The Big Fill Slide - And Landslides Generally
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Dr. Jesse Reimink: Does that mean you're always ready?
like, perpetually ready to record,
Chris Bolhuis: Stop asking. Ever. Have I ever said, because you ask this question all the time. Have I ever said, [00:01:00] well, Jesse, no, I'm not ready. Hold on. I need, I need a few minutes. Have I said that ever?
Dr. Jesse Reimink: Uh, not in the last, like, four years. Maybe in the first couple episodes. First couple episodes we did that a bit, but not recently. No, that's true. I want you to get your professional game face on. It's more of a signal of, Chris, hey, tighten it up, let's go. the, the red light. The red light is blinking, man. Let's go.
Chris Bolhuis: I can see the red light. It's right in front [00:01:30] of me too, Jesse.
It's not just on your end. So
I know we're going and, uh, you don't have to worry about me.
You just, you worry about yourself.
Okay. Can we do that?
Dr. Jesse Reimink: I've got fun, Chris.
Chris Bolhuis: You have an interesting Chris today. How about
Dr. Jesse Reimink: I have interesting Chris. Oh, this is very exciting. Okay.
Interesting Chris is
Chris Bolhuis: you, tapped into it right
Dr. Jesse Reimink: Slightly, maybe unpredictable, but enthusiastic. He's going to be passionate about something. Interesting Chris could have many, [00:02:00] many varieties of, Insight or Rance, maybe. Let's put it one
way,
Chris Bolhuis: I have a few, I have a few on this. Yeah.
Dr. Jesse Reimink: Okay, so this is a listener question. This mostly a listener question. We'll credit Ron with this. Ron, thanks for the question. brought up that we, we like to talk about, you know, geoscience news things and also pointed us in the direction that, Hey, there's some news about a place you guys are passionate about, which is the Tetons and the landslide that happened in the Teton Pass just recently.
at the time of recording, Chris, you're about to depart on [00:02:30] summer science. This will come out. while you're on Summer Science, and do you cross this road with the big yellow school bus? Do you go across Teton Pass or no?
Chris Bolhuis: No, we don't.
Um, but I've crossed the pass many, many times. everybody knows this. If you've listened to the podcast before, then you know that. Jenny and I and my kids have been in a rut for quite a while where we, we spend, you know, several weeks in the summer banging around a large part of the Tetons and we've been doing that for, for Cordova.
[00:03:00] So yes, we've crossed the Teton pass because, you know, I don't know how this came about. Jesse, do you, can I tell the story of the brewery? Do you want me to like talk about that?
I don't
Dr. Jesse Reimink: I've lost, control of you and this podcast, so
Chris Bolhuis: You know, you have interesting Chris today. so here we go.
Dr. Jesse Reimink: benevolent side of my dictatorial
role is coming out. I'm being benevolent now.
Chris Bolhuis: right. so Jenny and I. We went to Grand Teton Brewing Company. I don't know how many years ago. I'm going to just say six or seven years ago. [00:03:30] That's,
that's probably ballpark ish. And, we walk into this place
and it's pretty, it's in
Dr. Jesse Reimink: the
Idaho side
Chris Bolhuis: Yeah. Yep. Yeah, you got to go over Teton pass. And so we come into Victor and we saw a sign and go there and it's just this really cool, it's got a cool vibe to it.
And we had a deck of cards with us and a cribbage board. So we were just going to sit there, have a beer or two and, you just hang out with the kids and you get to look at the backside of the Tetons from this
place. So it's pretty amazing. It's [00:04:00] a view that I've said this before, that lot of people don't get to appreciate because I
think everybody, views it from Jackson hole. So I, we walk in and Jenny notices on the board where they're displaying the beer name. She, she says, Oh, Chris, they have Bitch Creek here. And we had just purchased Bitch Creek Ale at somewhere else in, in Wyoming.
And, uh, there was a guy sitting in the corner of the bar area there and he perks his head up and he says, Oh, did you like Bitch Creek? And Jenny and I look at him [00:04:30] and we turn our heads, you know, and it's this kind of older gentlemen. And, I said, yeah, we really did. And I kind of, we talked to him for just maybe 30 seconds or so. And I'd be like, are you a brewer? Do
you own this place? And he's like, I don't own it, but I'm, I'm the head brewer here.
And so we. I said, well, I brew beer. And and it, we just had a really good discussion. Then he's like, you know, grab your glasses. let's go for a tour and I'll
keep your glasses full. So he took us all around. yeah, yeah, It took us all around so we [00:05:00] spent way longer there than we ever thought we would,
but, just a good time.
So we've been going back ever since. It's,
it's a destination for us now.
So, but not, with the bus. Okay. Do we don't, I don't take, I don't, I've never taken the bus over Teton pass.
Dr. Jesse Reimink: Okay. Yeah. I mean, it's one of these like classic two lane winding highway roads, right? I mean, you kind of snake your way up and down on various sides. And we'll get into this, this episode. It's a complicated engineering project and feat for many reasons, but the story here [00:05:30] is that there was a landslide.
There's a landslide recently. It's called the Big Phil landslide. And we're going to talk about why that is, but the road is closed for, An unknown amount of time, quite a long time, probably, to fix this landslide. If you look at photos, if you go to Google and just type in Big Phil Landslide or Teton Landslide, you'll see some photos of this.
I mean, so there's an interesting story to this. There's an interesting geological story to this. And we're going to, I think, Chris, start zoomed in on the Big Phil Landslide and then zoom out to landslides generally, and then [00:06:00] kind of talk about this region, landslides in this region, which You've taught a lot about landslides in this region over the years, so the story of the Big Phil landslide is kind of an interesting one, right?
Like it's been, they've known that this road is a problem for a while.
There's always been some amount of what's called mass wasting or sort of downslope soil erosion. or mass movement. Mass wasting is movement downslope of mass. That's really kind of the definition, right? Is that how you focus on that? I mean, we've known that this [00:06:30] place is moving for a while.
It's just at what rate?
Chris Bolhuis: When you have steeply tilted sedimentary rocks know, you put a road on it too, then you add fill on top of those rocks and soil. and this is called the big fill because they added quite a bit of fill
material to make this happen. know, you just have the recipe for this kind of thing.
So as you said, they, this is not an uncommon phenomenon. In fact, Jesse, as I was looking into getting ready to do this episode, I saw a [00:07:00] map, did you come across this?
Dr. Jesse Reimink: I'm
Chris Bolhuis: A landslide map of the Southern Teton range there
in this.
So it's unbelievable, Jesse, it is absolutely shocking the number of landslides that have happened. that's all this was. This was not like a risk assessment. This was
Dr. Jesse Reimink: Just the number of landslides? Wow. That's really amazing. That's totally cool. So the story here is that this landslide just gave way recently, a couple weeks ago at the [00:07:30] time of recording, but we kind of had known that this road, this part of the road, and several parts along this same road, have been a problem.
Meaning, There is movement, and on the order of a millimeter per year, those things, that happens, that's fixable, you know, they go in and patch the road, and if you look at photos, you'll see a big patch in this part of the road that eventually gave way, so it had been patched before, over time, and, that's kind of natural, as soil settles gradually, that happens, but it's not a problem unless it [00:08:00] completely gives way, like this did, and this was discovered, Chris, by A motorcyclist actually was driving over it and actually had, I couldn't figure out the fate of this person, so
Chris Bolhuis: I, you know, yeah, that's a such a
Dr. Jesse Reimink: but I don't know that,
Chris Bolhuis: I'm not sure either. Um, I think so, but again, I, I'm, I'm not sure, but Yeah. this person was driving the motorcycle around this bend and the road. Just shifted about a foot. slumped down about 12 inches and it caused [00:08:30] him to lay down his bike. but if you think about that though, I mean, that's really bad that this accident happened, but you think about that, if that hadn't happened, the disaster could have been way worse because of this motorcycle accident, they started to assess the area. They looked at the crack and they started to assess it. So they saw that on June 7th, the day after this, it was moving down slope one inch per hour.
Dr. Jesse Reimink: Yeah.
Chris Bolhuis: Well then, just before it finally just gave [00:09:00] way, it was moving six inches an hour.
And so was, it all started, this kind of crescendo started because of this accident. And because of that, they shut down the road and potentially then a lot of other lives were saved.
Dr. Jesse Reimink: yeah, no, that's exactly right, Chris. And so those, those rates are important because we think of millimeters per year is sort of not a problem. You know, that, that happens, that's patchable, that's fixable. But when we start to get to obviously inches per hour, then this is an unsafe environment. and [00:09:30] the likely causes of this is Very common in the landslide world.
The most common cause of landslides is water in the system, saturating the rock or soil with water. And we'll come back to this topic. This will be a theme throughout the episode. This was an exceptionally fast snowmelt year, so temperatures rose rapidly, a lot of snowmelt, saturated the soil, actually saturated the native soil beneath the road fill, which the mud in that area.
native soil, [00:10:00] then gave way. So the native soil underneath the road fill gave way, then took the road fill with it, which caused this big fill landslide.
Chris Bolhuis: that's right. The water essentially, Jesse, exploited the boundary between the fill material and the native soil and the rock below it.
You know, they're just not the same lithology. they don't have the same porosity and
Dr. Jesse Reimink: Let me interrupt you right there, Chris, because that's a really important point, because what we typically try and not put into soil that we're filling in a road with is clay. Because we've talked [00:10:30] about clay and we'll talk about clay again, but clay
gets really slippery when wet. It's a slippery when wet road sign on it, right?
and there's a You know, clay layers down in the native soil horizons that, got saturated. And then this is a mechanism to start the slip going on and then the landslide. So Chris, I, is now a good time to kind of back up a little bit or zoom out a little bit and talk about landslides generally and leave the big fill and come back to this region later.
Or, or is there
Chris Bolhuis: just,
Dr. Jesse Reimink: to say?
Chris Bolhuis: Yeah, I just have a couple of things, maybe just [00:11:00] real short that I want to bring to the table with this big fill slide that took place. One is that, we had some really, really warm days and warm nights and that added water to the system from melt, snow melt from above. You had an already high groundwater table. And then, there are other things going on
that contribute to this too. You have climate change. Adding, more severe storms and more severe seasons to this picture, plus Jesse, [00:11:30] the impact of forest fires,
which are of course probably tied to climate change as well. know, it's just kind of like, uh, this perfect storm really that led to this situation.
But again, they've always had their eye on this because it's this very, very steep area A lot of fill was involved by the way to Jesse, the fill that adds weight
to an already, over steepened slope so they had their eye on this. There's no way to predict something like this. you know what I [00:12:00] mean?
Like you can't, there's no way to forecast it, but you know that it's something is going to happen at some point in the future.
Dr. Jesse Reimink: I think that's a really interesting point touch on, Chris, is first of all, I didn't know before looking into this that this was a landslide that included non native rock and soil or infill that this was road infill fundamentally underneath the road. This was human added soil and rock and material that filled [00:12:30] in underneath the road.
And that was on top of the native soil, right? So the native landscape got filled in to support this road on a bend in a switchback in the mountain pass, right? So that's one thing to kind of keep in mind, or one thing that's important. The other thing to keep in mind here is that, as you said, this was a known area, but not necessarily a problematic area.
And that's something that I don't think is necessarily intuitive. We think in our sort of basic, you know, human mind frame, if the [00:13:00] soil is moving at all, it's a problem, but actually that's not the case. Like soil is kind of always moving. And so the engineers always consider it to be moving. It's the rate that matters, right?
So very slowly moving doesn't matter.
Very fast moving does matter and catastrophically moving like this does really matter. So if it's moving slowly and predictably, that's not a problem. And that's what this was doing, you know, prior to this year. And then, as you said, all the factors that contributed to this made this what's called a catastrophic landslide, which means it, it slumped [00:13:30] away and it's gone now.
So that I think is a really kind of important thing to, to touch on there that I think that we don't often appreciate the fact that Soil is always moving. It's just the rate that actually matters. So anyway, should we move on and sort of zoom out here? Because I want to ask you, Chris, what do you teach?
what do you talk about in your class? Cause you know, you teach effectively AP geology and you cover way more content than I do in the college level geology class, just cause you have a full year really to do it. How much do you cover in mass [00:14:00] wasting?
And do you get into the differences between slides and falls and topples and all that kind of stuff? Yeah.
Chris Bolhuis: that's a big question. That was a typical Jesse Reimink question right there. Uh, you know,
Dr. Jesse Reimink: giving you the freedom to take it whichever
way you
want.
Chris Bolhuis: parts on it.
Dr. Jesse Reimink: Yeah. You get to pick whichever one you want.
Chris Bolhuis: Jesse, well, first of all, I want to ask you, do you, get to teach mass wasting in your class, your equivalent class at Penn state? You
do. Okay.
Dr. Jesse Reimink: And again, I, because I teach the engineers, [00:14:30] I
kind of have to, you
Chris Bolhuis: Oh, yeah, for sure.
Dr. Jesse Reimink: You know, if it was, if I was teaching,
Chris Bolhuis: spend on it?
Dr. Jesse Reimink: you know, not a lot as with all of the things, but I cover the basic differences between the rates of flow across the different categories of mass wasting, basically, you know, what the, the differences are.
And then we kind of get into the categories of, how the, like how the mass is moving down. If it's falling, that's different from, if it's slumping versus different from creep, you know, so really
Chris Bolhuis: Right. Yeah. Yeah. [00:15:00] Okay. I do the same thing. I covered the basic categories with, you know, falls and slides and flows and creep. and I do that, I love, first of all, I want to just say mass wasting is actually one of my favorite things to teach.
It's an interesting thing because my students, when, when we first get into mass wasting, they look at the word mass wasting and it doesn't make sense to them.
Like, what the heck is this?
Well, you know, why, what is mass wasting? What is the thing that you're speaking of right
now? And that's [00:15:30] always an interesting thing, but what I've done Jesse is I have compiled because over the last decade, there are so many events that have been recorded video wise. And so I've compiled the
best ones. And I just put together a presentation of these separate events that are just so gripping. I
mean, I don't, I don't know how else to say it. They're amazing. And then if you use Google earth and, [00:16:00] diagrams that geologists have drawn of the area that, this event happened, then you start to look at, okay, why did this happen here?
alright, first of all, was this a good idea to put a road here? You
know, um, are the rock layers tilted the right direction to put a road in this particular valley?
You know, because there are things that you should do and there are definitely things that should not be done,
and it's amazing. And shocking to me how [00:16:30] often things are done in a way that just doesn't make any geologic engineering sense at all,
Dr. Jesse Reimink: that kind of came to my mind in looking at this. I mean, this road was built 50 plus years ago, right? And, this pass and it's been, It's been a good one. I mean, it's it's lasted a long time, surprisingly, given the terrain it's going through. I mean, it's pretty impressive that, you know, 50 some odd years ago, or maybe even more now, that engineering was such that something could be constructed in a stable way.
I [00:17:00] mean, as frequently as we see and hear about landslides, and we'll come back to this, like you pointed out, the Southern Tetons landslides are everywhere. I'm kind of impressed that a road lasted as long as it has without, sliding away with, some events, right? you have to learn from these past times.
I don't know if they're mistakes or not, but, past events, right, to plan for the future, so that's a really nice way to do it, I think, is to, to watch all these examples, and, and,
watching them is just such a visual thing, it's just, they're so visually astonishing [00:17:30] when you see, millions of tons of material flowing downhill, it's crazy.
Chris Bolhuis: Yeah. It's a fun thing to teach because it's so gripping that way. It's, as visual as you can get.
And so I just use these then as mental cues and we break them down and talk about them.
And I love it. I don't know. It's just so much fun for me. It's one of my favorite things to teach, which
I don't know if that's surprising for you or
not, but you know, when
you look at these, they have common denominators though. and so let's talk about the role of water,
[00:18:00] in mass wasting events in slides and flows and creep and all of they've, the role of water is undeniable and I break it down and I say, well, water does three things. when you add water to rock, or when you add water to soil, or when you add water to fill like the big fill here, what happens? Well, water makes Whatever it's saturating, whatever it is filling the pore spaces in, it makes sediment lose its cohesion. if you think about [00:18:30] like a, just a pile of sand,
those grains are in contact with each other. But when you add water to that and it fills in the pore spaces, any kind of jiggling motion at all is going to cause water to get in between the grains they lose their cohesion and they become slippery then. Water makes sediment heavy, That's another thing you think about, like the building of retaining walls. This is, you know, retaining wall 101 is you have to give the water behind the wall, a place to go, [00:19:00] because if you don't, water's going to collect behind
your retaining wall, and it's going to cause it to tilt because water's heavy, really heavy.
So that's number two. And then the third thing is water makes my nemesis clay. It makes it slippery. So those are the, the three,
Dr. Jesse Reimink: Chris hates clay. It's just so fun to bring up clay when clay comes into the picture.
Chris Bolhuis: Yeah.
Yep. So those are the three [00:19:30] things that, the, what I just summarize
as, Hey, this is the role of water in mass wasting
Dr. Jesse Reimink: totally. And the role of water is obviously a massive one. I think that's, pretty clear. You've laid it out perfectly. There are obviously other things that can affect or, trigger a landslide. And I think one obvious one is like any kind of shaking, any kind of ground shaking, earthquakes.
We'll talk about that. volcanoes erupting that are also shaking the ground, right. Or changing the distribution of soil. I think the [00:20:00] other thing that we should talk about here is the human impact or the human drivers of landslides, because we can do, or, and we do do as humans a lot Induce landslides in some way.
So deforestation, we talked briefly about that. This one for me is one that really stands out in my mind because when we were growing up, we always would go to this lake in northern Michigan, and there's a big hill on the other side of the lake. Michigan's very forested, has this old growth forest.
And so it was always forested. Then somebody started [00:20:30] building a house there. And so they, Cut some of the trees down, sort of built a flat plateau up, and, and we're going to build their house there. And then, Above where the house was, where they cut down a bunch of trees, a big slump formed and a landslide formed.
I don't know if it happened very quickly or if it slumped over the course of a season or a year or something, but you could see this big scar on the landscape that was the sort of bowl shaped depression of what's called a rotational landslide where you get that The land kind of kind of scoops downward and [00:21:00] slumps downward with this curved plane behind it.
Looks like somebody took a tractor, just took a big gouge out of the hill, basically. looks like Chris Bolhuis got on his tractor and was gouging at the hill with, with the shovel there. Um, but. Deforestation is a really important one, obviously. Blasting, mining, any kind of altering of the landscape with, building a road somewhere, we can an unstable slope over long timescales.
Chris Bolhuis: Yeah, that's right. And we do this all the time too, with building roads and, you know, [00:21:30] developments and things, which is over steepened slopes,
whenever you have a steep slope, you're going to have an area that's built. Could very well be prone to mass wasting kind of events.
So over steepening of slopes, and we call it in geology, we call that the angle of repose, the steepest angle that that slope can remain stable. and when you go beyond that, it's going to slough, it's going to slump, it's going to move to become more stable, that's another human kind of impact [00:22:00] thing. that happens a lot. Yeah.
Dr. Jesse Reimink: can I maybe throw some statistics in here, which I found, which were quite interesting, Chris, so I found a report on, The frequency and the causes of significant landslides now significant quote unquote that's a squishy definition, right? But it's estimated that between 1980 2018, there were over 15 million rainfall triggered landslides. landslides, significant rainfall triggered landslides around the world. That's about 400, 000 per year of [00:22:30] rainfall triggered. So that's, water as we've talked about, right?
That's water. If you look at the landslide hazard map globally, it's where there's high mountains, that's where it gets really red, and lots of landslides, but also mountains and wet, lots of rain, humid, tropical climates with a lot of rain, because the weathering is so much more, you've got soil there. All those things go into it.
The average annual number of earthquake triggered landslides, significant earthquake triggered landslides, is around 130, 000 per year. So 400, [00:23:00] 000 rainfall based ones to 130, 000 earthquake triggered landslides. Okay, Chris, question for you. Is that more or less than you would have thought?
Chris Bolhuis: shockingly more
earthquake ones,
Dr. Jesse Reimink: that's exactly what I thought. First of all, I thought the numbers are astonishingly high. 400, 000 per year of significant ones was, I thought that was way, I would have never guessed anything in the hundreds of thousands per year. I would have guessed, you know, 000 or something, but then I I'm, I'm with you.
I would have [00:23:30] thought there would be way more rainfall ones than earthquake ones, not like four to one ratio
roundabout there.
Chris Bolhuis: Jesse, two things popped into my head as you were talking about this. One is, you know, you and I we're from Southwest Michigan and we have the spectacular dunes.
And they're big These are big, big dunes. They're big and they're steep. And so, I spend actually a lot of time, a lot of the stuff that I show my students, the images and videos from mass wasting is along [00:24:00] the shorelines of Lake Michigan, because I want them to look at things a little bit differently when you can see the scarps from recent movements
that have happened on these dunes.
You if you think about it. how does a sand dune become over steepened along the lake shore? Well, if you have high lake levels and then throw in a couple really doozy storms, the waves are crashing into the base of the dunes and washing that sand back out
into the lake. It just [00:24:30] undercut the base of the dune and then you have these homes on top of it, right?
and so the homes, well, what are the homes doing? One sweating,
you know, they're, they're, they're nervous about
it. It's constantly on their mind. And, the other thing is though, is that the homes add weight. to the dune. so again, that's another trigger to mass wasting is the addition of weight. So, mass wasting to me, Jesse, is this just fascinating interaction between [00:25:00] geology and humanity.
Dr. Jesse Reimink: Totally, it's
totally, and it, you know, it's where the rubber meets the road, These are the things you have to think about if you're building a house especially now, I mean, you just, you see these reports from the Carolinas all the time about how homes are being swept into the ocean because of, you know, increased storm activity, or they're just building it on a cliff, an unstable cliff.
And a lot of these, these buildings go back many years before we really understood the full
repercussions of landslides and erosion and maybe increased erosion because of climate [00:25:30] change. So I totally agree with you. It's such a. It's just an amazing thing to teach and to focus on and to think about because it's so impactful and so dead obvious right in front of your eyes.
Chris Bolhuis: I have a question for you, Jesse. What do you think the homeowners are doing to slow the process down? I mean, these are really, big, expensive.
These people have money.
And
Dr. Jesse Reimink: I've
seen Chris. the ones I've seen up in the northern part of western Michigan [00:26:00] there, put big boulders right against the, the, the hill slope there, big, huge boulders to kind of prevent the wave action from eating away at the dune, because, I mean, dunes are very unstable, so if you get to the angle of repose with a dune, it's gonna erode all the
way up to the dune face, right?
So, You You can't undercut a dune. Um, I've seen that. I've also seen big concrete pilings going down below lake level, kind
of, you know, or like built into the, into the dune to kind of help stabilize the dune a bit. I don't know.
What, what [00:26:30] have
Chris Bolhuis: So Jesse, how, how do they get those big, cause they're big boulders.
At the base of the dune. you have an idea on how that process plays out?
Dr. Jesse Reimink: it can't be that they chuck them down the hill, is it?
Chris Bolhuis: It's not.
they come in with these barges,
you know, so the, yeah, the float a barge right up to the shore with a crane on it and just
offload these big boulders. Yeah. And then. So Jesse, real quick then, what, why, what do the boulders do? How does this stabilize the [00:27:00] base of the
Dr. Jesse Reimink: Yeah, so a lot of the erosional activity will take place in the winter months, typically storm or the storm months, fall is a good one for storms on that part of Lake Michigan. And so basically what the big boulders are doing is they're just dissipating big storm wave energy from hitting the cliff face.
So, if you go there on a calm day, you can see there's no erosion happening because the beach and the water levels are pretty low. quite far away from that, dune slope, but the storms are really what eats away. Big storm waves come crashing in, so its like a, any kind of [00:27:30] seawall mitigation measure where it's just dissipating the storm energy, the storm
Chris Bolhuis: Yeah. It's taking the energy away. That's right. You got it. Jesse, one other thing before we transition into just mentioning briefly, two famous, uh, You know, mass wasting events in
the Teton region. the other thing that I want to talk about that I focus on from a pedagogical standpoint with my students is paying attention to the slope of the sedimentary rocks.
Are they dipping in the same [00:28:00] direction that the slope of the land is going? that's another really important consideration. And also the kind of. angle at which the foliation, if you're dealing with metamorphic rocks,
if they're foliated, that's parallel to the direction of the slope too.
Those are things that, you don't want to have a house at the base of that, or you don't want to have,
you know, put a road at the base of that kind of thing.
so those are just, that's another trigger. It's another player in this whole mass wasting kind of
Dr. Jesse Reimink: [00:28:30] Totally. Totally. I think that's a really important one, Chris. And before we transition, well, let's transition now to we're going to focus on a couple of landslides that have happened in the Teton region. One of which we talk about in our Grand Teton National Park audiobook, which is available on the Camp Geo app.
If you go to the first link in your show notes, you can download the app and get access to a bunch of stuff. And you'll see some cool images of these because it's pretty hard to show you images with, with a podcast here. But if you go to that, you'll get some. Cool images that show one of them, the Gros Ventre slide.
But Chris, I want to just mention, [00:29:00] talking about the structure, we're going to talk about this more with the, with the Gros Ventre slide, but I saw the Franck slide, which is one of the largest landslides in North America. It might even be the largest. I can't remember now.
I saw it in grad school. It's in Alberta,
but the entire mountain is an anticline. So the mountain was an anticline and it really the sort of mountain faces
followed the anticline.
Chris Bolhuis: define what an anticline
Dr. Jesse Reimink: Yeah, so an anticline is take rocks and fold them, fold the edges down so that it looks like an A. I always think anticline looks like [00:29:30] an A.
and so you, you take two
pieces of paper and, and Yeah, and you fold the paper down. It's a, it's a upside down U or an A. so this mountain was an anticline. So both sides of the mountain actually had what we call unstable slopes because the slope was paralleling the sedimentary layering and sedimentary layering as, as a weak layer.
And so one entire side of the mountain fell off, it was limestone on top, so the limestone's a cliff former, and kind of hung on and formed some steep cliffs, and then [00:30:00] eventually it gave way. But it was a huge landslide, kind of really devastating, pretty tragic loss of life there too, kind of decimated the town of Frank.
Anyway, this is Turtle Mountain has this, this anticlinal structure to it. So this is not unlike the Tetons, which we're going to talk about. What are the two, Chris? Cause you showed me, I think if I remember correctly on Summer Science, when I went there, we went to the Hebgen Lake, Quake Lake,
is that correct?
We went there, right?
Chris Bolhuis: Yeah, we did.
We did. [00:30:30] I took you there. I
don't go there anymore.
Dr. Jesse Reimink: you don't. Okay.
Chris Bolhuis: I don't. Yeah. but it's a beautiful area and the geology is amazing. I just, I have to pick and choose Jesse. Yeah. I'm at the stage of my
Dr. Jesse Reimink: Yeah.
Chris Bolhuis: when,
Dr. Jesse Reimink: You've got to pick and choose
that one. So what is the quick and dirty geology of Quake Lake? I think that probably
gives it away a little bit, but, but what, what is it
Chris Bolhuis: so it's a beautiful valley where this happened. so actually this is just Northwest of Yellowstone national [00:31:00] park. at 1137 at night, 7. 5 earthquake happened. It was actually a massive, well, Jesse, it's a normal fault that ripped through this valley and the displacement was in places 20 feet, which is a lot. Amazing. That's a lot of movement that happened in, just a really a matter of seconds.
anyway, that violent shaking caused the mountainside, which was steep.
we talked about the angle of repose. I mean, this was not stable.[00:31:30]
That shaking just dislodged. The whole mountain side and it slid down and it dammed the Madison river.
And then you have quake lake, which is the lake that formed behind now the earth and dam that
was blocking the Madison river and it rose rapidly.
This was a, this was a national event. I mean,
they brought in smoke jumpers and hot shots and all these people that are used to fighting forest fires, they dropped them in to do. rescue because people were trapped. People were [00:32:00] climbing trees to escape the rising water. you know, another thing really that is just amazing about this earthquake is when that mountainside came down, that mass wasting event. It fell and it pushed air out from underneath the rock and it was hurricane force air. I toppled trailers cause there were campgrounds all up and down the
valley. And, just the stories from, from this are, they're really amazing. it's a compelling place to go. There are [00:32:30] still a number of people that are buried beneath where the slide happened,
where it crossed the Madison river.
Dr. Jesse Reimink: Chris, two quick things about this is that, I mean, we're talking about a massive landslide that created a lake that is up to 100, 120 feet deep behind it. So this is a big landslide that filled up a valley, filled up the valley with debris and dammed, as you said, the Madison River. So this is no small event, it's no small lake.
Now there's mitigation, you know, there's a spillway over the earthen dam and all this kind of stuff, to kind of, [00:33:00] prevent it breaking through, which we'll talk about the Gros Ventre slide next. Uh, but, other thing is that that's a co what you talked about, about the air thing, the, the air kind of flowing out from underneath this, when we get really rapid rock falls or landslides, and really they're more common with, with, uh, Falls, or things that are happening really rapidly, they kind of ride on a cushion of air, because the air cannot escape out from underneath of the mass that's moving downhill quick enough, so they end up kind of riding on this cushion of [00:33:30] air,
compressed air that can't escape as quickly, and so they end up accelerating downslope, and this can be really, really rapid, because of this process, the, how quickly this can happen.
Chris Bolhuis: you, Jesse, you and I have talked about this before in Yosemite National Park. We have rock fall events that are very, very common.
These massive slabs break off these walls and the air that gets shoved out from underneath this crashing rock will snap off these giant redwoods.
Dr. Jesse Reimink: crazy.
Chris Bolhuis: [00:34:00] amazing.
unbelievable force of,
Dr. Jesse Reimink: it's something that I, that is an, a repercussion of mass wasting that I do not think is obvious at all that it would happen. You just do not think that this is so much material, So much mass that's falling so quickly that literally the air underneath of it cannot escape.
So
it creates a cushion of compressed air. That is just something that we have to highlight because that's
Chris Bolhuis: I know, I don't,
Dr. Jesse Reimink: speaks to the power of these things.
Chris Bolhuis: I agree, Jesse, but you said something, but you [00:34:30] just glossed over it and I want to double click on it because it's riding on a cushion of air, which is a positive feedback loop,
because it makes this thing then move much faster than it should be able to move. If it weren't riding on a cushion of air, it would, it would be a much slower movement,
but this thing, these falls as they crash down into the valleys below.
So, They're moving really, really fast, and it's because of the air that they're riding on, essentially, and
pushing out from underneath them.
Dr. Jesse Reimink: It's
[00:35:00] just it's an amazing feature and a traumatic and devastating feature of these things. So Chris, um, speaking of earthen dams,
the Grovant slide, which
we have a whole chapter
Chris Bolhuis: Jesse? Do you know how to spell Grovant?
Dr. Jesse Reimink: GROW,
uh,
no
Chris Bolhuis: Ventre.
Dr. Jesse Reimink: this, this is GROS space Capital V-E-N-T-R-E, gtt. This is a landslide, Chris you'll tell the story of, but we, We have a whole chapter on this in our Grand Teton audiobook with [00:35:30] cool images to show you where it is in the Grand Teton area, in the Jackson Hole area, but it's a really cool story. Chris, what's the short version of the story?
Because the earth and dam thing that we talked about before, except there's, there's some other events that happen, right?
Chris Bolhuis: Yeah, I just want to make sure everybody understands that where this slide happened in the Gros Ventre range, the Gros Ventre range is just east of the Tetons.
So you have Jackson Hole, the valley, the Tetons are on one side and the Gros Ventre range is on the other side. So where the slide happened is in a [00:36:00] beautiful, beautiful area. and so the, you know, the short of it is, is that this rancher he kind of knew something was not stable with his ranch. you know, he heard noises and he heard water. And, and so he kind of suspected that something was going to happen. So he just sold it.
And so
somebody
bought it and, you know, couple of years later, the guy was right, you know, it gave way and slid down into the Gros Ventre river and it dammed it [00:36:30] and same thing, massive lake behind the earthen dam now. and this was just a, a really, really tragic, people lost their lives. People lost their homes and their livelihood. but this was, you said that the Frank slide was the biggest in North America. This one was the biggest in the United States history right here. So it's a lot.
Dr. Jesse Reimink: It's, it's, it's a lot. Yeah. eventually the earthen dam gave way. And then, obviously sort of flood downstream because of [00:37:00] that. So very different, but I want to I want to come back to the reason why, right? Chris, you, talked at the beginning that there's different mechanisms for landslides that we're going to talk about.
And the Growvat one is, again, water's involved, water's certainly involved here, because the rocks are sloped. downhill, if that makes sense. So the rock layers are tilted at sort of a similar angle as the hill slope, which means that it's quite easy for a big block to slide [00:37:30] downhill.
That's the same thing as the Frank slide, where you have rock layers that are tilted downslope. That makes for a really weak layer, A weak layer that is gravitationally unstable and it can slide down into a valley very easily. So the Grovant and the Frank slide, that's what was going on. Hebgen Lake or Quake Lake, that was an earthquake that triggered that landslide.
Right, Chris? So different phenomenon, different, structural implications or different structural setups to the different landslides [00:38:00] here. But Chris, you say this frequently, that like, you know, the Tetons are just spectacular, muscular mountains, and they're the youngest mountains, and they're beautiful, and that means they're active in the erosional sense as well, right?
That means that they are eroding, actively eroding in front of us sometimes, and this is one instance where that is true. That's the case. It's ongoing. We can see erosion happening, sometimes slowly, sometimes catastrophically.
Chris Bolhuis: that's right. And you can see the scarp from the Gros Ventre slide. it's [00:38:30] almost a hundred years ago now. And scar on the land it's hard to miss, you
Dr. Jesse Reimink: It's obvious. It's obvious from satellite imagery even. You You pulled a nice Google Earth image for the audiobook here, and it's just a totally cool one. So, Chris, just to end on, this is a very active, tectonically active region, the Tetons, so there's been a lot of proposals.
Coming back to the Big Phil landslide and the Teton Pass, you know, how do we not have this happen again? There have been proposals for tunnels or bridges. There was actually a bridge that was [00:39:00] built, almost finished, and then in 1970 it was taken out by a rockfall that it was engineered to not be taken out by, but a big rockfall came in and took out the bridge.
So that's a concern. That's a going concern in all of these areas. Tunnels are ridiculously expensive. I saw an estimate for a billion dollars, plus half a million dollars a year in upkeep for a tunnel in the Teton Pass, which I live in, in Pennsylvania and there's, there's a lot of tunnels to the Appalachians, but they were built actually in the railroad era.
So they were built for railroads. [00:39:30] And now we put highways through them. when Eisenhower was, was putting the highways in place, they used a lot of those railroad tunnels from the sort of, robber baron industrialist era. so tunnels are a bit impractical, uh, potentially there in the T towns, or at least at the moment, prohibitively expensive.
So, It's just a really interesting area, Chris. And I look forward to seeing this map of the landslides in the Southern Tetons. you got to ping me that when we get off recording here, cause
that,
that,
that'd be very cool. Um, one thing to end on Chris, I, uh, you probably saw this too, there was an interview with the [00:40:00] Wyoming Department of Transportation's chief geologist, James Dayhill, and he had a quote that I just, it made me think of Chris Bolhuis. His quote is, Erosion never stops, just like gravity never stops. I thought that was a great quote, I just thought of you man.
I thought
this
is something Chris Bolhuis will love.
Chris Bolhuis: I thought of myself too when I read it.
Dr. Jesse Reimink: That's
Chris Bolhuis: I did.
I'm like, that sounds like, something I would say
Dr. Jesse Reimink: It does. It does. That does sound like it. [00:40:30] Erosion happens, man. Erosion never stops, just like gravity never stops, man. If that isn't a crisp Bolhuisism, and you know what, you're probably going to swipe that and you're going to start using it in class. And then every student from 2024 onwards is going to think, That's a Chris Bolhuisism.
Chris Bolhuis: That's absolute. They're not going to know who Dayhill is. They're going to know. Oh,
Chris Bolhuis said this a long time ago. Guy's a genius.
Dr. Jesse Reimink: to me. That's
Chris Bolhuis: Hey,
you know
Dr. Jesse Reimink: never stops.
Chris Bolhuis: I know what my skills are and my skills are recognizing good things and then I steal them.
Dr. Jesse Reimink: That's perfect. [00:41:00] Who
doesn't? Who doesn't, man? Uh, well, this was, uh, turns out to be a little bit longer episode than we were originally planning
on, but I think it's, it's interesting. It's fun, it's timely, and good news is the Big Phil landslide was not tragic, uh, at least immediately tragic, although it's
disrupted a lot of people's commutes and lives and daily lives that, uh, nobody lost their life in the event.
So,
Chris Bolhuis: That's right.
Dr. Jesse Reimink: and that's the, the short of,
Chris Bolhuis: to Ron.
Dr. Jesse Reimink: yeah, thanks,
Ron, for the, for
the
good news. The great question, the great nudge in this direction. It's [00:41:30] been awesome. so that's a wrap. There are two ways to support us. First, you can go to our website, planetgeocast. com. there's a support us button there. We always appreciate that. You can also download our app, the Camp Geo app. If you go to the first link in your show notes, that will direct you to the app store. We can download it on your mobile device. We have a lot of audio books for sale there.
We also have a ton of free content. Basically the introduction to geology, the class that Chris teaches at the high school level and I teach at the college level is there with all sorts of images and the geology of the [00:42:00] grand Tetons, which we just talked about is also available for sale right now. Send us an email, planetgeocast at gmail.
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Chris Bolhuis: Cheers.
Dr. Jesse Reimink: Peace.
