As a resident of the Western NC area and an engineer, I really appreciate your videos. Your ability to explain these concepts in layman's terms is very helpful for people to understand this geologic event we witnessed.
One of the things I've noticed about these devastating landslides, is the bigger ones start way up on a steeper and higher mountainside and bring a lot of debris, compared to smaller ones that might go over a road or something and are not as bad as landslides like Stoney Fork and other areas. I worry behind our house but it's not a steep and tall mountain, but Sugar Mountain is behind and above us with a lot of development. I know there has been a landslide next to where we live many years ago and why it worries me. I feel like I'm having a geography class every time I watch you and I thoroughly like it knowing I'm going to learn more every time. You are a great teacher and explainer!! Knowledge is everything!
Another incident that was in close proximity to the Black Mt Range. Seems like in every direction from Mt Mitchell it was significantly worse than other places, as far as slides/flows.
Dang. Nearly 1600-1700ft vertical drop in less than 1mile of distance. Wow. That is WILD I love watching these videos and marrying the information on maps on some hiking apps I use. These videos really help to make sense out of what I've been seeing over the last 2+months These videos will also provide future generations with information as a historical reference. We are all being educated for free, and should be very thankful. I know I am.
I used to work at a place that made a fine grained PVC plastic. Up in the bins it would pack to between hard packed snow and cement. Stick an air line in the right place to fluidize it and it would run out like water.
exactly the same process. I use glass sandblast beads to model fluidized stuff like this. you can pile up a cone of them and give a tap and it turns into a puddle of them
Great breakdown, as always, of some of the dynamics behind what was a very surreal day. I've always heard that streams are surface expressions of the water table. We had so much rain that day it felt like the water table was sitting 1-2 inches above ground level because that was how much flowing water was on every surface of the mountain. Until a couple hours after it stopped really raining things were very weird.
yep, about right. if the whole surface flowed, it means full saturation was reached and overland flow had begun. at that point, everything is straight runoff and floods the streams massively. it’s like the whole landscape is a parking lot at that point.
I live in a creek bottom at the base of a ridge and sheet flow like that is a regular thing after a couple inches of rain. Amazing and a little scary .
You create the most helpful videos! You explain these concepts so thoroughly and make it easy for those of us who are not experts to visualize. Your paint illustrations are clear and concise, even while showing difficult concepts. Thank you so much.
Thanks for the effective visuals and explanation of debris flows. They were very useful for me personally to understand the physical events that resulted in these flows. Well done. Look forward to more great content.
I went to Tim Burleson’s page and seen they’ve had more flooding. The creeks are full of sediment and just a little rain now is causing flooding again. So sad.
Another very good explanation. Everyone of your vids teases out and vastly adds to knowledge I learned in my ocean engineering and oceanography studies. I really enjoy these, thank you
Never heard it explained this way. Very interesting and helps explain the behavior coming down the hill and once it comes to rest in the valleys. It sounds like it’s more or less due to waters inability to be compressed
essentially yes. an “over-pressure” scenario. sometimes the term “undrained loading” is used, meaning the load squeezes the water and it wants to escape but can’t
That was great! That ol phrase: "You learn something new every day"... thanks for making it easier to actually understand what's going on! Love these videos and I did learn something new yet again! Love these videos 🙂
How would you classify this event......a hundred year.....a thousand year or ten thousand year event ? Your channel is one of my favorites...Thank you !
tough to do because those are really just ways to express likelihood of occurrence…you might get another in 10 years! I suppose I have thought that I don’t really see river flooding effects like this event in the landscape, which would suggest it was bigger than anything in a long time. that said, I might not know what to look for! more on this idea in next video…
Excellent, understandable explanation! I was wondering if over time, rain water settles through the soil, then changes direction when it encounters the bedrock surface, accumulating as the bedrock funnels downward. Does this create underground streams that erode smaller particles and then leave open cavities during dry periods. I am imagining a layer with a greater volume of water (due to the filling of these cavities and the force of gravity) that typically moves faster next to the bedrock layer than at the surface. I imagine this layer as lubrication between the bedrock and the less liquefied surface layer, almost like pressurized liquid layer where a heavy snowfall liquifies enough that the snow on a sloped roof loses it's grip and slides off a roof in one big chunk. If this is true of a debris slide the leading edge not only carries the force of the liquifed debris behind it but also the less liquefied lateral material. So as the leading edge has comparative friction stability across its surface, it might hit the vertical tree trunks like a sheet of steel floating on top of the moving debris. Did you see any trees cut through the trunks, or were all the trees uprooted?
I get the impression that trees get “chopped” but also are entrained as the material they are growing in liquefies when loaded. the soils in slope areas like one here are incredibly variable, and there may be some removal of fines at depth…I really don’t know. we do see a good bit of initial sliding essentially removing soil at the bedrock boundary, so there is a zone of frictional failure there. as for what goes on between flow head and tail, it might depend on composition and distribution of particle size.
Unrelated question if I may…I saw an aerial pic of Kuwohi the other day and it looked like it had a couple of areas of slide off to the south west of the observation tower. I tried to search for lidar images of that, but couldn’t find any images. Just thought it was neat that I feel like I’m picking up on things like that partly due to your videos!
Yes, that is neat! Plenty of instability in the Smokies. There should be lidar on the National Map. If that landscape caught a Helene-type impact, it would go wild. The accumulated "fans" of debris there (like shown in this video) are incredibly huge.
The Bob Ross of geology is back :) Quick question: has there been any evidence of bedrock landslides being accelerated or caused by this event or these kind of events? Basically a number of smaller landslides/mudslides together causing slope toe erosion and eventually bedrock landslides after the event? Just thinking of other issues with unstable slopes we wouldn’t ordinarily associate with weather events. I assume new uphill facing scarps seen in post-Helene lidar imagery might show this assuming the bedrock in the blue ridge mountains is right. I only did geography at uni, and sadly didn’t focus as much as I should have with geology :)
this one definitely drifted in the Bob Ross direction… we have seen a few deeper seated, intact slides of weathered bedrock. I’m sure plenty of similar slides moved just a bit. I think one that developed during the storm just moved again after a few inches of rain. in short, yes, they’re out there, but they are tougher to see remotely. we have to wait for new LiDAR…
Outstanding explanation. The LIDAR image looks like the pattern of the land is a self-consistent pile in the lower area. If you drilled down through the lower slope, would you find a layered structure that showed previous events of a similar nature?
This may seem like a silly question, but my intro to geology class was many moons ago.... Do many of the larger rocks break into smaller pieces as they are flowing down hill, or is there enough liquid between them to keep them fairly intact? I mean I could see all the mica and such in the remains of silting from flooding in Cane Creek by Fairview. I know there is a lot of sand sized stuff in there when it is all held together, but does the event break rock down in a substantial way? Thanks for all the great info! It makes me want to take my retired self back to school and get that masters in geography....
stuff undoubtedly breaks down, but doesn’t have to. I guess less breaking might make a flow stay mobile since the pieces bounce off each other and don’t lose energy? I’m not sure if down in the guts of the flow the high pore pressure “pads” impacts or not. mics is interesting…I think micros soils can be poor at draining. I have no doubt that the Craigtown flows were so big because the rock and soil are so full of mica there.
Dry long-runout slides are usually characterized as not being well explained by the potential energy of the material before the slide started. Are wet slides such as these more or less correlated to height of fall - ignoring degree of slope, friction, etc?
I would say no…some of the biggest ones in this storm were on less extreme slopes, in terms of relief. like many things in Appalachia, it seems that soil and rock type are the big controls. materials control pore pressure maintenance and dewatering, so if youve got stuff with collapsible voids that doesn’t drain well, you can get a huge, rapidly mobile flow without the crazy topography. likewise, a rowdy slope with draining materials will “freeze” flows on the slope as they dewater
Very informative! I am reminded of videos by Pierre-Emmanuel Zufferey of debris flows in the Swiss Illgraben Valley which show torrents of multi-ton boulders tearing down debris channels like they weigh nothing, even floating and bobbing in what looks like a conveyor of cement. Wild things can happen with just enough water!💦🪨
yep, Illgraben videos are the best to see the process. finer details, such as the nature of little particles I didn’t even draw, have a big impact on whether or not water can drain and drop pore pressure. Illgraben is cool to look at on Google Earth
I always get excited when I see a new one of your videos in my feed. Thank you for making these.
thank you
As a resident of the Western NC area and an engineer, I really appreciate your videos. Your ability to explain these concepts in layman's terms is very helpful for people to understand this geologic event we witnessed.
thank you. it is a work in progress! this one went a bit far into the technical side but I wanted to make it.
One of the things I've noticed about these devastating landslides, is the bigger ones start way up on a steeper and higher mountainside and bring a lot of debris, compared to smaller ones that might go over a road or something and are not as bad as landslides like Stoney Fork and other areas. I worry behind our house but it's not a steep and tall mountain, but Sugar Mountain is behind and above us with a lot of development. I know there has been a landslide next to where we live many years ago and why it worries me. I feel like I'm having a geography class every time I watch you and I thoroughly like it knowing I'm going to learn more every time. You are a great teacher and explainer!! Knowledge is everything!
thank you.
I can't click on these fast enough. Thanks Philip. Much appreciation from the Burke×Avery Co line. Well done.
Another incident that was in close proximity to the Black Mt Range.
Seems like in every direction from Mt Mitchell it was significantly worse than other places, as far as slides/flows.
Technically the Craggys I believe, but still really close
Dang. Nearly 1600-1700ft vertical drop in less than 1mile of distance. Wow. That is WILD
I love watching these videos and marrying the information on maps on some hiking apps I use.
These videos really help to make sense out of what I've been seeing over the last 2+months
These videos will also provide future generations with information as a historical reference.
We are all being educated for free, and should be very thankful. I know I am.
yes, the blacks really blew up. certainly some of the most concentrated debris flows during the storm
I used to work at a place that made a fine grained PVC plastic. Up in the bins it would pack to between hard packed snow and cement. Stick an air line in the right place to fluidize it and it would run out like water.
exactly the same process. I use glass sandblast beads to model fluidized stuff like this. you can pile up a cone of them and give a tap and it turns into a puddle of them
Great breakdown, as always, of some of the dynamics behind what was a very surreal day. I've always heard that streams are surface expressions of the water table. We had so much rain that day it felt like the water table was sitting 1-2 inches above ground level because that was how much flowing water was on every surface of the mountain. Until a couple hours after it stopped really raining things were very weird.
yep, about right. if the whole surface flowed, it means full saturation was reached and overland flow had begun. at that point, everything is straight runoff and floods the streams massively. it’s like the whole landscape is a parking lot at that point.
I live in a creek bottom at the base of a ridge and sheet flow like that is a regular thing after a couple inches of rain. Amazing and a little scary .
You create the most helpful videos! You explain these concepts so thoroughly and make it easy for those of us who are not experts to visualize. Your paint illustrations are clear and concise, even while showing difficult concepts. Thank you so much.
thank you! I do my best with it.
The combination of water, fine mineral particles, and old broken down organic material, makes for a big slip n slide.
indeed!
Plus…. Gravity
another great video. i love this channel
Glad you find the content helpful.
Thanks for the effective visuals and explanation of debris flows. They were very useful for me personally to understand the physical events that resulted in these flows. Well done. Look forward to more great content.
thank you. try to follow this one with a couple more. tough to try to illustrate debris flow workings but I will give it a shot!
Dude! I’m hooked on these videos!
right on. tell yo friends!
It rained so hard so fast so much, that it literally created mud slides...a geological disaster....
I went to Tim Burleson’s page and seen they’ve had more flooding. The creeks are full of sediment and just a little rain now is causing flooding again. So sad.
interesting to hear that. there will probably be a lengthy adjustment period
Another very good explanation. Everyone of your vids teases out and vastly adds to knowledge I learned in my ocean engineering and oceanography studies. I really enjoy these, thank you
glad they are worth a watch!
Never heard it explained this way. Very interesting and helps explain the behavior coming down the hill and once it comes to rest in the valleys. It sounds like it’s more or less due to waters inability to be compressed
essentially yes. an “over-pressure” scenario. sometimes the term “undrained loading” is used, meaning the load squeezes the water and it wants to escape but can’t
New @TheGeoModels video! Heck yeah!
Might try to get one on Friday too
That was great! That ol phrase: "You learn something new every day"... thanks for making it easier to actually understand what's going on! Love these videos and I did learn something new yet again! Love these videos 🙂
thank you. trying to get a other vid out Friday. I don’t like Wednesday for uploads but it worked out that way this time.
@TheGeoModels looking forward to it! Upload on any day! Big smiles all around as soon I see a post!
Merry Christmas Phillip 🎄🎅🏻🎄
same to you!
hollers are also the same in the midwest. there are alot of hollers in Illinois along the Mississippi and Illinois river valleys
If I ever want to buy a home in the mountains, I’ll call you to show me where the dangers are! 🤣. But really…now I know
It can be done
How would you classify this event......a hundred year.....a thousand year or ten thousand year event ? Your channel is one of my favorites...Thank you !
tough to do because those are really just ways to express likelihood of occurrence…you might get another in 10 years! I suppose I have thought that I don’t really see river flooding effects like this event in the landscape, which would suggest it was bigger than anything in a long time. that said, I might not know what to look for! more on this idea in next video…
@@TheGeoModels Sweet I thought I saw a saw at least one fairly young similar landslides on this moutain.
Whoop! love your videos!
Thank you for pointing out hollow 😊
as in hollow vs. holler? it’s a key distinction! got to make sure we are on the same page!
another epic sesh!
I was sweating a bit after this one
I Love your content.
thank you. tried to keep this one shorter but it wasn’t meant to be. hope the illustrations worked out well enough!
It was very well explained. I love a longer video. Thank you.@@TheGeoModels
Excellent, understandable explanation!
I was wondering if over time, rain water settles through the soil, then changes direction when it encounters the bedrock surface, accumulating as the bedrock funnels downward. Does this create underground streams that erode smaller particles and then leave open cavities during dry periods. I am imagining a layer with a greater volume of water (due to the filling of these cavities and the force of gravity) that typically moves faster next to the bedrock layer than at the surface. I imagine this layer as lubrication between the bedrock and the less liquefied surface layer, almost like pressurized liquid layer where a heavy snowfall liquifies enough that the snow on a sloped roof loses it's grip and slides off a roof in one big chunk. If this is true of a debris slide the leading edge not only carries the force of the liquifed debris behind it but also the less liquefied lateral material. So as the leading edge has comparative friction stability across its surface, it might hit the vertical tree trunks like a sheet of steel floating on top of the moving debris. Did you see any trees cut through the trunks, or were all the trees uprooted?
I get the impression that trees get “chopped” but also are entrained as the material they are growing in liquefies when loaded. the soils in slope areas like one here are incredibly variable, and there may be some removal of fines at depth…I really don’t know. we do see a good bit of initial sliding essentially removing soil at the bedrock boundary, so there is a zone of frictional failure there. as for what goes on between flow head and tail, it might depend on composition and distribution of particle size.
You forgot to mention…….Gravity.
Love the videos.
I suppose you are correct…glad you like the vids
@@TheGeoModels sorry. I couldn’t help that. When my daughter was in seventh grade her answer to her science teacher was always
“ because of gravity?”.
Unrelated question if I may…I saw an aerial pic of Kuwohi the other day and it looked like it had a couple of areas of slide off to the south west of the observation tower. I tried to search for lidar images of that, but couldn’t find any images. Just thought it was neat that I feel like I’m picking up on things like that partly due to your videos!
Yes, that is neat! Plenty of instability in the Smokies. There should be lidar on the National Map. If that landscape caught a Helene-type impact, it would go wild. The accumulated "fans" of debris there (like shown in this video) are incredibly huge.
@ it’s just a matter of time I suspect.
The before picture looks like landslides are not a new event for that mountain
very true
Incredible it cut that pasture in half….my God. I look forward to your videos 😊♥️
pasture is still there; just underneath a big slug of mud rocks and trees! glad to hear you look forward to these
Fascinating
it’s a crazy process
The Bob Ross of geology is back :)
Quick question: has there been any evidence of bedrock landslides being accelerated or caused by this event or these kind of events? Basically a number of smaller landslides/mudslides together causing slope toe erosion and eventually bedrock landslides after the event? Just thinking of other issues with unstable slopes we wouldn’t ordinarily associate with weather events. I assume new uphill facing scarps seen in post-Helene lidar imagery might show this assuming the bedrock in the blue ridge mountains is right. I only did geography at uni, and sadly didn’t focus as much as I should have with geology :)
this one definitely drifted in the Bob Ross direction…
we have seen a few deeper seated, intact slides of weathered bedrock. I’m sure plenty of similar slides moved just a bit. I think one that developed during the storm just moved again after a few inches of rain. in short, yes, they’re out there, but they are tougher to see remotely. we have to wait for new LiDAR…
Outstanding explanation. The LIDAR image looks like the pattern of the land is a self-consistent pile in the lower area. If you drilled down through the lower slope, would you find a layered structure that showed previous events of a similar nature?
most definitely. a trench through it would be fascinating…and a bit frightening!
I could’ve told you yes… But I have watched these videos.
This may seem like a silly question, but my intro to geology class was many moons ago.... Do many of the larger rocks break into smaller pieces as they are flowing down hill, or is there enough liquid between them to keep them fairly intact? I mean I could see all the mica and such in the remains of silting from flooding in Cane Creek by Fairview. I know there is a lot of sand sized stuff in there when it is all held together, but does the event break rock down in a substantial way? Thanks for all the great info! It makes me want to take my retired self back to school and get that masters in geography....
stuff undoubtedly breaks down, but doesn’t have to. I guess less breaking might make a flow stay mobile since the pieces bounce off each other and don’t lose energy? I’m not sure if down in the guts of the flow the high pore pressure “pads” impacts or not. mics is interesting…I think micros soils can be poor at draining. I have no doubt that the Craigtown flows were so big because the rock and soil are so full of mica there.
Dry long-runout slides are usually characterized as not being well explained by the potential energy of the material before the slide started. Are wet slides such as these more or less correlated to height of fall - ignoring degree of slope, friction, etc?
I would say no…some of the biggest ones in this storm were on less extreme slopes, in terms of relief. like many things in Appalachia, it seems that soil and rock type are the big controls. materials control pore pressure maintenance and dewatering, so if youve got stuff with collapsible voids that doesn’t drain well, you can get a huge, rapidly mobile flow without the crazy topography. likewise, a rowdy slope with draining materials will “freeze” flows on the slope as they dewater
I ❤ Geology. Thank you!
glad you found it worthy!
Truly shocking and horrible and outright unnatural in its extent
that Hillside is hollow. Go to the top of the slide with a thermal camera. You should be able to find your way in.
should just be a big jumbled rock pile!
if im not mistaken. water cant be compressed. so not to far fetched.
😊
I love this channel.
right on!
mountains melt/ valleys split/ like wax next to a fire, pours down like water Micah 1:3-4
it was indeed this way
Very informative! I am reminded of videos by Pierre-Emmanuel Zufferey of debris flows in the Swiss Illgraben Valley which show torrents of multi-ton boulders tearing down debris channels like they weigh nothing, even floating and bobbing in what looks like a conveyor of cement. Wild things can happen with just enough water!💦🪨
yep, Illgraben videos are the best to see the process. finer details, such as the nature of little particles I didn’t even draw, have a big impact on whether or not water can drain and drop pore pressure. Illgraben is cool to look at on Google Earth
And gravity