WEBVTT - How Landslides Work 0:00:01.120 --> 0:00:04.280 Welcome to you stuff you should know from House Stuff 0:00:04.280 --> 0:00:12.640 Works dot com. Hey, and welcome to the podcast. I'm 0:00:12.720 --> 0:00:15.600 Josh Clark and Charles W. Chuck Bryant is with me 0:00:15.640 --> 0:00:19.280 as always. Hello, sir, Hello, how are you. I'm good 0:00:19.079 --> 0:00:22.160 with that Jerry in the house. Oh yeah, that's when, uh, 0:00:22.840 --> 0:00:28.080 you know, I probably won't be our funniest podcast. And 0:00:28.120 --> 0:00:32.800 I have to say that I suggested landslides without knowing 0:00:32.840 --> 0:00:37.239 about that landslide. No, I swear, no, I promise you. 0:00:37.280 --> 0:00:40.080 I sent this to you on Monday, and then I 0:00:40.120 --> 0:00:43.960 saw like a few hours later, Wow, and it was like, 0:00:44.000 --> 0:00:46.360 oh boy, I didn't you know. I was. I was 0:00:46.400 --> 0:00:50.160 on vacation, so I didn't hear about it. Um, but yeah, 0:00:50.400 --> 0:00:53.040 so it's super relevant. Well yeah it is, you know, 0:00:53.200 --> 0:00:57.240 apparently unintentionally relevant like our Black Boxes episode. Yeah, it's 0:00:57.400 --> 0:01:02.720 been happening weirdly. But yeah, if you have been uh 0:01:02.960 --> 0:01:06.039 not paying attention to the news at all lately, then 0:01:06.080 --> 0:01:09.000 you may not know. But there was a massive landslide 0:01:09.000 --> 0:01:12.880 in Washington as of last count I think, um, the 0:01:13.000 --> 0:01:16.880 death tolls at like twenty four, which is an astoundingly 0:01:16.959 --> 0:01:20.480 high number for a landslide. Uh, at least in the 0:01:20.520 --> 0:01:24.040 United States because something like twenty five to thirty five 0:01:24.120 --> 0:01:28.160 people die in the US a year from landslides. This 0:01:28.200 --> 0:01:32.240 one was one single, enormous landslide, and if you haven't 0:01:32.280 --> 0:01:35.520 seen the pictures to get an idea of just how 0:01:35.640 --> 0:01:40.720 large it was, you should go online immediately, um and 0:01:41.120 --> 0:01:44.920 check it out, because it's it was nuts what happened there. Yeah, 0:01:44.920 --> 0:01:46.760 it's about an hour north of Seattle, and I know 0:01:46.800 --> 0:01:48.360 we have a lot of fans in Seattle, so we're 0:01:48.360 --> 0:01:51.920 obviously thinking about everyone there. But um, it is you know, 0:01:51.960 --> 0:01:54.960 there's still you know, a hundred and seventy plus people missing, 0:01:55.000 --> 0:01:58.400 and it's it's it looks like it will be easily 0:01:58.480 --> 0:02:01.280 the deadliest landslide in US history by the time this 0:02:01.320 --> 0:02:03.240 is all said and done. It seems like it. But 0:02:03.280 --> 0:02:06.560 I'm clearly hoping there's more survivors. But it's just a 0:02:06.680 --> 0:02:09.920 scary man. Oh Yeah, to think about like being trapped 0:02:09.960 --> 0:02:12.720 like that and possibly still alive. It's just like the 0:02:12.720 --> 0:02:15.160 whole thing is upsetting, Yeah, because I mean, if you 0:02:15.240 --> 0:02:18.600 were inside a structure it's now covered with mud, you 0:02:18.720 --> 0:02:22.320 might you know, there's a chance that you are you're 0:02:22.360 --> 0:02:27.280 not buried, the structure around you is buried. Um, So yeah, 0:02:27.440 --> 0:02:32.320 it's it's pretty awful stuff. Um, the to me, what's 0:02:32.320 --> 0:02:35.119 even more awful? And I read an article where a resident, 0:02:35.240 --> 0:02:38.680 unnamed resident was saying like, yeah, we're not mad at 0:02:38.680 --> 0:02:41.800 the authorities, but yeah, apparently they didn't heat a lot 0:02:41.840 --> 0:02:48.800 of UM warnings. This area, the area that was covered 0:02:48.800 --> 0:02:52.880 in landslide was known since the sixties. In the area 0:02:53.040 --> 0:02:57.520 is Slide Hill that the area itself is called the 0:02:57.639 --> 0:03:01.560 Steelhead Landslide. So like, imagine if, um, the street you 0:03:01.600 --> 0:03:06.280 live on is is not an East Lake, but in 0:03:06.680 --> 0:03:10.280 Steelhead Landslide. Landslide is in the name of the area 0:03:10.360 --> 0:03:12.880 that you live. So it wasn't like the biggest surprise. No, 0:03:13.120 --> 0:03:16.080 And there was a report by the U. S. Army 0:03:16.120 --> 0:03:20.920 Corps of Engineers that predicted a UM the potential for 0:03:20.960 --> 0:03:25.120 a large catastrophic failure right there where it happened. And 0:03:25.160 --> 0:03:29.120 that's exactly what happened. The landslide happened. It covered about 0:03:30.280 --> 0:03:36.040 a square mile and ums like fifteen feet deep. Right now, Well, 0:03:36.080 --> 0:03:38.200 you can't tell people where to live though, you know, no, 0:03:38.360 --> 0:03:40.760 you definitely can't. I'm not saying they shouldn't have warned, 0:03:40.800 --> 0:03:43.480 but like, people still live in flood zones and people 0:03:43.640 --> 0:03:46.560 still build their houses on the sides of a hill 0:03:46.600 --> 0:03:49.280 in Malibu And yeah, and I guess if you're warned 0:03:49.320 --> 0:03:51.280 and like you were willing to take that risk and 0:03:51.360 --> 0:03:53.680 you wanted to, then yeah, I don't want to disagree 0:03:53.720 --> 0:03:57.000 with that, but I I don't know if um, I 0:03:57.000 --> 0:04:00.280 don't know if everybody was as aware of the potent tool. 0:04:00.680 --> 0:04:03.240 But apparently there was a landslide in the area as 0:04:03.280 --> 0:04:07.440 recently as two thousands six. Yeah, so apparently this was 0:04:07.480 --> 0:04:10.080 the big one and it was coming a long time 0:04:10.120 --> 0:04:12.720 and that and set off by water in this case, right, Yeah, 0:04:12.760 --> 0:04:15.040 there was word that possibly it was an earthquake, but 0:04:15.120 --> 0:04:17.000 they think no, it was. Um, there was a lot 0:04:17.040 --> 0:04:20.880 of rain that that came before then. And so well, 0:04:20.960 --> 0:04:24.120 let's let's get down to explaining what happened exactly. The 0:04:24.800 --> 0:04:28.520 landslide there is actually technically a mud slide. Um, and 0:04:28.760 --> 0:04:31.720 mud slides, landslides, a bunch of other ones. They're all 0:04:31.760 --> 0:04:35.599 they all fall under something called mass movements. Yeah, and 0:04:35.640 --> 0:04:39.360 that is the umbrella term, and that basically means gravity 0:04:39.400 --> 0:04:42.880 is at work moving something down a slope some kind 0:04:42.880 --> 0:04:45.840 of sediment. Um. It can be a landslide, which can 0:04:46.080 --> 0:04:50.280 is obviously devastating, or it can be super slow over centuries. 0:04:50.960 --> 0:04:54.080 And we'll get into all that in a minute. But um, 0:04:54.120 --> 0:04:56.240 and well we'll get into all the triggers too, But 0:04:56.279 --> 0:05:00.320 I guess we should talk about their categorized depending on 0:05:01.200 --> 0:05:05.200 how fast it's moving, UM, what kind of materials are 0:05:05.200 --> 0:05:09.520 being moved. Um. In every case though, you're talking about 0:05:09.680 --> 0:05:15.560 soil moving off of bedrock, the friction being overcome by gravity. 0:05:15.800 --> 0:05:18.920 That's exactly what a landslide is. And it's like super 0:05:19.000 --> 0:05:22.280 fast erosion on any slope. You have soil over rock 0:05:22.480 --> 0:05:25.520 and it's being held in place by friction. It's kind 0:05:25.520 --> 0:05:27.640 of scary to think about it really is. You know 0:05:27.680 --> 0:05:30.279 it's true, but then when you read it, it's like wow. Yeah. 0:05:30.320 --> 0:05:32.600 I mean like if you've ever like dug a hole 0:05:32.640 --> 0:05:36.640 in the ground, it's not easy. It's not like it's 0:05:36.640 --> 0:05:40.839 not like silt or something like that. It's it's like ground. 0:05:40.880 --> 0:05:44.040 It's hard ground. But you know that stuff is it's 0:05:44.120 --> 0:05:48.520 not fused to the bedrock beneath it's it's there's there's 0:05:48.720 --> 0:05:51.880 a kind of um, there's a friction that's holding it 0:05:51.920 --> 0:05:54.920 in place, and that can that can fail, and that's 0:05:54.960 --> 0:05:57.920 that's what a landslide is exactly like you said, gravity 0:05:58.000 --> 0:06:01.599 overcomes friction. Yeah, and it hand on some very large scales, 0:06:01.920 --> 0:06:05.080 it can on small scales. Um. And then like you said, 0:06:05.120 --> 0:06:09.800 depending on the type of movement, how it moves, what's moved, 0:06:10.120 --> 0:06:13.200 you have different categories of mass movements. Land slides are 0:06:13.240 --> 0:06:16.800 just one of them, or a slide is one category. 0:06:16.839 --> 0:06:22.200 The slides, creeps, slumps, and flows. Yeah, creeps are obviously 0:06:22.240 --> 0:06:25.920 super slow. It can be uh months, years, it can 0:06:25.960 --> 0:06:31.360 be centuries of creep. And that is when the sediment, uh, 0:06:31.520 --> 0:06:34.360 when the friction is is not working, but it's not 0:06:34.440 --> 0:06:37.760 completely destroyed, so there's still some friction. It's just moving 0:06:37.839 --> 0:06:41.440 super slow. And that's usually as a result of a 0:06:41.440 --> 0:06:45.000 lot of freezing and thawing going on to change the 0:06:45.040 --> 0:06:49.160 composition of the soil. Yeah. When the when a freeze 0:06:49.160 --> 0:06:53.719 comes through, the sediment in the soil um is pushed 0:06:53.800 --> 0:06:57.119 upward as it freezes, and when it falls, it falls 0:06:57.160 --> 0:07:00.159 back downward. So what you have, if you look at 0:07:00.000 --> 0:07:03.800 it on a geological time scale, is basically an undulation 0:07:05.000 --> 0:07:08.440 up and down of the soil that is moving downward 0:07:08.520 --> 0:07:11.160 on a slope like millimeters at a time. Right, and 0:07:11.200 --> 0:07:14.560 then uh, the telltale signs though, you can see that 0:07:15.200 --> 0:07:18.440 creep is happening because telephone poles will be kind of 0:07:18.480 --> 0:07:22.320 a skewed trees or something like that. Yeah. You that 0:07:22.400 --> 0:07:26.040 means that you're standing on or looking at a slumping 0:07:26.080 --> 0:07:29.480 slope and you won't see it happening. No, but I 0:07:29.520 --> 0:07:32.200 can see a pretty awesome gift. I can't remember where 0:07:32.320 --> 0:07:35.239 was it time lapse. Yeah, it's the time lapse gift. 0:07:35.880 --> 0:07:37.320 And it wasn't over the course of the year. Is 0:07:37.360 --> 0:07:39.040 over the course of I think several days in San 0:07:39.080 --> 0:07:42.200 Bernardino or whatever. But it's just like whoa there goes. 0:07:42.600 --> 0:07:46.040 It makes you feel unstable. Yeah, like the earth beneath 0:07:46.080 --> 0:07:48.880 your feet. Yeah, well, I mean the the earth is 0:07:49.120 --> 0:07:53.679 a constantly evolving mass, you know, soil is being moved 0:07:53.680 --> 0:07:55.440 from here to there, and there's all sorts of different 0:07:55.440 --> 0:07:58.120 agents of change. But and it moves in different ways. 0:07:58.120 --> 0:08:02.120 It can creep. Um. I think I said a slumping slope. 0:08:02.200 --> 0:08:05.600 That's not true. That was a creeping slope. A slump 0:08:05.720 --> 0:08:09.160 is when you have a big chunk that breaks off 0:08:09.200 --> 0:08:13.640 as a single whole chunk and moves. That's a slump. Yeah, 0:08:13.640 --> 0:08:16.560 and that can be the the actual thing can be 0:08:16.600 --> 0:08:18.800 called a slump too. It can have a couple of 0:08:18.880 --> 0:08:21.560 meanings there for that word, like the big piece can 0:08:21.560 --> 0:08:24.840 be called a slump, or if the movement is the slump, 0:08:24.880 --> 0:08:30.200 if they're not sliding like they used top uh, and 0:08:30.280 --> 0:08:34.280 that is when um basically the base can't support this 0:08:34.440 --> 0:08:37.439 big chunk on top of it. And again it's usually 0:08:37.920 --> 0:08:42.520 due to UH moisture and water is the general cause 0:08:42.559 --> 0:08:45.719 for slumps as well. Yeah, waters, like the primary all 0:08:45.800 --> 0:08:50.480 time leading winning is cause of mass movements because either 0:08:51.400 --> 0:08:55.679 like um in a slump. A good analogy or a 0:08:55.720 --> 0:08:57.960 good example is if you're at the beach and you 0:08:58.040 --> 0:09:01.480 just see like a whole um, whole hunk of wet 0:09:01.520 --> 0:09:04.319 sand cheer off of another hunk of wet sand. Did 0:09:04.360 --> 0:09:08.280 you just witnessed the slump? And actually water can create 0:09:08.320 --> 0:09:12.960 stability for sandy, loamy or clay soil, Like you build 0:09:12.960 --> 0:09:15.880 a sand castle, you want the sand wet exactly up 0:09:15.920 --> 0:09:18.199 to a point when you had too much water becomes 0:09:18.200 --> 0:09:20.360 saturated and then you have a slump or you have 0:09:20.400 --> 0:09:23.640 a slider a flow um and then with other types 0:09:23.640 --> 0:09:28.880 of mass movement, that water can get underneath and interrupt 0:09:28.960 --> 0:09:32.760 the friction between the soil and the bedrock, and that's 0:09:32.760 --> 0:09:34.960 when you have some sort of movement as well. So 0:09:35.080 --> 0:09:38.160 that's creep, and that's slump. And then finally we have flow, 0:09:38.840 --> 0:09:43.000 which is uh just basically a soupy mix of water 0:09:43.160 --> 0:09:47.280 and rock and uh soil and other materials, and it's 0:09:47.320 --> 0:09:50.720 just those are usually the deadliest because they spread further. 0:09:51.120 --> 0:09:53.880 That's like a mud flower and avalanche. They get everywhere, 0:09:54.280 --> 0:09:57.440 they'll like enter into everything. That's not just it's just 0:09:57.520 --> 0:09:59.680 like a bunch of dirt. It's it's like a river, 0:10:00.040 --> 0:10:03.880 a moving a fast moving river of mud and debris. 0:10:04.280 --> 0:10:09.880 And I misspoke earlier. That's um in oh So, Washington, 0:10:10.520 --> 0:10:14.200 that's what that's what that was. That was the mud 0:10:14.240 --> 0:10:17.840 flow that started it, that came down and covered everything, 0:10:19.679 --> 0:10:23.720 which actually hampered rescue UM operations because apparently it's just 0:10:23.720 --> 0:10:30.000 like quicksand right now, Yeah, so in the case of well, 0:10:30.000 --> 0:10:32.560 in the case of anything other than a creep or slump, 0:10:32.800 --> 0:10:37.719 if you're talking about a quick landslide, it happens just 0:10:38.840 --> 0:10:42.240 like in a snap. It's it's going and picking up speed, 0:10:42.320 --> 0:10:46.760 but it is the result of years and years of 0:10:46.760 --> 0:10:52.320 of like slow steady erosion. Classically, it's not something that 0:10:52.400 --> 0:10:55.000 just happens out or it can be triggered. We'll talk 0:10:55.000 --> 0:10:57.760 about like earthquakes and stuff like that, but in general, 0:10:57.880 --> 0:11:02.320 it's the weathering down of objects. And I guess the 0:11:02.320 --> 0:11:06.359 difference we should describe between weathering and erosion is erosion 0:11:06.559 --> 0:11:09.839 is transporting the weather material and weathering is is the 0:11:09.880 --> 0:11:13.040 actual wearing down of that material. So they're different. So 0:11:13.080 --> 0:11:16.959 if you have a rock that's a nice, big solid piece, 0:11:17.000 --> 0:11:20.439 millions of years later, it's been weathered into a bunch 0:11:20.480 --> 0:11:25.800 of soil, and then as as as it's lost its composition, 0:11:25.880 --> 0:11:27.920 it can move more easily, and when it moves, it's 0:11:27.960 --> 0:11:33.600 being eroded. So erosion is the is the process of movement. 0:11:34.120 --> 0:11:36.840 The weathering is everything that leads up to that ability 0:11:36.880 --> 0:11:39.360 for it to be moved. Yeah, and weathering is important 0:11:39.400 --> 0:11:43.480 because it's your weathered landscape is going to be much 0:11:43.559 --> 0:11:47.000 more likely the landslide um. That's why you'll see them 0:11:47.000 --> 0:11:49.839 in more extreme environments where you get like tons of 0:11:49.920 --> 0:11:53.280 rain or like a lot of snow maybe uh, heat, 0:11:53.559 --> 0:11:56.280 cold water, and oxygen. Those are all things that impact 0:11:56.320 --> 0:11:59.600 weathering cause weathering. And there's there's two types of weathering. 0:11:59.760 --> 0:12:03.120 There's mechanical weathering and there's chemical weathering and mechanical weathering 0:12:03.240 --> 0:12:07.520 is basically, um, the material is broken down, but it 0:12:08.080 --> 0:12:12.560 retains its same chemical composition. Right it was, It's still 0:12:12.600 --> 0:12:15.319 the rock, but it was broken down into smaller pieces 0:12:15.360 --> 0:12:18.880 of itself, um, say by wind or something like that, 0:12:19.520 --> 0:12:22.640 or water lapping against it. Now, if you had that 0:12:22.720 --> 0:12:25.560 pieces of those pieces of rock that were in water 0:12:25.640 --> 0:12:28.840 that ultimately, over the course of years dissolved it, it 0:12:28.880 --> 0:12:32.080 would be in solution and it would no longer chemically 0:12:32.480 --> 0:12:36.719 resemble itself. That's chemical weathering. So like if you pour 0:12:36.840 --> 0:12:41.560 acid on your hand, Uh, it's gonna reconstitute into something else. 0:12:41.600 --> 0:12:44.600 On the other end, the whole that burns through it, 0:12:44.920 --> 0:12:46.800 the stuff that ends up on the table is not 0:12:46.960 --> 0:12:49.280 really the same thing as your hand. You just chemically 0:12:49.280 --> 0:12:54.800 weathered your hand. That's a pretty extreme example. Um. And 0:12:54.800 --> 0:12:57.440 then you talked about the constant state of movement on 0:12:57.480 --> 0:13:00.439 the Earth that's going on at all times, and that's 0:13:00.480 --> 0:13:03.680 basically if you're gonna have erosion, you're gonna have a 0:13:03.720 --> 0:13:07.000 deposit somewhere, and it's just a constant cycle on the 0:13:07.040 --> 0:13:11.280 earth of weathering carried away by erosion and being put 0:13:11.400 --> 0:13:17.240 somewhere else. In in cases of landslides the bottom of hills. Yeah, 0:13:17.320 --> 0:13:20.720 when we toward Guatemala, you Jerry and I and um 0:13:20.840 --> 0:13:24.720 or I should say me, Um, we we're at the 0:13:24.720 --> 0:13:27.360 site of a landslide that had happened. Um, I will 0:13:27.400 --> 0:13:30.120 never forget. Yeah, and they you know, you could still 0:13:30.160 --> 0:13:35.160 see in the sort of jungle like forest the swath 0:13:35.240 --> 0:13:37.280 that had been cut through years earlier, because all the 0:13:37.320 --> 0:13:40.360 stuff on either side was old growth and then the 0:13:40.400 --> 0:13:44.160 stuff through the landslide slow was Yeah, it was like 0:13:44.200 --> 0:13:47.319 it was much younger, Yeah, shorter, like a different kind 0:13:47.320 --> 0:13:49.720 of green as well. And they pointed out that we 0:13:49.720 --> 0:13:53.200 were like twelve feet higher than uh basically standing on 0:13:54.280 --> 0:13:59.040 uh yeah, the old village they were unable to recover 0:13:59.040 --> 0:14:02.680 about two deep people. It was really upsetting. Yeah, and 0:14:02.720 --> 0:14:06.440 I remember their children were running around, all these orphan children, Um, 0:14:06.480 --> 0:14:08.920 like they are just kind of they belong to the 0:14:09.360 --> 0:14:13.360 remaining village. Now. It was really something else. Well. Yeah, 0:14:13.360 --> 0:14:15.080 and just when they said, like, you're like twelve feet 0:14:15.160 --> 0:14:18.880 higher than just the whole land raised up because of 0:14:18.960 --> 0:14:20.760 this month's line. It was one of those ones that 0:14:20.840 --> 0:14:22.160 like you just kind of chewed on for a little 0:14:22.160 --> 0:14:25.040 while before you finally understood, like the full gravity of it, 0:14:25.080 --> 0:14:27.040 even though like while while I was standing there, I 0:14:27.080 --> 0:14:29.120 was like, oh this is nuts. Yea. Then the more 0:14:29.280 --> 0:14:33.000 I thought about it, think none of your got uh 0:14:33.080 --> 0:14:36.680 So the sediment, Um, we we talked about the deposition 0:14:36.720 --> 0:14:39.040 at the bottom of the hill. The sediment is known 0:14:39.080 --> 0:14:42.080 as talus, right, let's the official word for it when 0:14:42.120 --> 0:14:44.960 when it's from a landslide. Yeah, yeah, that's what's being 0:14:45.000 --> 0:14:48.240 carried down. And um, with erosion, there are five different 0:14:48.240 --> 0:14:51.080 things that can act on it, which are water, which 0:14:51.080 --> 0:14:54.160 we've covered in wind and then gravity of course which 0:14:54.160 --> 0:14:56.840 we mentioned, and then waves and glaciers too. And technically 0:14:56.880 --> 0:14:59.640 gravity is a part of all of them, right, Yeah, 0:14:59.640 --> 0:15:02.800 that's true, a part of all mass movement. But um, 0:15:03.640 --> 0:15:07.080 those five agents of erosion, there are different things that 0:15:07.160 --> 0:15:12.560 can trigger a landslide or a mass movement. Um. And and 0:15:12.320 --> 0:15:14.280 and really, if you think about it, all a mass 0:15:14.320 --> 0:15:18.600 movement is like a landslide, it's just erosion in at 0:15:18.640 --> 0:15:22.200 high speed. Sudden and high speed erosion is is basically 0:15:22.200 --> 0:15:25.520 what that is. Rather than taking millions of years to 0:15:25.600 --> 0:15:28.120 move from here to there through wind or waves or whatever, 0:15:28.600 --> 0:15:31.400 it's just happens in a moment, and it happens on 0:15:31.560 --> 0:15:33.960 mass all right, So you mentioned the triggers. We will 0:15:34.000 --> 0:15:40.280 cover those right after this message break. All right, So 0:15:40.480 --> 0:15:44.000 we mentioned triggers. Uh, the landslide always has to have 0:15:44.040 --> 0:15:45.800 a trigger, that has to be something to actually set 0:15:45.800 --> 0:15:48.920 it off. Even though it maybe years and years in 0:15:48.920 --> 0:15:53.920 the making, something finally pushes that button to make it happen. Um. 0:15:53.520 --> 0:15:59.320 It forces gravity to overcome friction. That's right. One of 0:15:59.320 --> 0:16:01.720 the things that we mentioned already in the case of 0:16:02.000 --> 0:16:06.280 Washington was water, and that is probably the most common 0:16:06.680 --> 0:16:10.120 heavy rainfall I know in California and Los Angeles. When 0:16:10.160 --> 0:16:13.000 you see houses slipping off the hill in Malibu just 0:16:13.000 --> 0:16:14.360 because they don't get a lot of rain, and when 0:16:14.400 --> 0:16:17.200 they do, things like that happen. Yeah, And it's either 0:16:17.360 --> 0:16:19.920 water saturating the ground and just making it so heavy 0:16:19.960 --> 0:16:24.320 that it flows downward, or it gets down in between 0:16:24.400 --> 0:16:27.400 the soil and the bedrock and just causes the whole 0:16:27.400 --> 0:16:32.280 thing to undermines everything. Either way, water equals a lot 0:16:32.320 --> 0:16:37.400 of movement. Earthquakes that can definitely trigger a landslide. Um. 0:16:37.520 --> 0:16:39.280 We've covered earthquakes. You should go listen to that show 0:16:39.280 --> 0:16:41.080 if you have, and it's a good one. But you've 0:16:41.120 --> 0:16:44.040 got the vibrating of the Earth's crust, and that UM 0:16:44.320 --> 0:16:47.520 is going to disrupt that friction pretty easily. Another big 0:16:47.520 --> 0:16:50.240 one is wildfires, which you would think, well, how would 0:16:50.240 --> 0:16:54.360 a wildfire trigger that. I'll tell you how UM. Vegetation, 0:16:54.480 --> 0:16:58.800 the roots of vegetation can lock soil into basically a 0:16:58.920 --> 0:17:02.840 totally solid, cemented state, and as long as you have 0:17:03.040 --> 0:17:06.560 thick vegetation on a slope, it's gonna be fairly stable. 0:17:06.840 --> 0:17:09.200 When a fire comes through burns out all the vegetation, 0:17:09.280 --> 0:17:12.920 it often burns the roots as well, leaving not only 0:17:13.280 --> 0:17:16.720 less stable soil, but actual pockets in that soil too. 0:17:17.080 --> 0:17:19.240 So now it's kind of pebbled, which makes it a 0:17:19.240 --> 0:17:22.680 lot more vulnerable to landslides after a wildfire. Yeah, I 0:17:22.720 --> 0:17:24.760 would I'm just guessing here, but I would guess a 0:17:25.119 --> 0:17:29.520 landslide could happen like even long after wildfire, Like if 0:17:29.520 --> 0:17:33.000 those roots die away, it would just become even less stable. Uh. 0:17:33.040 --> 0:17:37.119 And then volcanoes. Uh. Volcanic action is a big cause. 0:17:37.160 --> 0:17:40.840 And there are a couple of um different kinds of 0:17:40.880 --> 0:17:44.720 flows that can contribute to a landslide from a volcano. 0:17:45.119 --> 0:17:49.439 When it's called a pyroclastic flow, and that is after 0:17:49.720 --> 0:17:53.480 your dome has collapsed or during interruption, and these are 0:17:53.800 --> 0:17:56.520 super high speed. They've clocked him at four hundred and 0:17:56.520 --> 0:18:02.520 fifty degrees fahrenheit Alva flowing at you at four. I 0:18:02.520 --> 0:18:06.639 can't even imagine that, Like, can you imagine seven twenty 0:18:06.720 --> 0:18:11.359 four kilometers per hour? That's easier. Well, there you go. 0:18:11.520 --> 0:18:14.720 Then you just imagine four. Yeah, but I mean I 0:18:14.720 --> 0:18:17.199 don't even know what that looks like, you know, or 0:18:18.240 --> 0:18:22.120 de yeah, exactly. Uh. And then they are something called 0:18:22.119 --> 0:18:26.000 a lahar, which is an Indonesian word. And this isn't 0:18:26.200 --> 0:18:29.000 uh doesn't have to be during interruption, but it can be. 0:18:29.840 --> 0:18:32.840 And it is set off by water as well. Um, 0:18:33.160 --> 0:18:36.520 it's almost always near something called a stratovolcano, which are 0:18:36.560 --> 0:18:39.600 like super steep cones, and a lot of times there's 0:18:39.640 --> 0:18:42.040 either a crater lake or it's snow capped up top, 0:18:42.600 --> 0:18:46.160 and so that's the water agent. A lot of times 0:18:46.160 --> 0:18:47.840 it's the snow and it it sort of looks like 0:18:47.880 --> 0:18:51.040 wet concrete flowing downhill. Yeah. And it may or may 0:18:51.080 --> 0:18:54.280 not be set off during an actual volcanic eruption. It 0:18:54.280 --> 0:18:57.639 can happen anytime. Yeah, and it's it's much slower, you know, 0:18:58.720 --> 0:19:01.000 an hour, but still if you're in a golf cart, 0:19:01.040 --> 0:19:05.160 you're dead. Yeah, that's a good point. Uh. And while 0:19:05.200 --> 0:19:07.640 it's not fast, it has um a lot more rock, 0:19:07.880 --> 0:19:12.359 So it is one of the deadliest lahar is, I 0:19:12.400 --> 0:19:14.840 think because of just the sheer like you can carry 0:19:14.840 --> 0:19:17.240 like a big boulder. Yes, in the middle of that 0:19:17.280 --> 0:19:21.480 wet concrete, plus of volcano also. Um, it's just it's 0:19:21.640 --> 0:19:25.280 not very stable because the composition of it is usually 0:19:25.320 --> 0:19:28.640 pretty loose rocky soil. So yeah, if you had water, 0:19:28.680 --> 0:19:32.960 it immediately turns the slurry um. And when they erupt, 0:19:33.359 --> 0:19:36.120 they tend to shake the ground a little bit, which 0:19:36.119 --> 0:19:42.240 is what happened in the largest recorded landslide in Mount St. Helen's. 0:19:42.600 --> 0:19:46.480 Everybody knows the eruption, but there was actually an attendant 0:19:46.600 --> 0:19:49.639 landslide that's on YouTube you can check out. As a 0:19:49.640 --> 0:19:52.760 matter of fact, Um, we're putting a post up of 0:19:53.000 --> 0:19:57.000 just amazing landslide footage that you can check out on 0:19:57.040 --> 0:19:59.119 our website. Um, just go to stuff you Should Know 0:19:59.160 --> 0:20:01.560 dot com and check out that post. There's just a 0:20:02.280 --> 0:20:04.639 just some crazy stuff that people just happened to be 0:20:04.680 --> 0:20:09.320 filming and all of a sudden, the earth changes right 0:20:09.359 --> 0:20:11.880 before your eyes. And one of them is this Mount St. 0:20:11.880 --> 0:20:15.399 Helen's eruption where just the whole mountain is basically just 0:20:15.640 --> 0:20:19.679 melting in front of you. I remember that one, do you? Oh? Yeah, 0:20:19.680 --> 0:20:22.720 that was only four Yeah, I was nine, So it 0:20:22.800 --> 0:20:26.600 was on my radar that one traveled at speeds of 0:20:26.600 --> 0:20:30.919 a hundred and fifty miles and again Washington State, not 0:20:30.960 --> 0:20:35.119 getting a break, destroyed twenty seven bridges, about two hundred homes, 0:20:35.600 --> 0:20:39.760 miles and miles of road, and covered three square miles 0:20:41.480 --> 0:20:44.560 with debris. Yeah, that was a Mount St. Helens. Well, 0:20:44.600 --> 0:20:47.280 you know it was the landslide. Another another frequent hazard 0:20:47.440 --> 0:20:51.000 associated with landslides is you think about it, Um, when 0:20:51.040 --> 0:20:53.360 all of this earth is coming down, it's coming downward 0:20:54.320 --> 0:20:57.480 into a lower space, which is very frequently a valley, 0:20:57.520 --> 0:21:00.679 which is very frequently a river valley, which means that 0:21:00.760 --> 0:21:04.520 the river's damn now, so it's flooding behind it. Yeah. Right, 0:21:04.560 --> 0:21:07.840 so you have a flood, a flood hazard immediately, and 0:21:07.880 --> 0:21:12.040 then if that river or if that damn breaks, then 0:21:12.080 --> 0:21:14.600 you have another flood hazard down river all of a 0:21:14.600 --> 0:21:18.119 sudden two, which is something that's going on in Washington 0:21:18.280 --> 0:21:20.919 right now. Yeah, the same thing happened, and um, I 0:21:20.960 --> 0:21:24.159 think it's the most expensive landslide in US history in 0:21:24.200 --> 0:21:29.280 Thistle Utah uh in night, the same thing happened there. 0:21:29.359 --> 0:21:33.399 It damned up the Spanish Fork River and caused like 0:21:33.520 --> 0:21:36.600 much more problems just because of the flooding. And that 0:21:36.680 --> 0:21:40.240 was two hundred million dollar fix in ninety four dollars. 0:21:41.240 --> 0:21:43.639 And that was even when Reagan was in office. So 0:21:43.680 --> 0:21:48.160 it's not too much different from the two thousand uh. 0:21:48.240 --> 0:21:50.919 The submarine landslide we should probably talk about that is 0:21:51.400 --> 0:21:55.800 in the ocean, and that is you can you can 0:21:55.840 --> 0:22:01.240 have an earthquake under the ocean triggering a landslide underwater 0:22:01.359 --> 0:22:04.840 which will trigger a tsunami. Yeah, I can a one 0:22:04.880 --> 0:22:09.360 to three punch basically of natural disasters happening all in concert. 0:22:10.200 --> 0:22:12.240 Um that and then actually I don't know if this 0:22:12.359 --> 0:22:17.160 really technically counts, but it's seeing that um little bit 0:22:17.520 --> 0:22:22.960 triggered a memory of the Lake Pinier disaster in Louisiana. 0:22:23.080 --> 0:22:27.879 In Texico, was drilling in Lake Pinier and apparently they 0:22:27.880 --> 0:22:30.520 didn't consult the map closely enough, and they were using 0:22:30.520 --> 0:22:35.320 a fourteen inch diameter drill, and they drilled into the 0:22:35.400 --> 0:22:38.440 lake bottom, which was on top of a salt mine, 0:22:38.960 --> 0:22:43.359 and they drilled into an operational salt mine, and the 0:22:43.520 --> 0:22:47.480 lake got sucked into the hole in the giant whirlpool. 0:22:48.280 --> 0:22:51.520 Um that took about like thirty to fifty of the 0:22:51.560 --> 0:22:54.879 surrounding acreage around the lake in into the lake with it. 0:22:55.560 --> 0:23:00.000 Eleven barges were sucked in the um flow of water reverse, 0:23:00.119 --> 0:23:03.080 so it went from freshwater to saltwater. It sucked the 0:23:03.080 --> 0:23:06.120 gulf into it for a second, and then a couple 0:23:06.119 --> 0:23:08.520 of days later after they were like four hundred foot 0:23:08.560 --> 0:23:11.080 geysers as like these shafts were filling with water and 0:23:11.119 --> 0:23:15.080 the air was being displaced, and um, a couple of 0:23:15.119 --> 0:23:18.240 days later, after the water pressure stabilized, like nine of 0:23:18.280 --> 0:23:20.600 the bar just popped back up and like went back 0:23:20.600 --> 0:23:23.560 to floating after being sucked down into this diamond mine. 0:23:23.560 --> 0:23:27.320 It's crazy and then nuts and apparently there's footage of it. 0:23:27.320 --> 0:23:30.360 It's it's awesome. It's like just the most amazing thing. 0:23:30.720 --> 0:23:33.920 I guess more amazing than that is no one died. Yeah, 0:23:33.960 --> 0:23:36.600 there was one guy on the lake who was operating 0:23:36.640 --> 0:23:39.280 the drill. He got all and then there was a 0:23:39.280 --> 0:23:41.760 guy fishing on the lake and he zoomed his boat 0:23:42.160 --> 0:23:44.760 to shore and made it like win far enough that 0:23:44.840 --> 0:23:48.120 he made it, but I think three dogs died Lake 0:23:48.200 --> 0:23:51.159 Pen your p e I G N e U R 0:23:51.400 --> 0:23:53.800 disaster check it out. I was all excited and then 0:23:53.920 --> 0:23:59.560