book and our Geology of Grand Canyon book as well, and the Camp Geo Introduction to Earth Sciences that is still for free.
• 5:02
  SPEAKER_01: So, anyway, point there if you're listening to this on the podcast.
• 5:05
  SPEAKER_01: So, Chris, let's just review here or give an overview of what we're gonna cover.
• 5:10
  SPEAKER_01: We're gonna talk about really hard water.
• 5:12
  SPEAKER_01: What is really the the question is what are salts in water?
• 5:15
  SPEAKER_01: What does that mean?
• 5:16
  SPEAKER_01: What is a salt in water?
• 5:17
  SPEAKER_01: Where do they come from?
• 5:19
  SPEAKER_01: And this really, I think, interesting question that I think a lot of very informed, very smart people have never thought of.
• 5:27
  SPEAKER_01: And if they have thought of it, they kind of ponder it and don't spend too much time on it, which is why are the oceans salty and lakes not?
• 5:34
  SPEAKER_01: That's one of the key pieces here.
• 5:36
  SPEAKER_01: And then, you know, as part of that is the role of groundwater and rivers, and then coming back to sort of hard water, quote unquote hard water, why we call it hard.
• 5:44
  SPEAKER_01: But it fits in this series on climate because we're really talking about weathering.
• 5:48
  SPEAKER_01: This is the weathering process that has a huge control on the concentration of carbon dioxide in your atmosphere, is one potential solution to climate change, and you know, is part of this carbon cycle, the slow, long, fun, interesting rock-based carbon cycle.
• 6:02
  SPEAKER_00: And carbon plays a very important role in this chemical weathering process because carbon dioxide combines with water in the atmosphere to create this weak acid.
• 6:12
  SPEAKER_00: And then that weak acid goes to work on rocks, dissolving them selectively.
• 6:18
  SPEAKER_00: Certain things get dissolved better.
• 6:19
  SPEAKER_00: We're gonna talk about this, and then it brings these ions via rivers and via groundwater to the oceans.
• 6:25
  SPEAKER_01: And so So, Chris, can we just define hard water?
• 6:29
  SPEAKER_01: And let's give an example.
• 6:30
  SPEAKER_01: You live a little bit out in the country, at least on a couple acres.
• 6:34
  SPEAKER_01: What how many acres do you have?
• 6:35
  SPEAKER_01: Seven, is that right?
• 6:36
  SPEAKER_00: Five acres.
• 6:37
  SPEAKER_01: Five acres.
• 6:37
  SPEAKER_01: Okay.
• 6:38
  SPEAKER_01: But you have well water, is that right?
• 6:39
  SPEAKER_00: Yes, I do.
• 6:40
  SPEAKER_01: Yep.
• 6:40
  SPEAKER_01: And is it hard?
• 6:41
  SPEAKER_01: Quote unquote.
• 6:42
  SPEAKER_01: It is hard water for sure.
• 6:43
  SPEAKER_00: Yeah.
• 6:44
  SPEAKER_00: It's it's got a lot of uh got a lot of iron in it, and it has the that's some that's an interesting thing, Jesse.
• 6:49
  SPEAKER_00: Is I think when people think of hard water, they think of iron in the water.
• 6:54
  SPEAKER_00: But I think it's because they think metal and metals are hard, and you know, the this misconception comes from, I think.
• 7:02
  SPEAKER_01: Yeah, that's interesting.
• 7:03
  SPEAKER_01: Okay, and so hard, quote unquote, uh the term is used because it's it's hard to like get soap to lather with it, right?
• 7:10
  SPEAKER_01: That's right.
• 7:11
  SPEAKER_01: That's that's where the term hard comes from.
• 7:13
  SPEAKER_01: But what it really means is that there's a lot of stuff dissolved in the water.
• 7:16
  SPEAKER_01: And the important ions for this purpose are calcium and magnesium.
• 7:19
  SPEAKER_01: Iron is another one that is in that water.
• 7:22
  SPEAKER_01: We live in Pennsylvania and we have we have city water, but it's hard.
• 7:25
  SPEAKER_01: Like our water, we live in a limestone karst topography where the water is just hard all over the place.
• 7:32
  SPEAKER_00: I think we need to take a step back a second and just talk about salt because it's salt that's in the water that is what makes the water hard.
• 7:40
  SPEAKER_00: But I think a lot of people, anyway, maybe not our audience, because our audience is so smart, and I mean that seriously.
• 7:46
  SPEAKER_00: Just the best, just the best.
• 7:47
  SPEAKER_00: Um, yeah, they're the best.
• 7:48
  SPEAKER_00: But salt is a reference to ions that are in the water.
• 7:52
  SPEAKER_00: It's not just sodium chloride.
• 7:54
  SPEAKER_00: In fact, those are not the ions that are, those aren't the ions that make the water hard to begin with.
• 8:01
  SPEAKER_00: It's more calcium and carbonate ions that are in the water that prevent the soap from lathering.
• 8:07
  SPEAKER_00: And if soap won't lather, then it can't do its job, which is clean.
• 8:11
  SPEAKER_00: And so we call it hard water for that reason.
• 8:13
  SPEAKER_00: But salts is a reference to a whole just stuff that is dissolved in the water in ion form.
• 8:20
  SPEAKER_01: That's right.
• 8:21
  SPEAKER_01: It makes it hard to lather.
• 8:22
  SPEAKER_01: And so the question, Chris, we're gonna come to is where did these ions come from?
• 8:25
  SPEAKER_01: Where do this calcium, magnesium, and the the bicarbonate, where does that come from?
• 8:30
  SPEAKER_01: And the key here is silicate rock.
• 8:32
  SPEAKER_01: That's really the key.
• 8:33
  SPEAKER_01: It's calcium, silica, oxygen, or magnesium, calcium, silica, oxygen.
• 8:38
  SPEAKER_01: There's a ton of minerals, again, that have that composition, but those things break down and they're easier to break down because that's kind of a mantle-e composition.
• 8:46
  SPEAKER_01: Lots of magnesium, lots of calcium, a little bit of silica.
• 8:49
  SPEAKER_01: That's kind of an olivine or pyroxene type thing.
• 8:51
  SPEAKER_01: Those break down, release those ions into the water system, which then work their way through the water system.
• 8:58
  SPEAKER_00: And uh a few of the really important ions that are gonna get brought to the oceans are these calcium ions, the magnesium ions, and importantly too, bicarbonate ions, they all get brought to the ocean where organisms, marine organisms, are gonna take those calcium ions, they're gonna take the bicarbonate anions, and they're gonna use it to make their shells, and it's turned into calcium carbonate, CACO3.
• 9:26
  SPEAKER_00: And that's the main component of the mineral calcite, it's the main component of the rock limestone.
• 9:31
  SPEAKER_00: So these ions get brought to the ocean.
• 9:34
  SPEAKER_00: Organisms use it.
• 9:35
  SPEAKER_00: These organisms live, they die, and they settle down on the ocean floor, forming rocks, removing carbon and putting it into the slow carbon cycle that we've talked about a couple episodes before.
• 9:47
  SPEAKER_01: Yes, that's exactly right.
• 9:49
  SPEAKER_01: It's such a key process.
• 9:50
  SPEAKER_01: I mean, it's just I I it's hard to overstate this process, I think.
• 9:56
  SPEAKER_01: And I don't know, Chris.
• 9:58
  SPEAKER_01: I I have a hard time like not belaboring this point in class a little bit.
• 10:02
  SPEAKER_01: I don't have the time to really spend a ton of time on it, but I like it's hard for me to like stay out of the weeds and not get overly excited and and not get like too down into it because it's just so important.
• 10:12
  SPEAKER_00: Well, okay, so let's talk about that.
• 10:14
  SPEAKER_00: What do you do?
• 10:15
  SPEAKER_00: How do you bring this topic up in your classes?
• 10:19
  SPEAKER_00: And then I'll talk about like what I do and why I think this is so important as well.
• 10:23
  SPEAKER_00: And also, Jesse, you don't have to tamp down your excitement.
• 10:26
  SPEAKER_00: Like no, it's excited, Jesse is fun, Jesse.
• 10:30
  SPEAKER_01: I know it's true, but excited Jesse is also a little bit rambly, Jesse.
• 10:34
  SPEAKER_01: So we we have to tone that part down.
• 10:37
  SPEAKER_01: Um, I the way I do it here, Chris, is because uh, you know, we're in we're in Pennsylvania, central Pennsylvania, and uh we have a lot of what are called spring creeks here.
• 10:44
  SPEAKER_01: And these are sort of karst creeks.
• 10:46
  SPEAKER_01: We've talked about that in the podcast a bunch before, but we're sort of in a limestone rich area where water's flowing through the groundwater system, it's picking up ions, and those things are flowing into the rivers in the valleys.
• 10:57
  SPEAKER_01: I come at it from a trout fishing side because the the spring-fed creeks are really, really biologically super active rivers, and so they get the trout get big.
• 11:07
  SPEAKER_01: It's really great fly fishing area in this part of Pennsylvania because of that, because there's so many ions in the water.
• 11:13
  SPEAKER_01: And so I kind of come at it from like, hey, great fly fishing.
• 11:16
  SPEAKER_01: Look at these beautiful rivers we have here in this area.
• 11:18
  SPEAKER_01: Why is it so good here?
• 11:20
  SPEAKER_01: And then that leads me into ions in the water.
• 11:22
  SPEAKER_01: Why are the ions in the water?
• 11:24
  SPEAKER_01: Well, we got a bunch of limestone, a lot of rocks dissolving and going into the river system.
• 11:28
  SPEAKER_01: Sure.
• 11:28
  SPEAKER_01: How do you sort of tackle that?
• 11:30
  SPEAKER_00: Well, I come at it usually when I'm talking about rivers and groundwater.
• 11:34
  SPEAKER_00: And I just ask the question because I think it's something that a lot of people and keep in mind, I'm I'm teaching high school kids, right?
• 11:41
  SPEAKER_00: 14 years old, up to 18 years old.
• 11:43
  SPEAKER_00: And I ask them, have you ever sat along the banks of a large river?
• 11:48
  SPEAKER_00: You know, whether that be the Grand River here running right through Michigan or the Mississippi River, the Missouri River, just a big river, right?
• 11:54
  SPEAKER_00: You sit along it, and this water just goes by, you know, it just never stops.
• 12:00
  SPEAKER_00: And you at some point, if you're a curious person, you have to wonder where is all this water coming from, right?
• 12:06
  SPEAKER_01: Yeah.
• 12:06
  SPEAKER_00: And so we talk about that because it's it's this common curiosity question, I think.
• 12:12
  SPEAKER_00: If you're a curious person, it's one of these things that you think about.
• 12:14
  SPEAKER_00: And then I use that to talk about another common curiosity question, which is why are the oceans salty?
• 12:21
  SPEAKER_00: Because they've all swam in our lakes, right?
• 12:23
  SPEAKER_00: I mean, most of my kids I've I did have one student a while back who 17-year-old girl, a Hudsonville born and raised girl that had never been to any of the Great Lakes before.
• 12:33
  SPEAKER_01: Wow, 20 minutes down the road.
• 12:35
  SPEAKER_01: That's a that's uh amazing.
• 12:37
  SPEAKER_01: Yeah.
• 12:37
  SPEAKER_00: Yes, we we solved that problem.
• 12:39
  SPEAKER_00: Okay.
• 12:40
  SPEAKER_00: But um anyway, they've noticed then, because most of our kids have also been into the ocean, and you know, they go south on spring break or whatever, right?
• 12:48
  SPEAKER_00: And you can't help but notice that the oceans are really, really salty and our lakes are not.
• 12:54
  SPEAKER_00: Okay, well, why is that?
• 12:56
  SPEAKER_01: What do they say to that, Chris?
• 12:57
  SPEAKER_01: Because I, you know, as I said before, we've I've come across very smart, very knowledgeable, very highly educated people who who haven't really thought of this, who haven't been had that had that question, that juxtaposition posed to them.
• 13:09
  SPEAKER_01: So what do your students say?
• 13:10
  SPEAKER_00: Do you ask that your students that?
• 13:12
  SPEAKER_00: Do you have them like just raise their hands?
• 13:13
  SPEAKER_00: How many of you have ever thought about this before?
• 13:15
  SPEAKER_01: I mean, I kind of do, but I've also uh by the time I ask them that, I've kind of given away the the given away the ghost.
• 13:21
  SPEAKER_01: I've sort of given them all the information they need to answer the question.
• 13:23
  SPEAKER_01: So it's not a fair, like pure ask, I suppose.
• 13:26
  SPEAKER_00: Okay.
• 13:26
  SPEAKER_00: I ask at the outset.
• 13:28
  SPEAKER_00: How many of you have thought about what you know why the rivers flow, right?
• 13:31
  SPEAKER_00: I just ask.
• 13:31
  SPEAKER_00: And then how many of you have thought about why oceans are salty and our lakes are not?
• 13:35
  SPEAKER_00: And I'd say maybe half of them have asked that question to themselves.
• 13:38
  SPEAKER_00: Oh, good, okay.
• 13:39
  SPEAKER_00: And then some of them are looking at me like I have a horn grown out of my head.
• 13:42
  SPEAKER_00: Like, what?
• 13:43
  SPEAKER_00: What why would I think about that?
• 13:44
  SPEAKER_00: You know, uh, they're just not curious.
• 13:46
  SPEAKER_00: Uh I don't know, whatever.
• 13:48
  SPEAKER_00: But we think about this, right?
• 13:49
  SPEAKER_00: I give them time to think about this.
• 13:51
  SPEAKER_00: And the most common answer I get, which is actually a really smart answer, they say it's because of the rocks in the ocean.
• 14:00
  SPEAKER_00: The ocean has different rocks than the lakes do.
• 14:03
  SPEAKER_01: Okay, so they've flipped it.
• 14:05
  SPEAKER_01: They flipped it in their mind.
• 14:06
  SPEAKER_01: Yeah, okay.
• 14:07
  SPEAKER_01: Yes, they're got they that's interesting.
• 14:09
  SPEAKER_01: They've got the cart and the horse.
• 14:10
  SPEAKER_01: They just got the cart before the horse.
• 14:12
  SPEAKER_01: That's right.
• 14:13
  SPEAKER_01: They do.
• 14:14
  SPEAKER_01: Interesting.
• 14:14
  SPEAKER_01: Hey, that's that's good though.
• 14:15
  SPEAKER_01: I mean, that that's really insightful.
• 14:16
  SPEAKER_01: So then do you follow up and say, why?
• 14:18
  SPEAKER_01: You know, why is Lake Michigan not depositing limestone or something like that?
• 14:22
  SPEAKER_00: Well, they know that they know that there's no limestone in Lake Michigan, and so that's I think maybe what leads them down that path.
• 14:29
  SPEAKER_00: And they say that the rocks are different in the oceans, and that's what makes the ocean salty, which is really good logic, but it's just backwards.
• 14:37
  SPEAKER_00: The rocks are there because the oceans are salty, not the other way around.
• 14:42
  SPEAKER_01: Oh, Chris, and this is the key part, you know, when you're sitting by a river, and this is what I do now, you know, now that and I think you do this too, now that we know this fact about the earth, is that the key here is that rivers and lakes like Lake Michigan have an outlet.
• 14:58
  SPEAKER_01: They're flowing out somewhere, and so water doesn't aggregate there that long, really.
• 15:04
  SPEAKER_01: And what do rivers have in them?
• 15:06
  SPEAKER_01: Well, they have salt in them, and we'll come back to this later on.
• 15:09
  SPEAKER_01: Well, where's that salt going?
• 15:10
  SPEAKER_01: Well, it's flowing downhill, it's going into a lake, maybe Lake Michigan, then it's going out the St.
• 15:14
  SPEAKER_01: Lawrence Seaway, eventually hitting the Atlantic Ocean.
• 15:16
  SPEAKER_01: Well, what happens there?
• 15:17
  SPEAKER_01: There's no outlet to the ocean, there's no way for water to get out.
• 15:20
  SPEAKER_01: The only way that water gets out is by distillation or evaporation from the surface into the atmosphere and then starts the water cycle over again.
• 15:28
  SPEAKER_01: Well, salt doesn't evaporate.
• 15:30
  SPEAKER_01: So it's all about the outlet.
• 15:32
  SPEAKER_01: That's the key difference.
• 15:34
  SPEAKER_01: The ocean has no outlet, lakes do.
• 15:35
  SPEAKER_00: And rivers the only way that water's gonna leave the ocean, because that is the ultimate basin, is by evaporation.
• 15:41
  SPEAKER_00: And when evaporation takes place, anything that's in the water stays behind and the water leaves.
• 15:47
  SPEAKER_00: And so aggregate that over time and the oceans then are gonna get saltier and saltier and saltier.
• 15:54
  SPEAKER_00: But this begs the question, Jesse.
• 15:56
  SPEAKER_00: They're like, wait a minute, rivers are not salty.
• 15:59
  SPEAKER_00: You know, everybody knows this.
• 16:00
  SPEAKER_00: And you're saying that the the oceans get salty because rivers are dumping salt into them, but yet the rivers are not salty.
• 16:08
  SPEAKER_00: So then we need to tackle that.
• 16:10
  SPEAKER_01: So, Chris, this brings up a really interesting historical uh uh fact that back in the day in sort of the late 1800s, early 1900s, when we were still having a significant amount of debate about the age of the earth.
• 16:24
  SPEAKER_01: Let's ignore the sort of religious side, first of all, but the scientific community was debating about a couple tens of millions of years old or like billions of years old.
• 16:32
  SPEAKER_01: We didn't really know.
• 16:33
  SPEAKER_01: People use this process to try and calculate the age of the earth because you can see how this might be a clock.
• 16:38
  SPEAKER_01: Rivers have some salt in them, it's a little bit, but they're flowing into the ocean, and the ocean has no outlet.
• 16:45
  SPEAKER_01: So you could see how this is kind of like a sand dial now.
• 16:48
  SPEAKER_01: We know the amount of salt coming out of rivers, we can measure that kind of broadly.
• 16:51
  SPEAKER_01: They could measure it back then.
• 16:53
  SPEAKER_01: We know the amount of salt in the ocean, which is a lot higher.
• 16:56
  SPEAKER_01: So, how long did it take for the rivers to deliver all of the salt to the ocean?
• 17:02
  SPEAKER_01: And what they calculated is a number that's a couple hundred million years.
• 17:05
  SPEAKER_01: Yeah, it's flawed logic though.
• 17:07
  SPEAKER_01: Well, I find it an amazing piece of logic that the number they got is not the age of the earth, the number they got is something different.
• 17:16
  SPEAKER_00: Here's where I'm saying that it's flawed logic is because when the oceans get saturated in salts, uh, they're gonna lay down rocks.
• 17:25
  SPEAKER_00: And so it's not as if rivers are bringing salts to the oceans, it's not as if in 10 million years the oceans are gonna be saltier than they are now.
• 17:32
  SPEAKER_00: They get to a certain point and they start to lay down rocks like limestone and dolestone and things like this that are removing the salt from the water.
• 17:41
  SPEAKER_00: And that's where I said it is great logic, but it's flawed.
• 17:44
  SPEAKER_01: Though absolutely right.
• 17:45
  SPEAKER_01: So what they calculated is something more akin to the residence time of salt in the ocean, which it's not really the residence time, but it's something more akin to that than the age of the earth or the ages of the oceans, for instance.
• 17:56
  SPEAKER_01: That calculation highlights the point here is that where do we get our ions from?
• 18:00
  SPEAKER_01: Well, they're in rivers.
• 18:01
  SPEAKER_01: We can trace them, we know they're in rivers, but where are they ultimately coming from?
• 18:05
  SPEAKER_00: I was just gonna say we need to back out of this and talk about where the salts that end up in the rivers come from.
• 18:11
  SPEAKER_00: And that leads to a discussion about groundwater, which this is kind of the way and the reason I do this in my class, because logically it makes sense, right?
• 18:21
  SPEAKER_00: Why do rivers continue to flow even during long serious drought situations?
• 18:27
  SPEAKER_00: It's because they're being fed by groundwater, which is a much, much, much larger source of where the world's water is.
• 18:35
  SPEAKER_00: So most rivers are fed by groundwater, and therefore the salts that rivers contain are getting to them from the groundwater.
• 18:47
  SPEAKER_00: So let's talk about that, Jesse.
• 18:49
  SPEAKER_00: Why does groundwater have a better ability to dissolve things and put things in solution?
• 18:55
  SPEAKER_00: What's happening with that?
• 18:56
  SPEAKER_01: Yeah, so Chris, it has to do with the rocks and the sort of time that the water's in contact with rocks.
• 19:02
  SPEAKER_01: And so the key here is groundwater.
• 19:04
  SPEAKER_01: You kind of need to think what makes chemical reactions progress, because we're talking about dissolving rock.
• 19:08
  SPEAKER_01: That's a chemical reaction.
• 19:09
  SPEAKER_01: So what makes chemical reactions go to completion?
• 19:13
  SPEAKER_01: And they need time.
• 19:14
  SPEAKER_01: Either you need to heat it up, right?
• 19:16
  SPEAKER_01: Heat makes reactions go faster, or you need time, you need longer time, you need to stir the solution longer.
• 19:22
  SPEAKER_01: I always think back to like, you know, high school chemistry or college chemistry where okay, you take some green solution, yellow solution, mix it together, try and get some purple solution out of it or whatever, right?
• 19:30
  SPEAKER_01: And there's a chemical reaction, you gotta stir it.
• 19:32
  SPEAKER_01: So you gotta stir it, you gotta take time.
• 19:34
  SPEAKER_01: And the the thing here is that streams, they're flowing pretty fast, they are interacting with rocks and stuff along the way, but they don't have a lot of time.
• 19:42
  SPEAKER_01: The water-rock interaction takes a long time.
• 19:44
  SPEAKER_01: The other thing about groundwater is surface area.
• 19:46
  SPEAKER_01: If you have water percolating through soil or rock, there's so much more surface area.
• 19:52
  SPEAKER_01: You have water kind of trickling through cracks and working its way through and kind of percolating through this rock system, there's a lot more rock exposed to the same volume of water than there is in a stream.
• 20:03
  SPEAKER_01: So surface area time makes this reaction, this weathering reaction, go faster.
• 20:08
  SPEAKER_00: And certain rocks tend to be much more susceptible to this kind of dissolution than others.
• 20:14
  SPEAKER_00: And if you've ever been inside of a cave that involves the rock limestone, and limestone is just the one that calcium carbonate is very susceptible to being dissolved even in a very weak acid solution like a carbonic acid.
• 20:27
  SPEAKER_01: Yeah, absolutely.
• 20:28
  SPEAKER_01: So we have groundwater, and as you said, groundwater feeds streams.
• 20:32
  SPEAKER_01: If you have uh what's called a freestone stream where it's basically fed by rain or runoff water that's flowing along the surface, that won't be that salty, that won't have that much hard water in it because it's like rainwater coming, it's being in snow, snow melt, draining off, and going right into the river.
• 20:48
  SPEAKER_01: If you have like a spring creek, something that's fed by springs, like we have here in Pennsylvania, that water is pretty salty, pretty quote unquote hard, because it's fed mostly by groundwater.
• 20:57
  SPEAKER_01: And groundwater has all that time and all that surface area to drive that chemical reaction forward.
• 21:02
  SPEAKER_01: So groundwater goes into streams, streams become salty.
• 21:06
  SPEAKER_00: But not really salty.
• 21:07
  SPEAKER_00: They get their salts from it, right?
• 21:09
  SPEAKER_00: When you say that to a group of young people, they're gonna think, oh, it's gonna taste salty, but they know that it doesn't, you know, and and so we're talking about then the rivers are dumping bit by bit by bit salts into the ocean.
• 21:23
  SPEAKER_00: The only way that water leaves is by evaporation, and then the salts stay.
• 21:28
  SPEAKER_00: So over geologic time, these salts are gonna accumulate, right?
• 21:32
  SPEAKER_00: It's kind of to me, it's a little bit like distillation, if that makes sense.
• 21:37
  SPEAKER_00: You're just separating the water from the salts in the oceans.
• 21:41
  SPEAKER_00: This process, that's what happens.
• 21:43
  SPEAKER_00: That's the only way the water's gonna leave.
• 21:45
  SPEAKER_01: Yeah, that's exactly right.
• 21:46
  SPEAKER_01: And so, you know, the key here is that different reservoirs have different salt concentrations and rivers, they are salty, but not very much, not enough to taste.
• 21:54
  SPEAKER_01: That's even your hard water, Chris.
• 21:56
  SPEAKER_01: You're pumping water out of the ground from your well, it's hard, but it doesn't.
• 22:00
  SPEAKER_01: Taste like salt.
• 22:00
  SPEAKER_01: I mean, maybe you can taste a difference between like the water coming out of the city water system, but it's not like you're tasting salt water, right?
• 22:08
  SPEAKER_01: It's not even close to the ocean level.
• 22:10
  SPEAKER_01: So it has some salt in it, but not very much.
• 22:12
  SPEAKER_01: And then the salt gets driven up in the oceans because of time and evaporation.
• 22:17
  SPEAKER_01: And that's the same thing as like restricted basins.
• 22:19
  SPEAKER_01: The Great Salt Lake in the western US, there's a whole bunch of these sort of salt deposits, actual salts that are deposited from these lakes that are restricted basins, where evaporation is the main way that water gets out of this lake.
• 22:33
  SPEAKER_01: That just drives up the salt content in the same way that it happens in the oceans.
• 22:37
  SPEAKER_01: It's just doesn't have as much time.
• 22:38
  SPEAKER_01: So anyway, that's a little bit of a side tangent.
• 22:41
  SPEAKER_00: But and bringing this back then to people that have well water, typically are gonna have to have a water softener to take these salts out of the water.
• 22:49
  SPEAKER_00: If you don't, or you don't keep up on your water softener, which that means dumping salt in your water softener, which it seems counterintuitive, but then you can have problems that are created by this, then like you can get then lime precipitated on the inside of pipes and it especially happens, Chris, in your hot water pipes because that water's hotter and so you know it's starting to precipitate stuff more.
• 23:11
  SPEAKER_01: I often see this, Chris, on like my coffee kettle, and we have like a hot water kettle as well.
• 23:16
  SPEAKER_01: And if you run that hot water, you know, heat up the hot water kettle for a little a couple times, you can see the the sort of white precipitate stuff that's in there.
• 23:23
  SPEAKER_01: And that stuff's actually pretty hard to dissolve.
• 23:25
  SPEAKER_01: You've got to like dump vinegar in it to clean it out to actually dissolve that stuff because it's really hard to re-dissolve.
• 23:30
  SPEAKER_01: Yeah, exactly.
• 23:31
  SPEAKER_01: That's exactly right.
• 23:32
  SPEAKER_01: It's rock, so it can cause problems.
• 23:35
  SPEAKER_01: Um, and we also you can figure out how hard your water is, right?
• 23:38
  SPEAKER_01: How hard your water supply is.
• 23:40
  SPEAKER_00: Oh yeah, super interesting, Jesse.
• 23:42
  SPEAKER_00: I have a little side note here.
• 23:43
  SPEAKER_00: Um, you can see that you know, parts of Michigan have hard water, they're deep red in here.
• 23:49
  SPEAKER_00: Virginia, though, where my son and bonus daughter live, they don't.
• 23:53
  SPEAKER_00: They have a well, but they don't need a water softener, which is super interesting.
• 23:58
  SPEAKER_00: And she was asking me about this, my bonus daughter, she's like, you know, when I wash my hands or something like that, I use soap, it feels really, really slippery.
• 24:07
  SPEAKER_00: Oh, yeah.
• 24:08
  SPEAKER_00: Interesting.
• 24:09
  SPEAKER_00: That is a telltale sign of soft water, right?
• 24:12
  SPEAKER_00: I don't notice it anymore because I've had well water in a water softener for most of my life.
• 24:16
  SPEAKER_00: So I don't notice it anymore, but it's a it is a thing that you feel like it's just softened water.
• 24:23
  SPEAKER_00: The soap does a really good job and it leaves this kind of you have this slippery kind of feeling on your skin.
• 24:29
  SPEAKER_00: It's I don't know, it's hard to describe.
• 24:30
  SPEAKER_00: Do you know what I'm talking about?
• 24:31
  SPEAKER_01: Yeah, yeah, no, for sure, for sure.
• 24:33
  SPEAKER_01: I definitely know what you're talking about.
• 24:34
  SPEAKER_01: You know, I always I always liked the well water.
• 24:37
  SPEAKER_01: Um, it's a like a different taste, right?
• 24:39
  SPEAKER_01: You know, it's slightly different taste.
• 24:40
  SPEAKER_01: Not like going over to the bullheist household and have some well water because it has a a little bit different taste.
• 24:45
  SPEAKER_01: It doesn't taste chemical, it just kind of tastes like I'm getting some nutrients here in this water.
• 24:49
  SPEAKER_00: Yeah, do you do you notice a little funk to it or not?
• 24:53
  SPEAKER_00: Your water in particular?
• 24:54
  SPEAKER_00: Maybe natural gas?
• 24:55
  SPEAKER_00: Yeah, my water.
• 24:56
  SPEAKER_01: Yeah, no, I not that I remember.
• 24:57
  SPEAKER_01: I remember last time or a couple times ago that I was over there, you you mentioning it, and it didn't stand out to me necessarily.
• 25:04
  SPEAKER_00: Some people are very sensitive to that.
• 25:05
  SPEAKER_00: I I'm not, but so anyway, we bought a new refrigerator and um I put a filter in that in line with it.
• 25:11
  SPEAKER_00: And so that water now is I love it.
• 25:15
  SPEAKER_00: It's so good.
• 25:16
  SPEAKER_00: There's no there's no funk to it or anything like that.
• 25:18
  SPEAKER_00: It's just ah, I love well water.
• 25:20
  SPEAKER_00: Yeah, I mean, you you get a little bit of salt, you get some nutrients, you know.
• 25:24
  SPEAKER_01: Yeah, no, that's exactly right.
• 25:25
  SPEAKER_01: And even uh here in Pennsylvania, we have city water, but the city water is pretty hard.
• 25:29
  SPEAKER_01: I mean, we don't need to treat it, but it is on the hard side.
• 25:32
  SPEAKER_01: Some people do have water softeners just to soften it up because they don't like the hard water or something.
• 25:37
  SPEAKER_01: I mean, we get a lot of like scaly deposits in, like I said, the coffee maker just gotta like run vinegar through it every once in a while to are you talking about both places, like in York or and state college, or more so in state college.
• 25:50
  SPEAKER_01: It's a big limestone.
• 25:51
  SPEAKER_01: I mean, in the eastern Pennsylvania here, we're in the Piedmont, so we're like much more like Virginia.
• 25:54
  SPEAKER_01: You know, we're kind of in basement rocks here, not a lot of limestone anymore.
• 25:58
  SPEAKER_01: So interesting.
• 25:59
  SPEAKER_01: You know, once again, Chris, it's all controlled by geology.
• 26:02
  SPEAKER_01: The geology kind of runs everything, it runs this.
• 26:06
  SPEAKER_00: Makes the world go round.
• 26:07
  SPEAKER_00: I know, I know.
• 26:08
  SPEAKER_00: It's so good.
• 26:09
  SPEAKER_00: Let's bring this back, Jesse, as we wrap up this episode.
• 26:12
  SPEAKER_00: Listen, we're talking about climate.
• 26:14
  SPEAKER_00: This is you know, number four in our series on climate, but it's important to talk about salty oceans, hard water in this discussion.
• 26:22
  SPEAKER_00: Absolutely.
• 26:22
  SPEAKER_00: Because this weathering, this chemical weathering process that brings these salts calcium, carbon, oxygen, hydrogen, that brings them to the oceans, and then those ions recombine and get put into the slow carbon cycle.
• 26:39
  SPEAKER_00: And so that's that it it I think it comes full circle.
• 26:42
  SPEAKER_00: Like, it does, it absolutely does.
• 26:44
  SPEAKER_01: And like I said at the outset, I have a hard time with this because it's just it's one of those things where it's so important.
• 26:51
  SPEAKER_01: It it is once you grasp this, once you understand how this works, it is so beautiful.
• 26:56
  SPEAKER_01: It just links so many parts of our lives, right?
• 26:58
  SPEAKER_01: If you have hard water in your home, you can turn on your faucet, and every time you see that little white residue in your coffee pot, you can say, Oh, this is actually why Earth is habitable.
• 27:09
  SPEAKER_01: Like this thing right here, this is a representation of the reason that Earth is habitable because it's part of this thermostat that regulates Earth's climate, makes it warmer than it should be compared to other planets without this whole salty water, uh groundwater weathering cycle.
• 27:25
  SPEAKER_01: It's just a beautiful thing.
• 27:27
  SPEAKER_01: Understanding that link allows you to kind of recognize that every day and appreciate that every day.
• 27:34
  SPEAKER_01: Hey, the more you know, right?
• 27:35
  SPEAKER_01: The more you know, the more you know.
• 27:37
  SPEAKER_01: Hey, well, uh I'm excited to come back to the bullheads household and have some uh have some good well water.
• 27:43
  SPEAKER_01: Anytime.
• 27:43
  SPEAKER_01: Anytime.
• 27:44
  SPEAKER_01: Do you do uh random question?
• 27:45
  SPEAKER_01: Do you know what the aquifer is?
• 27:47
  SPEAKER_01: Is it a sandstone or is it like a a sandy layer?
• 27:50
  SPEAKER_01: And how deep is the aquifer?
• 27:51
  SPEAKER_01: Do you know?
• 27:52
  SPEAKER_00: So, yeah, my well is 124 feet deep.
• 27:55
  SPEAKER_00: Okay.
• 27:56
  SPEAKER_00: And it's a glacial aquifer.
• 27:58
  SPEAKER_01: Okay, gotcha.
• 27:59
  SPEAKER_01: So it's like a a sandy layer or something like that.
• 28:01
  SPEAKER_01: Yes, yes, okay.
• 28:02
  SPEAKER_01: Exactly.
• 28:03
  SPEAKER_01: Interesting.
• 28:03
  SPEAKER_01: Oh, cool.
• 28:04
  SPEAKER_01: That's super cool.
• 28:05
  SPEAKER_01: I mean, uh uh kind of an amazing, uh, I don't know, amazing thing.
• 28:08
  SPEAKER_01: It's very, very cool and fun to think about.
• 28:11
  SPEAKER_01: Well, uh, Chris, I don't know.
• 28:12
  SPEAKER_01: What do you think?
• 28:12
  SPEAKER_01: That's a wrap for oceans.
• 28:14
  SPEAKER_01: And just remember, why are oceans salty?
• 28:17
  SPEAKER_01: Well, that's all right.
• 28:18
  SPEAKER_01: That's a good thing to ponder.
• 28:20
  SPEAKER_01: Hey, that's a wrap for this episode.
• 28:22
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• 28:23
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• 28:52
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• 28:53
  SPEAKER_01: Peace.