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Scientists Link Deep Wells To Deadly Spanish Quake

Posted by timothy on from the better-tell-those-guys-in-russia dept.

Meshach writes "Research has suggested that human activity triggered an earthquake in Spain that killed nine and injured over three hundred. Drilling deeper and deeper wells to water crops over the past 50 years were identified as the culprit by scientist who examined satellite images of the area. It was noted that even without the strain caused by water extraction, a quake would likely have occurred at some point in the area but the extra stress of pumping vast amounts of water from a nearby aquifer may have been enough to trigger a quake at that particular time and place."

14 of 118 comments (clear)

  1. Re:Span? by Hsien-Ko · · Score: 5, Funny

    In Euroe

  2. Re:Span? by The+MAZZTer · · Score: 5, Funny

    Inside of Body somewhere, which in turn is inside Html.

  3. Re:Span? by Jason+Levine · · Score: 5, Funny

    It's where the ran falls manly on the plan.

    --
    My sci-fi novel, Ghost Thief, is now available from Amazon.com.
  4. It's too complicated for me to understand ... by Taco+Cowboy · · Score: 5, Insightful

    From TPA:

    Research has suggested that human activity triggered an earthquake

    Umm ...

    It was noted that even without the strain caused by water extraction, a quake would likely have occurred at some point in the area

    Please pardon me, perhaps I am being too dense to understand the following intricacies:

    How can it be that "Human activity triggered an earthquake" when a quake "would likely have occurred at some point in the area" ?
     

    --
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    1. Re:It's too complicated for me to understand ... by R3d+M3rcury · · Score: 5, Interesting

      How can it be that "Human activity triggered an earthquake" when a quake "would likely have occurred at some point in the area" ?

      Imagine I pull out a gun and shoot you. Well, you would have died eventually anyway, right?

    2. Re:It's too complicated for me to understand ... by Anonymous Coward · · Score: 5, Insightful

      Translation: Humans cause it to happen *earlier* then it would have occurred naturally. They acted as the last triggering point rather then the natural stress buildup.

      Adding stress when stress is already slowly building up is the same as this example.

      A cup put underneath a running faucet. You adding extra water into the cup causing it to spill. That means that you caused it to spill, even if we know the cup would spill anyways due to the running faucet.

      As for if this was a bad thing or not, who knows. It's possible that the extra stress could have cause the earthquake to be weaker then it would have been if it just slowly buildup to even higher levels. It could have also make the quake stronger compared to say if it naturally just caused several quakes instead of 1 giant one. Since it didn't occur naturally, it's all what ifs at this point.

    3. Re:It's too complicated for me to understand ... by StormyWeather · · Score: 5, Interesting

      the interesting question is if triggering it sooner made it less severe or more severe.

    4. Re:It's too complicated for me to understand ... by Anubis+IV · · Score: 5, Interesting

      Eh, I'd prefer to use the analogy of pushing a boulder down a hill at his house, rather than waiting for erosion to do it a few years later. With a gun, you're changing how it happens and introducing all sorts of other complications. Even better, if we want to remove intent from the equation, maybe my house was next to the boulder and I left a hose running, which washed away the dirt under the boulder, leading to its cascading down the hillside into his house. While naturally-occurring erosion would've done the same job eventually, I just helped it along with some human-caused erosion.

    5. Re:It's too complicated for me to understand ... by Luckyo · · Score: 5, Interesting

      There is also a question of location. Drilling for water in populated area may have shifted epicenter of the quake closer to the population center in question.

    6. Re:It's too complicated for me to understand ... by Solandri · · Score: 5, Informative

      This one's a bit different from the quakes caused by fracking. In fracking, they just fracture the rocks and inject a fluid, basically lubricating the ground. There's almost no energy added to the system. So while the fracking may trigger a quake, it is not the root cause (all the energy released was already there). Any energy released from a fracking quake is energy which was already there.

      In this one they removed large quantities of water from the aquifer. While technically no energy was added to the system, the water's removal lowered the potential energy floor, essentially adding the potential energy of the now-too-high ground to any stress energy which had already been built up (if any).

      An analogue to this case would be sinkholes caused by extracting or receding water from underground aquifers/caves. The removal of the water itself directly causes the sinkhole, or in this case the quake. Depending on the quantity of water removed (and thus the distance the ground above had to "settle"), there might not even have been any natural fault slippage involved, and this quake could have been entirely manmade.

    7. Re:It's too complicated for me to understand ... by AmiMoJo · · Score: 5, Interesting

      Legally the only question is if this makes the people doing the drilling responsible for the damage caused by the earthquake. In previous cases involving things like erosion the answer has generally been "yes", even if the damage was inevitable.

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  5. Drilling deeper and deeper. by Z00L00K · · Score: 5, Insightful

    That also means that they are consuming more water than what is replenished each year, which in the long run may be a more important issue than a quake every 25 years or so.

    --
    If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
  6. Re:Span? by c0lo · · Score: 5, Funny

    Where the hell is Span?

    Relevant citation:

    The dwarves delved too greedily and too deep. You know what they awoke in the darkness of Khazad-dûm

    --
    Questions raise, answers kill. Raise questions to stay alive.
  7. Usually caused by adding water by Anonymous Coward · · Score: 5, Informative

    Human-induced earthquakes are usually caused by water injection, or more precisely by increasing pore fluid pressure which in turn has the effect of decreasing the rock's confining pressure. Basically, the water inside the rock pushes out in all directions with a (typically very high) pressure related to the height of the water column in hydrostatic communication with it above. The rock above is also pushing down, but other considerations aside, this confining pressure from the weight of the rocks tends to lock faults together preventing them from moving. The effective confining pressure is reduced by the pore fluid pressure pushing the rock apart. If you add to the water column the extra weight of the water may be minuscule compared to the increase in pressure caused by the greater height of the water column. That extra pore water pressure can then allow other forces, previously held in check by the rock's confining pressure, to break the fault causing an earthquake.

    The most common place for this to occur is in filling new reservoirs and in deep waste injection wells used for disposal of fluids from oil and gas production. Suck quakes are usually very small, but I think they've been observed in rare cases above magnitude 5.

    Removing water is a much less common cause of earthquakes. Pumping, for both water and oil, can ground subsidence, but rarely earthquakes. It will, however, subtly affect the balance of forces on a fault, so it's not inconceivable that it could cause a fault already near the breaking point to slip. I'd be curious to see the fault geometry and movement on the fault that caused the earthquake in Span.