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NASA Earth Science

NASA Discovers Mantle Plume That's Melting Antarctica From Below (newsweek.com) 242

schwit1 shares a report from Newsweek: Researchers at NASA have discovered a huge upwelling of hot rock under Marie Byrd Land, which lies between the Ross Ice Shelf and the Ross Sea, is creating vast lakes and rivers under the ice sheet. The presence of a huge mantle plume could explain why the region is so unstable today, and why it collapsed so quickly at the end of the last Ice Age, 11,000 years ago. Mantle plumes are thought to be part of the plumbing systems that brings hot material up from Earth's interior. Once it gets through the mantle, it spreads out under the crust, providing magma for volcanic eruptions. The area above a plume is known as a hotspot.

[I]n a study published in the Journal of Geophysical Research: Solid Earth, Seroussi and colleagues looked at one of the most well studied magma plumes on Earth -- the Yellowstone hotspot. The team developed a mantle plume model to look at how much geothermal heat would be needed to explain what is seen at Marie Byrd Land. They then used the Ice Sheet System Model (ISSM), which shows the physics of ice sheets, to look at the natural sources of heating and heat transport. This model enabled researchers to place "powerful constraint" on how much melt rate was allowable, meaning they could test out different scenarios of how much heat was being produced deep beneath the ice. Their findings showed that generally, the energy being generated by the mantle plume is no more than 150 milliwatts per square meter -- any more would result in too much melting. The heat generated under Yellowstone National Park, on average, is 200 milliwatts per square meter.

NASA Discovers Mantle Plume That's Melting Antarctica From Below

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  • by NotQuiteReal ( 608241 ) on Saturday November 11, 2017 @02:24AM (#55529863) Journal
    Until a gamma-ray burst or a wandering black hole takes us ALL out. Or maybe just a stay rock or "lone-wolf" terrorist messes up your day.
    • Until a gamma-ray burst or a wandering black hole takes us ALL out.

      What would the effect of a really strong gamma-ray burst be? I mean, I know generally we'd have a bad time, but how quickly would it strike, and what would it be like? Would there be time to point to the skies, cry out "Good lord! (choke!)"?

      • Re: (Score:2, Informative)

        What would the effect of a really strong gamma-ray burst be?

        Bad. Really bad. They are the strongest electromagnetic events known to occur in the Universe. A big one can sterilize an entire galaxy. They are most likely to occur in the center of galaxies, which may explain why all known life bearing planetary systems are in the galactic fringes (disclaimer: data is limited).

        Would there be time to point to the skies, cry out "Good lord! (choke!)"?

        Unlikely. The initial burst can peak in 10ms.

        Gamma-ray bursts [wikipedia.org]

        • They would not sterilize the galaxy.
          They only would kill life on the side of the planet facing the burst.
          Hence half of the landmass and most of the water life will be unharmed.

          On top of that: a gamma burst will basically escape along the rotation axis of the object that is emitting it. Which is an extremely small beam.

          • Well I guess if you're happy with breathing nitrogen oxides, you'll be fine.
          • Gamma ray bursts typically have a beam angle between 3 and 20 degrees [universetoday.com]. Two beams are formed, opposite to each other, likely from the poles of the object that causes the burst. There are different types, the longer more powerful ones can convert up to a few suns worth of mass to energy in a handful of seconds. Smaller, more common, ones usually only convert about one thousandth as much. The effect on earth depends on the intensity, you would need to be within a few tens of light years and take a direct
      • by Narcocide ( 102829 ) on Saturday November 11, 2017 @04:33AM (#55530045) Homepage

        Try to imagine all life as you know it stopping instantaneously and every molecule in your body exploding at the speed of light.

        • by eddeye ( 85134 )

          Try to imagine all life as you know it stopping instantaneously and every molecule in your body exploding at the speed of light.

          Whew. That doesn't sound so bad. For a minute there I was worried...

        • Total protonic reversal.
          Right. That's bad. Okay. All right. Important safety tip. Thanks, Egon.

          God I miss being 12.
    • by Megane ( 129182 )
      Don't forget about Yellowstone. That and the "stray rock" are much more likely than a GRB or a random black hole. At least I'll be a safe distance away when New Madrid flips, if all those Oklahoma earthquakes are releasing its energy.
  • by 93 Escort Wagon ( 326346 ) on Saturday November 11, 2017 @02:32AM (#55529879)

    ... but I’m not sure what’s going on with the idiots posting further up in this discussion.

    In addition to Yellowstone, there’s the plume responsible for the Hawaiian Islands. Interestingly, as the tectonic plate shifts, the plume remains more or less in the same place below it. Currently it’s under the Big Island (obviously); you can see the direction that the plate is moving by looking at the chain of islands.

    • by ShanghaiBill ( 739463 ) on Saturday November 11, 2017 @04:28AM (#55530037)

      Currently it’s under the Big Island (obviously)

      Actually, it is under Lo'ihi [wikipedia.org].

      you can see the direction that the plate is moving by looking at the chain of islands.

      Kure is the last island in the chain, and is the northernmost coral atoll in the world. Beyond that there is a chain of seamounts [wikipedia.org] that have eroded below sea level. The last is more than 80 million years old, and is on the edge of the Kuril-Kamchatka Trench, a subduction zone near Russia. It is likely that even earlier seamounts once existed, but they have been subducted back into the mantle.

      • but they have been subducted back into the mantle.

        Would that be "basalt to basalt, crust to crust"?

    • ... but I’m not sure what’s going on with the idiots posting further up in this discussion.

      Wow, have I, idiot been summoned?

      I never bought the "Iron Sky" story about Nazis fleeing the second world war to set up a base on the dark side of the moon. However, the Germans did have a fetish for U-Boots, so them setting up a secret base on Antarctica would not be implausible. The heat under the ice in Antarctica could be coming from the secret Nazi base.

      Them warming up their Sauerkraut could explain the plume.

      Sauerkraut is rich in vitamin C, and was discovered by Captain Cook to cure scurvy.

      In addition to Yellowstone, there’s the plume responsible for the Hawaiian Islands.

      Yeah,

      • ... but I'm not sure what's going on with the idiots posting further up in this discussion.

        Wow, have I, idiot been summoned?

        No. I think *I* was being summoned...

    • by mysticgoat ( 582871 ) on Saturday November 11, 2017 @10:48AM (#55530837) Homepage Journal

      It has taken way too long to scroll down to this first on-topic post. But correcting the moderator system to limit the damage by paid trolls is another topic.

      I have a serious question about the Antarctic mantle plume(s):

      The Erebus plume under Ross Island has been documented ever since the International Geophysical Year (IGY) of 1957 and probably earlier. So has a second plume been discovered in the same area? Or is this story about confirmation of what was already known? WTF?

      Hopefully answers to this question will not get drowned by the paid trolls (and what I suspect may be paid troll fighters who keep the sewer floodgates open).

      • The Erebus plume under Ross Island has been documented ever since the International Geophysical Year (IGY) of 1957 and probably earlier. So has a second plume been discovered in the same area? Or is this story about confirmation of what was already known? WTF?

        Mantle plumes are a lot bigger than one volcano. For example, the Canary Islands (20-odd volcanic islands scattered over several hundred kilometres from the African coast) are the products of one plume.

        Erebus is on the other side of the Ross Ice Shelf

  • Just curious how this may change the current thoughts on climate change impact on artic ice. TFA is pretty quiet about climate science. Perhaps theyâ(TM)re just scrambling?

"And do you think (fop that I am) that I could be the Scarlet Pumpernickel?" -- Looney Tunes, The Scarlet Pumpernickel (1950, Chuck Jones)

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