Slo-mo landslide

By Phil Plait | June 4, 2011 7:00 am

An unusual amount of rain coupled with faster than average snow melt has triggered landslides throughout Canada and the United States. In western Wyoming, one came down on highway US 26-89 in Snake River Canyon. Days later, the landslide is still moving at about a half meter (18 inches) per hour, and the Wyoming Department of Transportation took an interesting time lapse video of it:

I had no real sense of how big or small this was until the guy ran in. It looks funny, but geez, there’s no way I’d stand on an active landslide, even if it were moving that slowly.

This makes me wonder if this might be another unforeseen consequence of climate change. Simply put, snow forms in storm systems when moisture gets carried upwards and freezes. More moisture means more snow can form. Warmer weather means more evaporation on the surface, so more moisture in clouds, and more snowfall. That’s how global warming can, seemingly paradoxically, mean more snowfall. Then, in the spring, when the weather warms up earlier and with higher temperatures, that snow will melt more rapidly, causing floods and landslides. Fun.

For more information, check out the American Geophysical Union’s blog post about the landslide.

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CATEGORIZED UNDER: Cool stuff, Pretty pictures

Comments (35)

  1. At what velocity does creep become a flow? Anyone know?

  2. Climate change will almost certainly impact a range of natural hazards but there’s a whole bunch of different variables in play. Depending on which way which variables go, the hazard could get worse, stay the same or fall. For example if climate change alters vegetation patterns forest fires could become less severe. If average rainfall drops then soils will be drier and more able to absorb water cancelling out increases in intense rainfall. The answer will probably be different depending on where you are.

    In any case landslides often have some human causes involved from leaky pipes, to carving up the hillside, to modifying the way water flows down a slope. And if we didn’t put buildings and infrastructure in places that are landslide prone then the chances of them causing any trouble would be slim.

  3. Nice Ogress

    @ Phils’ “There’s no way I’d stand on an active landslide…”

    Really, it’s just a matter of scale. Pretty much any time you’re on a mountain at all, the ground is moving. I still recall in my high school geology class, Mr. Houck (bless him) showed us a yearlong time-lapse of a ‘still’ mountainside. The boulders were prone to fast, sudden shifts, but even the dirt and pebbles moved – just not as quickly. I don’t remember the total average rate, now, but I remember it shocked me at the time. How could anything that wasn’t alive move so much?

  4. Google “Portuguese Bend” for a seriously slow landslide. One whole section of the Palos Verdes peninsula south of Los Angeles is slowly but surely sliding into the sea. The road around PV has to be constantly repaired. A time lapse video of that would be cool, but you’d have to film for years before really seeing anything.

  5. Old Muley

    Did anyone else have “Benny Hill” music playing in their heads when those guys ran out onto the landslide?

  6. idahogie

    This slide is about 45 minutes from me. I heard that it would be about 6 weeks before the road opens again (assuming it wasn’t damaged in the slide). Now I know why.

  7. Michel

    I ROTFLLOLD when that second guy came up from the other side.
    He just turned and ran for the hills!

    “even if it were moving that slowly.
    This makes me wonder if this might be another unforeseen consequence of climate change.”

    And to fight these slow moving slides we need to cut all trees.
    You can clearly see all kinda trees in the slide. Slowing it down.
    That Republican guy might be onto something…

  8. Jared

    It’s obvious, really. The trees started the landslide, and are using it to move around. They couldn’t get from A to B any other way, after all.

  9. Michel

    AH YES! *facepalm*
    I totally forgot about the weight of those trees and how they use it!
    You are musting be right!

  10. Chief

    I have to laugh and shake my head at those who say it is snowing more, thus it isn’t global warming, it is getting colder. Historically, I find that the winters that have the temperatures warmer (ie closer to the minus mark) will produce more snow. Very cold air will tend to produce dryer air and thus less snow. Just the power of observation and common sense with a bit of understanding of science thrown in. Nice to have phil back me up.

    Here in eastern Ontario, this spring was a wet one with large areas of standing water everywhere. It has finally started to dry enough for the fields dry out.

    I’ve never heard of a land slide moving this slowly for such a prolonged time. very interesting. almost like a lava field.

    What went through my mind is “Where’s Waldo….”

  11. RaginKagin

    Where I live, in the midwest, we just suffered from one of the longest, coldest and snowiest winters in history and were just warned that the snow north of us hasn’t melted yet and we’re still due for more flooding…which is very unusual this late in the year for us. I just turned on my AC this weekend, a full month later than last year, I also have a strict no heat after Feb rule that I was forced to break this year for fear of pipes freezing.

    I have no doubt climate change is happening, I am just of the opinion that it is always, and has always, been happening and we aren’t even beginning to know how or why. We’re as likely to change it as that guy is likely to stop that land slide.

    Just to add this in, the Republican asking about trees was a moron. As fiscally as I may be a Republican, and I am certainly against deforestation of any kind. I think America should stop worrying about expanding and start worrying about fixing what we’ve got. So…please don’t facepalm and think I’m a Republi-troll or something. It’s just an observation.

  12. Michel

    Global Warming can be a bit confusing.
    It´s all about humidity, winds, jetstreams getting more northern etc.
    But trust me. It´s getting warmer.

  13. Ray

    “This makes me wonder if this might be another unforeseen consequence of climate change. ”

    Yes, Phil, its global warming at it again.

    It has never before rained nor has snow ever melted in Wyoming.

  14. Tobin Dax

    I’ve got “Yakety Sax” running through my head after that.

  15. Michel
  16. HvP

    This is not a strict criticism of Phil’s conjecture, but a warning concerning perspective.

    Anyone who tries to use personal experience regarding local weather as anecdotal evidence for/against global climate change should consider this: The United States only constitutes less than two-percent (2%) of the Earth’s global surface area. The entire Americas, both North and South America combined, only account for 8.3% of the Earth’s total surface area.

    Global warming/climate-change means global, including both water, land, and atmosphere. Also, if we consider a roughly 100 year period of observation, then a data point consisting of the weather in the United States over a period of one year only amounts to 2% of 1/100th of the entire data collected on global climate change.

  17. Ken

    #10 (Chief): Google “Thistle landslide”. The Thistle slide (actually called a “slump”) normally moves much more slowly than the Snake River slide, generally on a scale measured in centimeters per year rather than meters per hour. The Thistle slump has been moving intermittently since prehistoric times and reduces the volume of Billie’s Mountain, located in Utah about 25 miles south of Provo. When stress builds up in the slump and the land acquires enough moisture, sudden larger movements occur.

    1983 saw a catastrophic failure of one side of the mountain, due to snowmelt. Enough earth moved to dam the Spanish Fork River and to bury both a rail line on which four railroads run (including Amtrak) and a duplexed US Highway 6/89:
    To date this incident remains the most costly landslide in U.S. history.

    The last major slump occurred in 1998 and was caused by snowmelt as well. I would wager that engineers are observing the Wasatch Range right now for increased motion in the slump.

    (Poor US Highway 89!)

  18. dcsohl

    Agreed. Global warming / climate change is a statistical phenomenon. Pointing at any single event and saying “aha!” is asking for denialists to come out of the woodwork. And they’d be right. After the 2005 hurricane season I was thinking global warming was here for sure, but it hasn’t even come close to being replicated. It was a statistical fluke… helped by climate change no doubt, but essentially a one-off.

    With that being the case, it is highly risky to point to a landslide and say, “I wonder if this is a consequence of global warming”. It is far too easy to dismiss it by saying “it has never rained or snowed before in Wyoming”.

    And yet… if it continues–and it will continue–we can certainly, safely, say that we should expect more of these events, without actually saying that any given one is due to climate change. It’s all about the statistics, and the core stat is the average–as in, the average number of these events will go up.

  19. John Carll

    Phil, Isn’t this more of a high speed landslide?
    Not really slow-mo at all.

    Still freakin’ neat. Scary too…

  20. Randy A.

    “Landslide” is a generic non-technical term for earth materials moving downhill under the influence of gravity.

    The landslide in the video clip looks like an earthflow. Earthflows can move at inches per hour, or slow down to inches per year, such as the Portuguese Bend earthflow mentioned by kuhnigget (#4).

    The speed of landslides varies from debris avalanches, which can go at over 200 kph, to soil creep, which might be only a couple centimeters per year.

    Phil, you said: “there’s no way I’d stand on an active landslide, even if it were moving that slowly.” Would you stand on a glacier (also moving)? At 0.5 meter per hour, you’d have little or no sense of movement. Just watch your step because the ground surface could have fissures and crevasses.

    And try to avoid debris avalanches. I’ve seen the deposits left by prehistoric debris avalanches. In one spot you can see granite boulders cut in half by the landslide…

  21. Jfefersonian

    Phil, this is in a high-landslide area due to the morphological makeup of the Snake River Range. This highway has had spring mudslide zones every since it was built. That’s why WyDot is able to respond as well as they do. Problem is, when the road’s closed, trucks can’t get into Jackson Hole and grocery shelves lapse (because trucks aren’t allowed the other way, over Teton Pass).

  22. JB of Brisbane

    That’s not a landslide, that’s a land-glacier. But it did bring to mind the line from “that Scottish play” – “Till great Birnam Wood doth come to Dunsinane…”

  23. I had no idea that the video was sped up until the guy came in. That is slow and hilarious. The weather this year has been ridiculous… it was horribly cold for longer than usual and then it jumped to this crazy hot storm world… I doubt it’s directly related to climate change since it wasn’t like this last year, but it might have some connection.

  24. Thing

    For comparison… here is some fast-motion land-slippage (well a washout anyway)

  25. Messier Tidy Upper

    @16. HvP : “Global warming/climate-change means global, including both water, land, and atmosphere.”

    Yep – and also changing weather patterns and more warming over the Arctic than elsewhere. This short clip from the always excellent Peter “Greenman3610” Sinclair shows what may be a factor here :

    While this one :

    gives the 2010 Arctic ice update direct from the field – or ocean as the case may be.

    Plus this one :

    Also from that “Climate Crocks” series debunks the idea that local cold weather somehow disproves the Global warming trend.

  26. Messier Tidy Upper
  27. Michel

    Explaining GLOBAL events to people who don´t look further then their backyard is an impossible mission.
    Pardon my french.

  28. Undeniable

    “This makes me wonder if this might be another unforeseen consequence of climate change. ”

    It is a consequence of weather.

  29. Messier Tidy Upper

    @ ^ Undeniable : So why do we get the weather we do? Why do we get snowfall in the Arctic and Antartica and so many days of endless sunshine and no rain in deserts?

    Answer is that we get the weather – the erratic and seasonal distribution of precipation, sunshine, cloud and storms within certain predictable limits – in whichever region we’re in because of that region’s climate.

    The climatologists – the expert climate scientists who have studied this area their whole lives are now telling us there’s a problem. That human emissions of Greenhouse gases are causing the climate to change, to get warmer, to move away from the conditions we’ve grown up with and become more extreme and severe, less predictable and to cause us problems.

    Do you choose to listen or do you choose to blame the messenger, to ignore the data that are indicating you have a problem? Up to you – but consequences flow from that choice.

    It’s like ignoring your medical doctor when he tells you to, say stop smoking or eating too much. Blaming the Doctor and rejecting his advice almost certainly won’t end well for you. You’ll end up sick – or even dead. When it could’ve been avoided.

    Same applies here – blaming the climatologists and rejecting their advice means that things for everyone will get worse. Much worse. Plus just like a medical issue, the sooner you stop the bad actions (eg. smoking, eating too much unhealthy food, emitting too much C02,) the better the state you’ll be in.

    The sooner we act the less severe the consequences are – the less people are likely to die and lose their homes and lose other things of great value. Such as whole islands and ecosystems. The later we leave it, the harder, the more costly, the more difficult it will get.

    Please look at the videos I linked in # 25. Look at the others in that series. Think about them – long & hard. I know the “climate contrarians” arguments against the scientific consensus the climatologists have long ago reached, blazes I used to be a climate contrararian myself once. They don’t stack up.

    @27. Michel : “Pardon my french.

    Well certainly, except I don’t see any Francais there at all! 😉

  30. Messier Tidy Upper

    @ Undeniable : Please look at all these :

    They’re easy to watch, entertaining and informative.

    Also look at this site :

    and this youtube series :

    Then please consider and reflect upon what you’ve seen there and what you’ve been saying.

  31. Messier Tidy Upper

    Also, please, see what NASA has to say here :

    and here :

    and what our host the Bad Astronomer said (& linked) on this very blog here :

    as well.

  32. Nigel Depledge

    Lindypenguin (2) said:

    If average rainfall drops then soils will be drier and more able to absorb water cancelling out increases in intense rainfall

    Soil that is very dry is not good at absorbing water rapidly. This is why deserts have flash floods when it rains for the first time in ages.

  33. Nigel Depledge

    RaginKagin (11) said:

    I have no doubt climate change is happening, I am just of the opinion that it is always, and has always, been happening and we aren’t even beginning to know how or why.

    What utter nonsense.

    Of course we know how and why climate change is occurring. At its heart is the basic thermodynamics of the absorption and re-radiation of IR in the atmosphere.

    We have also measured an increase in the rate at which global average temps are increasing.

    While GW has obviously occurred in the past (how else does an ice age end?), there is a huge difference between the various natural processes that can cause it and the process that is causing the current warming trend.

    We’re as likely to change it as that guy is likely to stop that land slide.

    With an attitude like this, do you ever achieve anything that is hard to do?

    No-one ever said that halting GW would be easy. People like you only make it harder for everyone. But halting GW is most certainly possible.

  34. Snaga

    I drove over this returning home from Jackson on Memorial Day. That is a massive chasm above the road left by the slide. We were quite amazed that the canyon was open again so soon. But as has been said, cutting off that canyon cuts off Jackson is some very real ways, and just as tourist season is starting. Its far from fixed, but open.

  35. Geomaniac

    I saw your post this morning and heard this on NPR this afternoon:
    Another slo-mo landslide all the way across the country. Weird-O-rama!

    This video looks very much like the motion of a glacier. I wonder how many of the same processes are at work here.

    Also the term ‘Global Warming’ is misleading because not only is the globe warming, but we are also experiencing ‘Climate Change’, which I think is a more accurate term. The globe is getting, hotter, colder, wetter, dryer, etc. depending on where one is on the planet.


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