Announcement

Collapse
No announcement yet.

America's oldest ice discovered... then it melts

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • America's oldest ice discovered... then it melts

    And yes Canada is in America.

    Seen emerging from a mud cliff, the smooth, near-black surfaces look like a long-lost objects from some high-tech civilisation. In fact, they are huge chunks of ice – the oldest ice ever found in North America.

    More than 750,000 years old, the wedges have survived through times when the planet was even warmer than it is today. Duane Froese of the University of Alberta in Canada and colleagues say their discovery could us predict the fate of the deep Arctic permafrost and its frozen methane stores.

    Ice wedges form when spring melt-water runs into fissures and freezes. Thermal expansion widens the cracks and allows the wedge to grow, up to around 3 metres wide and 6 metres deep.

    The team discovered the ancient ice several years ago at Dominion Creek – a site in the Canadian Yukon, just east of the Alaskan border. It had been exposed by mining activities in the area. They were able to date it thanks to a layer of ancient volcanic ash that had been deposited a few dozen centimetres above its top margin. The ash was about 740,000 years old, making the ice the oldest known in North America.

    "Much of the relic ice in the region dates to the last 100,000 years and most to the last 25,000 years," says Froese.
    Carbon store

    Remarkably, this means the Dominion Creek ice wedges must have survived two interglacial ages: 120,000 and 400,000 years ago. Computer models estimate that temperatures at the time rose to between 2 °C and 3 °C higher than the average today, which to Froese "illustrates how stubborn permafrost can be in the face of climate warming".

    Permafrost is ground that remains frozen all year round. This arrests the decay of vegetation, preventing the carbon which it contains from being released into the atmosphere as greenhouse gases.

    But Froese's findings do not mean that the Arctic permafrost, including the huge stores that cover much of Siberia, will survive the few degrees of warming predicted for the end of this century.

    For starters, Andrew Slater of the University of Colorado points out that although they are surrounded by permafrost, the ice wedges themselves are very different. "A block of solid ice like this wedge takes considerably more energy to thaw than a mixture of soil, ice and organic matter," he says.
    Try http://wordforge.net/index.php for discussion and debate.

  • #2
    Remarkably, this means the Dominion Creek ice wedges must have survived two interglacial ages: 120,000 and 400,000 years ago. Computer models estimate that temperatures at the time rose to between 2 °C and 3 °C higher than the average today, which to Froese "illustrates how stubborn permafrost can be in the face of climate warming".
    thats like 5 degrees F warmer... Alright, who was causing global warming back then?

    Comment


    • #3
      Originally posted by Berzerker


      thats like 5 degrees F warmer... Alright, who was causing global warming back then?
      You have heard of little things called ice ages right? A natural cooling? Global warming can be a natural phenomena too.

      But all models predict little to no warming due to natural causes this time around.
      Modern man calls walking more quickly in the same direction down the same road “change.”
      The world, in the last three hundred years, has not changed except in that sense.
      The simple suggestion of a true change scandalizes and terrifies modern man. -Nicolás Gómez Dávila

      Comment


      • #4
        Originally posted by Berzerker


        thats like 5 degrees F warmer... Alright, who was causing global warming back then?
        You always ignore this comment, so I will post it to you yet again to make you look foolish.

        Death is a natural process. That doesn't mean that there are no murders.

        Climate change is a natural process. That doesn't mean that the current climate change isn't cause by humans.

        Stop asking stupid questions.
        Christianity: The belief that a cosmic Jewish Zombie who was his own father can make you live forever if you symbolically eat his flesh and telepathically tell him you accept him as your master, so he can remove an evil force from your soul that is present in humanity because a rib-woman was convinced by a talking snake to eat from a magical tree...

        Comment


        • #5
          Originally posted by Comrade Snuggles
          Death is a natural process. That doesn't mean that there are no murders.

          Climate change is a natural process. That doesn't mean that the current climate change isn't cause by humans.

          Which explains the climate cooling of the middle four decades of this century, too. Oh, wait, it doesn't...
          (\__/) Save a bunny, eat more Smurf!
          (='.'=) Sponsored by the National Smurfmeat Council
          (")_(") Smurf, the original blue meat! © 1999, patent pending, ® and ™ (except that "Smurf" bit)

          Comment


          • #6
            Originally posted by Straybow
            Originally posted by Comrade Snuggles
            Death is a natural process. That doesn't mean that there are no murders.

            Climate change is a natural process. That doesn't mean that the current climate change isn't cause by humans.

            Which explains the climate cooling of the middle four decades of this century, too. Oh, wait, it doesn't...
            Modern man calls walking more quickly in the same direction down the same road “change.”
            The world, in the last three hundred years, has not changed except in that sense.
            The simple suggestion of a true change scandalizes and terrifies modern man. -Nicolás Gómez Dávila

            Comment

            Working...
            X