How can a lake explode?


Announcer: Welcome to Stuff You Should Know from HowStuffWorks.com.

Josh Clark: Hey, and welcome to the podcast. I'm Josh Clark. Chuck Bryant is with me. Hey, Chuck.

Chuck Bryant: Hi, Josh.

Josh Clark: How you doing?

Chuck Bryant: I am recovering from kids day.

Josh Clark: Yeah, Chuck and I - actually, I didn't volunteer. Chuck volunteered himself and me to wrangle kids for kids day. I gotta tell you, the adult to kid ratio was one and a half to one, and I'm still wiped.

Chuck Bryant: There were literally like four kids, and what, like eight of us, eight adults.

Josh Clark: No, six.

Chuck Bryant: Six. And I was worn out, man.

Josh Clark: Yeah, kids day is just awesome, 2009.

Chuck Bryant: Yea, the energy - actually, my favorite part of the day was when we brought them on the tour and brought them into the studio, and Jerry looked like she was about to crawl out of her skin.

Josh Clark: Yeah, our producer, Jerry, does not like kids, it turns out.

Chuck Bryant: That was awesome. She put on a real sweet face and was smiling, going, "Hi, everybody." And then the kids got in the sound booth and screamed to see if we could hear them.

Josh Clark: And we could. Kids are fun. Especially 12 year olds!

Chuck Bryant: They're great.

Josh Clark: So I'm glad it's over.

Chuck Bryant: Yes.

Josh Clark: I actually got tapped to do it again next year. Did you?

Chuck Bryant: No, I just kind of figured we did such a bang up job that they'd want us back.

Josh Clark: Well anyway, thanks for that, Chuck.

Chuck Bryant: You were a natural.

Josh Clark: I owe you big time. Let's talk about exploding lakes then.

Chuck Bryant: Okay, sure.

Josh Clark: Chuck, have you ever seen a 328-foot tall cloud of death?

Chuck Bryant: There's a bathroom joke in there somewhere that my wife would appreciate, but the straight answer is no.

Josh Clark: Your wife like scatological humor?

Chuck Bryant: Yeah.

Josh Clark: I didn't know that. I wouldn't have pegged her for that.

Chuck Bryant: She's dirty.

Josh Clark: She seems way too intelligent for that kind of thing.

Chuck Bryant: She is, but that means nothing. She's still scattin' the logical -

Josh Clark: Well, you know, had you lived around a little lake called Lake Nyos in August of 1986, you would have seen a 328-foot tall cloud of death. And had you walked in it, you probably would have died.

Chuck Bryant: Right. It was frightening, I bet.

Josh Clark: It was. Chuck sent me this great picture that - you think we could post that on our blog when this comes out?

Chuck Bryant: You keep saying that.

Josh Clark: Did we do that last time?

Chuck Bryant: Actually, that would have been today with the face transplant and I did not get the rights to that.

Josh Clark: Did you try to get the rights?

Chuck Bryant: I did. I looked into it.

Josh Clark: You're such a liar. Okay, well, Chuck sent me this great picture of all these dead cows just kind of fallen over on their sides around the lake in 1986. Basically, what happened was on, I think, the evening of August 21st, all the sudden, there was this rumbling sound. And Lake Nyos is a pretty substantial lake. I think it's over 600 feet deep.

Chuck Bryant: Yeah, this is in Africa. We haven't even said that.

Josh Clark: I'm sorry. Yeah, it's in Cameroon. And there was this rumbling from within the lake. And all of a sudden, this huge column of water shoots out of the middle of the lake, hundreds of feet into the air, and as this column is going, this cloud that eventually becomes a 100-meter cloud starts to develop. But the thing is it's kind of hovering close to the lake. So it's a really heavy cloud. Then this cloud gets the bright idea of moving off of the lake and down into the populated valley.

Chuck Bryant: Right, which is, I guess, just where the airflow took it.

Josh Clark: I guess, and it clung very low to the ground. It sunk, basically. It just followed the ground into valley. And so you think, "Hey, there's a cloud. What harm can a cloud do?" But the people who took that attitude paid with their lives to the tune of 1,700 of them. Right?

Chuck Bryant: Yeah.

Josh Clark: People up to 15 miles away from the lake died.

Chuck Bryant: Livestock.

Josh Clark: Livestock, people. Some people were knocked unconscious. It depended on the concentration of the secret ingredient we'll get to in a second. Some people were unconscious for like 36 hours. They wake up, and all their livestock and their family is dead.

Chuck Bryant: I know. Unbelievable!

Josh Clark: I mean imagine this. Really put yourself into that situation. You're hanging around; you're living your life of an idyllic agrarian life around this beautiful lake, which supposedly used to be this gorgeous blue.

Chuck Bryant: It was. It was really, really pretty.

Josh Clark: And all of a sudden, the lake blows up, and there's a cloud of death that kills your entire family and knocks you out for a day and a half.

Chuck Bryant: Well, and the lake turned - did you see the after photos? It turned really brown, and the water level lowered, and it was disgusting. It looked like a before/after photo of like 100 years of pollution or something.

Josh Clark: Wow. And this was overnight.

Chuck Bryant: Yeah.

Josh Clark: So finally, after about two days, this cloud dissipates, but not before it moves through village after village just killing people. And so obviously, when people start to come in to investigate what happened, they find all of these dead bodies. The government got involved, and rightfully so.

Chuck Bryant: Sounds like an X-Files episode.

Josh Clark: Definitely. That's exactly what it sounds like.

Chuck Bryant: But it was real.

Josh Clark: Yeah, well, X-Files is real, too.

Chuck Bryant: Really?

Josh Clark: Sure. Based on real accounts as far as I know! Every single one.

Chuck Bryant: Did not know that.

Josh Clark: Yeah. So yeah, the government gets involved, which means science gets involved because being an elected official doesn't necessarily make you a science-y type. You're not an egghead. Right?

Chuck Bryant: Far from it.

Josh Clark: Right. So the Cameroonian government recruited some scientists to say, "What the hell just happened?" There's 1,700 people that were killed by a cloud of death. What just happened? Chuck, what happened in August of 1986 at Lake Nyos, Cameroon?

Chuck Bryant: Well, Josh, the secret ingredient, I know you know the answer, was CO2. Carbon dioxide! Pretty simple.

Josh Clark: But where did it come from, Chuck? Stop being coy with me!

Chuck Bryant: That's the thing is they quickly realized it was CO2. That wasn't the hard part. Figuring out actually how this cloud came up from the lake was the hard part. And there were a couple of theories at the time. One was that an underwater volcano had erupted and pushed this gas up, which sounded pretty plausible to me. And I actually looked at some of the old articles. And that's kind of what they said it was for a while.

Josh Clark: Right, well, there was a split camp. Right?

Chuck Bryant: Yeah.

Josh Clark: The problem is they went through and set up - The British Geological Survey set up some seismographs around the lake, and there should have been some small aftershock earthquakes, and they measured nothing.

Chuck Bryant: Nada.

Josh Clark: They also didn't find any sudden sulfur levels that would have been residual from a volcano explosion. Right?

Chuck Bryant: Right.

Josh Clark: So that one kind of got scrapped, and they went with the other camp, which was -

Chuck Bryant: Which was a gigantic, deadly burp, basically, is how it's described in the article, which is exactly what it was. So I guess we need to go back in time when Lake Nyos formed to really understand this. Right?

Josh Clark: We need our back in time music. Okay. So 1986, Chuck. Ghostbusters is sweeping the nation. Right?

Chuck Bryant: Well, no, we need to go back to when Lake Nyos was formed. It wasn't in 1986.

Josh Clark: Oh, we have to go even further back. Here is our time travel music again. So Chuck, what year are we in? This place doesn't look very heavily populated.

Chuck Bryant: Well, it's a long, long time ago.

Josh Clark: We're talking, what, thousands of years before Ghostbusters.

Chuck Bryant: Yeah, seven or 8,000 years maybe. And that's a guestimation. So if someone from Cameroon writes in and says it was actually 9,000 years, give Chuckers a break on this one. It's a long time ago. So Josh, Cameroon and Africa, there's a lot of weak spots in the crust around that area. Do you know what magma is?

Josh Clark: I do. It's molten lava that hasn't reached the earth's surface yet.

Chuck Bryant: Exactly. So it's like liquid rock, and -

Josh Clark: That's another way to put it.

Chuck Bryant: It rises from the earth's mantle and shoots up quickly and vertically, and it cuts a tube towards the surface. And when it reaches the surface, the magma can rain down a big pile of rock.

Josh Clark: To form a cinder cone volcano. Right?

Chuck Bryant: Absolutely. You're with me.

Josh Clark: Or - can I say the other part because it's cool?

Chuck Bryant: Yeah.

Josh Clark: Or if this magma, which is shooting up out of the ground, comes in contact with wet rock, an explosion happens, huge explosion, and this is what formed Lake Nyos.

Chuck Bryant: It formed a big crater.

Josh Clark: It just went kaboom, and all of a sudden, there's a crater. And then this crater started to fill in over the years, and now it's a volcanic crater lake.

Chuck Bryant: Yeah, take a crater, add water, and you have a lake.

Josh Clark: Yeah, Lake Nyos.

Chuck Bryant: And a very pretty one at that. So basically, that's what happened. You've got at the bottom of the lake, you have an old tube where the magma rose up, and to the surface, and it remains there. So if you go down about six miles, you'll hit the magma.

Josh Clark: Right, it's staying down there.

Chuck Bryant: Yes.

Josh Clark: But there's still CO2 coming up through this column.

Chuck Bryant: Right, but it stays trapped because of the fact that Lake Nyos was 600 and some odd feet deep.

Josh Clark: Right. Every 33 feet there's one atmosphere of pressure, and so this is about 20 atmospheres, which is dense and heavy enough to keep a bubble of gas held down at the bottom.

Chuck Bryant: Right.

Josh Clark: The problem is gas builds up in every kind of lake there is. Right?

Chuck Bryant: Right.

Josh Clark: Every lake, every pond.

Chuck Bryant: I didn't know this. This was interesting.

Josh Clark: I didn't either, but I'm going to pretend like I did. Watch me go. You know, when like leaves and other organic matter - dead fishes fall to the bottom, they produce gas, CO2, maybe methane, that kind of thing. And this happens in any body of water. But the thing is in most climates, in temporary climates, there's an actual gas exchange that happens annually. When the temperatures cool, the surface water cools and goes to the bottom, which displaces the gas, and it happens very calmly and casually. There you go. There's no explosion.

Chuck Bryant: Interesting.

Josh Clark: The problem with Lake Nyos and other lakes in Cameroon is that there isn't a seasonal change. It's warm all the time.

Chuck Bryant: Exactly, so it just stays that way.

Josh Clark: There's never that turn over, and this bubble of gas that's coming up from the magma shaft gets bigger and bigger and bigger and bigger.

Chuck Bryant: I think magma shaft would be a good pseudonym for you.

Josh Clark: That is a good pseudonym.

Chuck Bryant: Magma shaft.

Josh Clark: Yeah, magma shaft. That's nice.

Chuck Bryant: So yeah, basically, it acts like a champagne cork, all this water sitting on top of it. And in order - actually, we kind of left out the part at the beginning that something needs to happen to trigger the gas to be released. It's not gonna just happen on its own. And they think it may have been like a rock slide.

Josh Clark: Right, or an earthquake.

Chuck Bryant: Sure.

Josh Clark: And usually, what happens is the whole bubble doesn't get displaced or the whole layer of gas doesn't get displaced. Part of it will, but since its one big cohesive layer, one part of it being ripped off will dislodge the rest of it. Then all of a sudden, you've got a huge column of water coming up.

Chuck Bryant: Unbelievable.

Josh Clark: Gas, CO2 going everywhere, forming a cloud of death, bada boom, bada bing, 1,700 villagers and countless livestock dead.

Chuck Bryant: Yeah, and this happened a couple of other times in Africa. There's two other lakes. Right?

Josh Clark: Cameroon is lousy with exploding lakes.

Chuck Bryant: I know. Well, it's because of where it's situated.

Josh Clark: Yes, that is true, Chuck. It's situated over a very thin part of the earth's crust, as you said. Right?

Chuck Bryant: Right, and there's two more lakes. Lake Monoun and Lake Kivu! Both of those have had incidents as well, but not nearly as deadly.

Josh Clark: Lake Kivu hasn't happened yet.

Chuck Bryant: Oh, it hasn't?

Josh Clark: Lake Kivu is between Rwanda and Congo, and that one, if it does happen, would be an amazingly catastrophic natural disaster. It's twice as deep as Lake Nyos, which again, remember, killed 1,700 people from the cloud it produced. So this one is twice as deep, and there's about two million people living around it! So they would be in really big trouble if Lake Kivu all the sudden erupted, and it most likely will. They've been studying it, and apparently, it's right there about to happen. Nobody is doing anything about it.

Chuck Bryant: Really?

Josh Clark: Yeah, they just finally got around to doing something about Lake Nyos. You want to talk about that?

Chuck Bryant: Yeah, that's a great segue, actually, Josh. You're a natural.

Josh Clark: Thanks.

Chuck Bryant: You've been doing this a year. We had our one year anniversary, by the way. No one even recognized that.

Josh Clark: No, I didn't even know. When?

Chuck Bryant: Yeah, we had a fan come in, and we had our 100th episode.

Josh Clark: A fan came into the office?

Chuck Bryant: Yeah.

Josh Clark: No.

Chuck Bryant: No, a fan wrote in and said that it was our one year anniversary, and we also had our 100th episode, which you -

Josh Clark: I remember the 100th episode. One year anniversary! Wow. Happy anniversary, beautiful!

Chuck Bryant: You, too. You, too, Jerry!

Josh Clark: Yeah, happy anniversary, Jer.

Chuck Bryant: So enough of that. Yes, what they basically came up with a really basic - some of the coolest ideas in science to me are so simple. Like you would have thought a kid came up with this idea.

Josh Clark: Like the space shuttle.

Chuck Bryant: Exactly. They make a big plane that goes into space. They decided to degas it with a big straw.

Josh Clark: Yeah, they just basically put a big pipe into the bubble, and all of a sudden, a bunch of CO2 water came up.

Chuck Bryant: And they degas it a couple times a year. I'm sorry, couple times a day, I think. And there's a webcam. Have you seen the webcam?

Josh Clark: No, but I saw a picture of it. It looks like one of those lakes that a country club subdivision -

Chuck Bryant: The cheesy fountain in the middle.

Josh Clark: Exactly. That's exactly what it looks like. I didn't know there was a webcam. Do you know the address URL?

Chuck Bryant: I don't know off the top of my head.

Josh Clark: So what do you type in? Lake Nyos webcam!

Chuck Bryant: Degassing webcam. You can probably find it. But before you go there, you should know that the last image is from November of last year, so it looks like it may not be actively running anymore. Because I think the whole idea of a webcam is to show things like as it happens.

Josh Clark: I think so, too. Yeah. Not from November of last year.

Chuck Bryant: So that's basically what they did. They put the first pipe in in 2001. A French engineering team!

Josh Clark: But the sad thing is these foreign scientists who came to Nyos to figure out what happened said pretty quickly, "This is what we should do. We should pop a straw in that CO2 layer."

Chuck Bryant: In 1986.

Josh Clark: In 1986. In 2001, the first pipe went in. But I read that they were hoping to have the CO2 levels down 99 percent by next year.

Chuck Bryant: Really?

Josh Clark: That's what I read.

Chuck Bryant: That's awesome.

Josh Clark: We'll see what happens.

Chuck Bryant: Well, and I think it looks a little bit better than it used to as well.

Josh Clark: It's pretty again?

Chuck Bryant: I don't think it's back to where it was pre-1986 when it was a really cool looking lake, but I don't think it's the brown mess that it was right afterward, either, with cows floating in it and stuff.

Josh Clark: So do you want to hear something interesting?

Chuck Bryant: Always.

Josh Clark: First of all, these kind of exploding lakes are actually called limnic eruptions. That's the scientific word for it, and we understand the explanation. But the people in Cameroon who lived around Lake Nyos had another story for it. And basically, the gist of it is that every once in a while, evil spirits rose from the lake and killed people in villages. I'm not entirely certain why. Probably because they were evil spirits! Right?

Chuck Bryant: Right.

Josh Clark: But you know what that's called?

Chuck Bryant: What?

Josh Clark: That's called a euhemerism.

Chuck Bryant: Really? When something is explained in a different, mystical way!

Josh Clark: When a myth is clearly based on historical occurrences. So they're saying that these exploding lakes that happened before and in the past while people were still living around pre-science, though. So they explained it with evil spirits emerging from the lake, but pretty much with the same result. Cloud of death, that CO2 cloud of death made of evil spirits. In the end, you're still dead, and so is your livestock.

Chuck Bryant: Can you imagine being - as man evolved and started to figure things out when they first started thinking and saw a volcano what that must have - I mean they probably thought the same thing that someone was trying to kill them with hot, molten lava.

Josh Clark: Yeah, they always pegged it on evil spirits. Didn't they?

Chuck Bryant: Yeah.

Josh Clark: And now, once science is around, they're like, "God, is my face red?"

Chuck Bryant: I know. But there's no secret anymore. It's kind of disappointing.

Josh Clark: There's still plenty. Like, "Do you know how the space shuttle works?" No.

Chuck Bryant: Well, I could go read about it. Figure it out.

Josh Clark: I guess you could. So Chuck, yeah, we've got Lake Nyos, it seems, under control. Lake Kivu is still a problem.

Chuck Bryant: So they haven't stuck the straw in that one yet.

Josh Clark: Not as far as I know. Then there's one in Ecuador. Lake Quilotoa! And that one is about if it erupted, it would be on the level of - or degree of Nyos. So there's exploding lakes just waiting for a limnic eruption all around the world. So if you live in the tropics and you're a lake, move.

Chuck Bryant: Is that your advice?

Josh Clark: That's my advice. Yeah. So what do you think? Is it done? Did we do it?

Chuck Bryant: I think we covered everything.

Josh Clark: You feeling pretty good?

Chuck Bryant: Yeah.

Josh Clark: Are we plugging things any longer? Let's do the blog.

Chuck Bryant: Plug the blog?

Josh Clark: Plug it.

Chuck Bryant: I like the plug from the one on the face transplant, the Hulk one. Blog good, Chuck Josh write blog.

Josh Clark: Fire bad.

Chuck Bryant: Fire bad. Should we just redo that one?

Josh Clark: Sure, go ahead.

Chuck Bryant: Or did we just do that?

Josh Clark: Should we just reuse the one that we recorded before? No. Jerry is saying no. So start fresh, Chuck.

Chuck Bryant: So Josh, we have a blog. We've been plugging this like - I'm trying to think of a plug analogy, but I can't think of any. We've been plugging this for a while. It's on the right side of the homepage is where you can get it.

Josh Clark: Right rail.

Chuck Bryant: It's called Stuff You Should Know.

Josh Clark: In tech speak.

Chuck Bryant: In tech speak. And we've gotten a lot of fans interacting now, which is cool. And I'd also like to point out that the blog is now where you can go just for a little news. Josh and I are kind of venturing out into these little opportunities now being interviewed on ABC News, by the way.

Josh Clark: Being tickled by strangers for money.

Chuck Bryant: Right. Little things like that are starting to pop up here and there, so the blog is where we'll promote that and let people know where they can support us and that kind of thing.

Josh Clark: Yeah, I gotta tell you, Chuck, I'm very grateful for some of my friends, like my friend SG, actually, is much smarter than me and knows all sort of stuff that I get fed that makes me look smart because I just go ahead and post on it.

Chuck Bryant: Oh, is this one of the blog commenters?

Josh Clark: Yes, yeah.

Chuck Bryant: Nice. Smart people!

Josh Clark: So I'd be lost without my - smart people, yeah. I'd be lost without them.

Chuck Bryant: That was heartfelt.

Josh Clark: Thanks, Chuck.

Chuck Bryant: I rarely see that out of you.

Josh Clark: I know. I'm usually just so dark and ang ry and evil.

Chuck Bryant: Like a Sith lord.

Josh Clark: Kind of, except without the red face point. So I guess that's plug in.

Chuck Bryant: Yeah, that's the plug fest.

Josh Clark: You guys have been plugged, and now, it's time for listener mail.

Chuck Bryant: So Josh, we just have one under the banner of exceptional listener mail.

Josh Clark: That is a long one, Chuck. Are you going to read that whole thing?

Chuck Bryant: No, I'm going to do my scan thing. This comes to us from Helen in Guatemala. Specifically in Quetzaltenango, Guatemala! And she's writing in about the 2012 episode. She lives in the western highlands, and there are still Mayan people there, lots of them. And she has been fascinated to hear so much about this 2012 stuff, but only from US media outlets. Apparently, none of the Mayans are talking about it. No one cares about it.

Josh Clark: I got that impression, too, when I was researching. I think we even mentioned that that yeah, it's very much western.

Chuck Bryant: Yeah, very much. She said, "Our own calendar begins every week, month, year, etc. The Mayan calendars all function in a circular rather than linear concept of time and form cycles that repeat infinitely." So they don't think the world is going to end at any particular point on the calendar. The repeating cycles are based on the idea of keeping count of the passage of time, which is very important in the culture. So she did want to compliment us that we've come closest to just completely debunking this than most US media outlets.

Josh Clark: Don't tell that to the Belgians, though.

Chuck Bryant: Right. She did want to point out; however, that I believe at one point, one of us said something about the Mayan calendars are used in secret. She said that's not really true. You can get them in bookstores all over the place there, and they are used, and different calendars have different uses, which I thought was interesting. There's three major ones. An everyday calendar for planning everyday stuff, fittingly, a religious calendar for planning rights and ceremonies, and an agricultural calendar for planning planting and harvesting. And they still use these. You can get books on how to use them, and it sounds like really a kind of interesting thing.

Josh Clark: I could see that daily calendar, you know, them selling it. Things to do today if you're Mayan!

Chuck Bryant: Right. Stock up on canned goods.

Josh Clark: In case world ends in 2012.

Chuck Bryant: So Helen thanked us, and she's in Guatemala, and she's a cool lady.

Josh Clark: Thanks, Helen. We appreciate it. If you live in Guatemala, Guam, or anywhere else and you want to send Chuck or me an e-mail, send it to StuffPodcast@HowStuffWorks.com.

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