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Earth Science

Oso Disaster Had Its Roots In Earlier Landslides 64

vinces99 writes: The disastrous March 22 landslide that killed 43 people in the rural Washington state community of Oso involved the "remobilization" of a 2006 landslide on the same hillside, a new federally sponsored geological study concludes. The research indicates the landslide, the deadliest in U.S. history, happened in two major stages. The first stage remobilized the 2006 slide, including part of an adjacent forested slope from an ancient slide, and was made up largely or entirely of deposits from previous landslides. The first stage ultimately moved more than six-tenths of a mile across the north fork of the Stillaguamish River and caused nearly all the destruction in the Steelhead Haven neighborhood. The second stage started several minutes later and consisted of ancient landslide and glacial deposits. That material moved into the space vacated by the first stage and moved rapidly until it reached the trailing edge of the first stage, the study found. "Perhaps the most striking finding is that, while the Oso landslide was a rare geologic occurrence, it was not extraordinary," said Joseph Wartman, a University of Washington associate professor of civil and environmental engineering and a team leader for the study.
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Oso Disaster Had Its Roots In Earlier Landslides

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  • OSO (Score:2, Funny)

    It's a bear. What comes around, goes around.
    • When I was little toddler I was fascinated by an hourglass --- particularly on the almost hidden but still perceivable pattern of a new slide happened on the back of an ancient slide

      Many things that we observe, even from something as tiny as the sandslides inside an hourglass, can be magnified many folds, and still hold true

    • Re:OSO (Score:4, Interesting)

      by CauseBy ( 3029989 ) on Wednesday July 23, 2014 @12:35PM (#47516759)

      The real problem was that libertarians fought hard and demanded the right to die in a landslide, and then they won that right. Famously kooky Richard A. Epstein and his political brethren demanded that big government bureaucrats stay out of his business when they tried to tell him that he lived underneath an inevitable landslide. He went to political meetings and courtrooms angrily demanding his right to live and die however he wanted. He got his way. I personally have zero sympathy for them. They were asshats who wouldn't accept good advice when it was given to them. They deserve to become lessons to the rest of us.

      I also reject the suggest that his hard-fought freedom made his life better. No, it didn't He could have lived equally well a quarter mile down the road where the rest of us wouldn't have to pay a bunch of money and do a bunch of work dealing with the disaster that befell him. It could have been a landslide onto an unoccupied hillside, but no, because of that jackass and his jackass friends we all have to deal with it as a human tragedy.

      Screw them. They don't like it when we tell them not to live under disaster-prone hillsides? Well I don't like it when I have to clean up his postmortem mess. Preventing this mess is why we tried so many times to tell him not to live there in the first place.

  • by sociocapitalist ( 2471722 ) on Wednesday July 23, 2014 @02:01AM (#47513559)

    To summarize the summary: "The most striking finding is that...it was not extraordinary."

    Not to belittle the loss of those involved but it's always a bit much that 43 dead in the US = catastrophe. If this had happened in Asia or Africa it wouldn't make the news unless hundreds or thousands had been killed.

    • I reckon 43 being killed in a short period of time by a single natural occurrence would make someone's local news. It's just that their local news wouldn't make Slashdot. I also think - not to belittle the ability of those Asians or Africans you mention to keep their people from dying - that when more than twenty people dying in a short period of time from the same cause happens fewer than twenty times a year in their country, then those happenings will be highlighted as catastrophes in their national new
    • by camg188 ( 932324 )
      I wonder how much news coverage that landslide got in Asia or Africa? If it happens somewhere else it's bad, if it happens in your backyard it's a catastrophe.
      • I wonder how much news coverage that landslide got in Asia or Africa? If it happens somewhere else it's bad, if it happens in your backyard it's a catastrophe.

        Another way to say that is that Americans tend to only care what happens in the US, for the most part, thus increasing the relative importance of what happens in the US versus what happens elsewhere in the world.

    • by paiute ( 550198 )

      To summarize the summary: "The most striking finding is that...it was not extraordinary."

      Not to belittle the loss of those involved but it's always a bit much that 43 dead in the US = catastrophe. If this had happened in Asia or Africa it wouldn't make the news unless hundreds or thousands had been killed.

      You are assuming that the Oso slide made the Asian and African news outlets.

      • To summarize the summary: "The most striking finding is that...it was not extraordinary."

        Not to belittle the loss of those involved but it's always a bit much that 43 dead in the US = catastrophe. If this had happened in Asia or Africa it wouldn't make the news unless hundreds or thousands had been killed.

        You are assuming that the Oso slide made the Asian and African news outlets.

        No I am not and I don't see how you arrived at your conclusion -

      • Ignore my previous post - I see you were answering someone else

    • Re:eh? (Score:4, Insightful)

      by Dutch Gun ( 899105 ) on Wednesday July 23, 2014 @07:00AM (#47514415)

      To summarize the summary: "The most striking finding is that...it was not extraordinary."

      Not to belittle the loss of those involved but it's always a bit much that 43 dead in the US = catastrophe. If this had happened in Asia or Africa it wouldn't make the news unless hundreds or thousands had been killed.

      Who cares what it's called? No one I know of is trying to compare this to the horrific losses in Japan after the tsunami, or other major disasters around the world. It was a big deal to us here in WA state (and I heard the terms "disaster" and "tragedy" used more often anyhow). An entire square mile of mud 10 to 40 feet thick wiped entire families and/or all their property from the face of the earth in an instance. Whatever you want to call it, it was pretty awful for everyone involved - including the rescuers.

      If my next-door neighbor gets robbed or had their house burned down, that would be a big deal to our local little neighborhood. Someone in the next town over might sympathize, if they heard about it at all. It wouldn't get reported on the other side of the country. That's just the reality of life, and it's nothing to wring our hands over.

      • by Nethead ( 1563 )

        Well said.

        -Joe from Tulalip

      • To summarize the summary: "The most striking finding is that...it was not extraordinary."

        Not to belittle the loss of those involved but it's always a bit much that 43 dead in the US = catastrophe. If this had happened in Asia or Africa it wouldn't make the news unless hundreds or thousands had been killed.

        Who cares what it's called? No one I know of is trying to compare this to the horrific losses in Japan after the tsunami, or other major disasters around the world. It was a big deal to us here in WA state (and I heard the terms "disaster" and "tragedy" used more often anyhow). An entire square mile of mud 10 to 40 feet thick wiped entire families and/or all their property from the face of the earth in an instance. Whatever you want to call it, it was pretty awful for everyone involved - including the rescuers.

        If my next-door neighbor gets robbed or had their house burned down, that would be a big deal to our local little neighborhood. Someone in the next town over might sympathize, if they heard about it at all. It wouldn't get reported on the other side of the country. That's just the reality of life, and it's nothing to wring our hands over.

        I'm in France and I'm reading about it on slashdot so it has actually made the news more or less globally.

        It has nothing to do with sympathizing. I sympathize with the family of those involved.

        The point that I was trying to make is that if the same thing happened outside the US then it almost certainly wouldn't make the news in the US at all, never mind being called a catastrophe.

        And yes, the word matters because of the scope that it implies.

  • by thephydes ( 727739 ) on Wednesday July 23, 2014 @04:06AM (#47513893)
    I don't live there, but looking at some of the photos, is deforestation potentially part of the problem? Honest question for which I expect to be flamed by some.... but there it is.
    • Re:a question.... (Score:5, Insightful)

      by penix1 ( 722987 ) on Wednesday July 23, 2014 @04:44AM (#47513991) Homepage

      No. Deforestation is not the problem. The problem is the entire area is a natural slide area because of the soil type. People encroached on that slide area and expected it to be stable (much the same as they encroach on floodplains and barrier islands and wetlands).

      No, what "caused" the loss of life more than anything was people moving into a high risk area.

      • +1 if I had it. So often you hear about these "catastrophes" when it's people moving into dangerous areas. Like people on the East Coast and hurricanes.

        These folks didn't "expect" the slide to be stable, they "hoped" it would be.

        • Re:a question.... (Score:5, Insightful)

          by timeOday ( 582209 ) on Wednesday July 23, 2014 @10:30AM (#47515815)
          What is the solution? Other than allowing insurance companies to price such considerations into their policies, I don't see one. Simply zoning the land into oblivion by law is too crude, given that many places come with risks to varying degree. Money is practically the only way to get people to think quantitatively, and insurance companies have the resources to factor in things like environmental studies whereas individuals do not.
          • by afidel ( 530433 )

            Actually the group worst hit WAS in an area where they weren't supposed to be, but they had the attitude of damn gubmint can't tell me what to do. source [nbcnews.com] (among many). If you think these folks would have been worried about higher insurance rates you're almost as loony as they are =)

            • But that's just it. If the government says "you can't live there," people rebel. But if a sign saying "Private Property - No Trespassing" bars the same people from even setting foot there, and they are priced out of buying their own property there because it is too expensive, that they have no problem with, since it's just economic forces at work, which are presumably infallible or for that matter unstoppable.
          • by penix1 ( 722987 )

            What is the solution? Other than allowing insurance companies to price such considerations into their policies, I don't see one.

            You seem to be eliminating the most powerful tool in the box. The insurance should reflect the risk. Another tool is requiring FULL disclosure by realtors trying to sell such a structure. Lastly, build sensibly taking the risk into account. If you are building into a flood zone, require the structure to be elevated above the base flood elevation. If you are building in known hurric

    • I don't live there, but looking at some of the photos, is deforestation potentially part of the problem?

      Yes. Don't listen to the sibling comment, which ignores the well-known fact that deforestation in fact was a contributing factor. Of course, if you actually wanted to know the answer to your question, you would have found it with google, dozens of times over.

    • by Smask ( 665604 )
      Deforestation helps, but the main cause here are "Glacial deposits" + rain, because I suspect those areas were under the sea level during the last ice age. Clay deposits made in seawater is called "quick clay" when the salt is filtered away.
      • by Rei ( 128717 )

        The 'pedia says that it's an ancient delta of glacial sand that was subsequently exposed to a lot of water flow, washing out the silt and clay, leaving just the loose sand and gravel with nothing to cement it together.

        • Trees reduce the water flows. It's not the anchoring depth of the roots that matters, but the water retained by the large trees.

          • by Rei ( 128717 )

            Are trees supposed to eliminate the river at the bottom that's been eating away at the foundation of the slope?

            • No, I don't think you have the physics right. Water flowing into the hill from the top down causes the slide. The river is far enough away from the cliff that your scenario doesn't happen.

              • by Rei ( 128717 )

                That's not what everything I've read about the disaster has said. The mountain has gone through cycles - whenever it collapses, the river gets moved away, and the slides stop for a time, but eventually it wears away the footings enough that it falls again. They'd even tried to prevent landslides there by manually shoring up the base back in the 1960s, but it just flowed over their reinforcements.

                The waterlogging of the soil is also a necessary factor too, mind you - not saying otherwise. :)

                • I've been in that area. The river is far enough away from the sides of the valley that it isn't eroding the slope. In my observational opinion. The river went through flat land, at least several hundred yards away from the valley wall.

      • I seriously doubt those areas were under sea level during the last ice age. Sea level was several hundred feet lower at the time. But glacial deposits + rain is a good enough reason for the slide to have occurred.

  • ... are going to collapse if surverys of old slides are made easily available.

    It's possible to map ground contours using SAR [wikipedia.org] through vegetation. And it would be trivially easy to make property purchases conditional on a risk assesment of landslide conditions basd upon past slide activity. There goes the market for those cheap riverfront vacation properties.

    • by nolife ( 233813 )

      There goes the market for those cheap riverfront vacation properties.

      There is a very good reason that some river front property is very cheap.

  • by B33rNinj4 ( 666756 ) on Wednesday July 23, 2014 @12:09PM (#47516545) Homepage Journal
    I really like how instead of intelligent discourse about the triggers for the landslide and any possible ways to prevent/predict future landslides, people latch on to one phrase, and use it to belittle the media or other political stances. It's like those Christian right-wing people obsessively throwing the word "hypothesis" around to justify their idiotic creationist beliefs. Was it a tragedy? Yes. Was it a disaster? Yes. Is that was this discussion is about? No. Please take it somewhere else, so we can continue to discussion.

"The whole problem with the world is that fools and fanatics are always so certain of themselves, but wiser people so full of doubts." -- Bertrand Russell

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