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Antarctic Blast Made Australia, Room For Dinosaurs 122

Posted by Zonk from the uncomfortable-tourist-destination dept.
Agent Provocateur writes "Posted on the Science Daily site is a story from Ohio State University about a massive Antarctic blast that may have contributed to the Permian-Triassic extinction." From the article: "Its size and location -- in the Wilkes Land region of East Antarctica, south of Australia -- also suggest that it could have begun the breakup of the Gondwana supercontinent by creating the tectonic rift that pushed Australia northward. Scientists believe that the Permian-Triassic extinction paved the way for the dinosaurs to rise to prominence. The Wilkes Land crater is more than twice the size of the Chicxulub crater in the Yucatan peninsula, which marks the impact that may have ultimately killed the dinosaurs 65 million years ago. The Chicxulub meteor is thought to have been 6 miles wide, while the Wilkes Land meteor could have been up to 30 miles wide -- four or five times wider."
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Antarctic Blast Made Australia, Room For Dinosaurs More

Antarctic Blast Made Australia, Room For Dinosaurs

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  • This is what always gets me about those Hollywood disaster movies. The BBC calls this The Day the Earth Nearly Died [bbc.co.uk]. And yet, as we can see, it didn't. Somehow, The Day After Tomorrow seems kind of pathetic in comparison.
    • The fact that these disasters don't "kill the earth" is widely understood. Bacteria for instance can endure almost anything, and for the earth to be fysically destroyed, you would need a *very* big boulder. The problem is that more complex life does not take nearly as much abuse. So as long as you don't care about billions of people dying, if not extinction of the human race, then you can keep sleeping in total comfort. But for me that complex, self-aware life would have to start again would not be a comfor
      • "...for the earth to be fysically destroyed, you would need a *very* big boulder."

        Even bigger than you think. Current theory (speculation/whatever) says that the Earth-Moon system was created a few billion years ago when something the size of Mars smacked into the (pre) Earth. And it still wasn't destroyed - just changed a bit.

        Of course, if that happened now even the bacteria would be *severely* upset about it.

        Spelling Nazi alert: You mean "physically".
        • Even bigger than you think. Current theory (speculation/whatever) says that the Earth-Moon system was created a few billion years ago when something the size of Mars smacked into the (pre) Earth. And it still wasn't destroyed - just changed a bit.

          Of course, if that happened now even the bacteria would be *severely* upset about it.

          I for one would be slightly pissed as well.
          This is my home too.
          • "You can't destroy the Earth! That's where I keep all my stuff!!" - The Tick
            • The Mariner 10 mission to Mercury revealed a key data item that Earthly geophysicists need to pay more attention to.
              This is the Caloris Basin and, on the opposite side of Mercury, some very strange topography that is usually called "weird terrain".
              The explanation is the the shock waves from the impact that created Caloris converged on the opposite side of Mercury and tore the landscape to pieces.
              Well, Mercury is small and internally much cooler than Earth, so Mercury has a thick crust while the Earth's c
              • Thus the "Siberian Traps", which formed at about the same time as the Permian Extinction. All we need to solidify that speculation is to study the positions of the continents at that time (not where they have drifted to, today).
                I think the two areas were (approximately) at quadrature - 90 degrees apart, not in opposition.

                More evidence for this sort of Double Disaster comes from the Chixulub impact, which, when it happened, it is known that India was on the opposite side of the world, and the "Deccan Traps"
        • Of course, if that happened now even the bacteria would be *severely* upset about it

          That may be true, but the bacteria didn't pay for it, now did they?
        • Actually, an impact that size would actually 'kill the Earth', in the sense that it would likely sterilize the planet of all life. A Mars-sized impactor would recreate the magma ocean that covered the planet when it first formed. Bacteria are hardy, but none of them can live in molten rock.
        • > Of course, if that happened now even the bacteria would be *severely* upset about it.

          Forget the bacteria. It's the mice that would be absolutely FURIOUS about such a monumental cock-up.

          cya,
          john
        • You might enjoy this link about "geocide". [qntm.org] It's a HOWTO on how you can destroy the Earth.

          This is not a guide for wusses whose aim is merely to wipe out humanity. ... If total human genocide is your ultimate goal, you are reading the wrong document. There are far more efficient ways of doing this, many which are available and feasible RIGHT NOW. Nor is this a guide for those wanting to annihilate everything from single-celled life upwards, render Earth uninhabitable or simply conquer it. These are trivial go

        • alt.destroy-the-earth calculated that it takes on the order of 10^38 joules to shatter a world roughly the mass of Earth. A Mars-sized object could do it, if it was moving 110,000 km/sec, a significant fraction of lightspeed. (the above is a ballpark, i.e., should be accurate within one order of magnitude.)
      • The fact that these disasters don't "kill the earth" is widely understood.

        Perhaps true; on the other hand, the P-T extinction event wiped out better than 90% of sea species, and 70% of land species. It didn't kill the planet, but it came closer than anything since the formation of Luna.

        On the gripping hand, getting rid of the extremophile bacteria as well would pretty much requires re-liquification of the entire planetary crust for a multi-century timescale.

  • "...the Wilkes Land meteor could have been up to 30 miles wide..."

    Wow, I knew some dinosaurs were big, but I didn't realize they were that big!

  • Age of impact (Score:3, Insightful)

    by MichaelSmith ( 789609 ) on Saturday June 03, 2006 @03:24AM (#15460604) Homepage Journal

    They are guessing that it was in the last 250 million years because they can still detect a mass concentration. I wonder if it is possible to drill to the bottom of an ice cap and then drill into the underlying crust. Doing that may make it possible to accurately date the impact.

    Ice drills in my experience melt a hollow cylinder of ice and then extract the core. Presumably they would have to do this down to the surface and send a traditional drill down.

    • Re:Age of impact (Score:1, Funny)

      by Anonymous Coward
      It's far easier to wait for global warming to melt the ice cap, and then drill from there.

      1. Melt Ice caps.
      2. Do research.
      3. Profit!

    • Re:Age of impact (Score:3, Interesting)

      by arivanov ( 12034 )
      Indeed. The dating is completely arbitrary. All that we know is that it is not very old.

      It may in fact end up being simultaneous with Chicxulub which by most recent estimates was not enough in itself to kill of the dinosaurs. Something else helped it.

      So the "mummy dinosaur says to toddler dinosaur: what goes around comes around" joke will have to wait for now.

    • Re:Age of impact (Score:4, Interesting)

      by whathappenedtomonday ( 581634 ) on Saturday June 03, 2006 @07:01AM (#15460942) Journal
      I wonder if it is possible to drill to the bottom of an ice cap and then drill into the underlying crust.

      It's been done in the Arctic Ocean, Nature reported recently. [nature.com]

      "The results are unexpected. Not only did the Arctic heat up to an extent that is inexplicable by current climate models, say the researchers, it also seems that the North Pole began to cool at about the same time as the Antarctic. This timing suggests that climate was being driven by a global factor, such as atmospheric levels of greenhouse gases, rather than something more local, such as geological upheaval."

    • Drilling through ice is a difficult process with lot's of problems.
      One of the problems is that the ice is not lying still during the time that you are drilling, the ice creeps. That is once of the reasons why all the major drillings through ice are done on the top of the ice sheets where the movements are the least there.
      The problem with Ice creep is pretty big, it is for example not possible for scientist to come back to the hole's they drilled before, like you do with holes in the earth, the holes shut
      • Drilling through ice is a difficult process with lot's of problems.

        Its not easy, I agree. Glaciologists I used to work with would drill a hole then drop instruments down it to measure differences in ice flow at different depths. I am sure that eventually a hole would become unusable as shear forces moved it away from vertical.

        The RTG powered "mole" devices being planned for Europa might work in this environment. It would certainly be a good test, but developing something like that can take > 10 years.

  • How did the dinosaurs get here? It is my theory that they rode in on that meteor, bringing with them the advanced technologies that our government is still unearthing today (Al Gore "invented" the internet by digging it up from an ancient dinosaurian city). Also, "rawr" I'm a dinosaur.

    • Re:more importantly (Score:5, Funny)

      by orthogonal ( 588627 ) on Saturday June 03, 2006 @03:35AM (#15460624) Journal
      How did the dinosaurs get here? It is my theory that they rode in on that meteor, bringing with them the advanced technologies that our government is still unearthing today (Al Gore "invented" the internet by digging it up from an ancient dinosaurian city). Also, "rawr" I'm a dinosaur.

      Mr. President, shouldn't you be working on a plan to get us out of Iraq, rather than posting on slashdot?

  • Bullshit. (Score:4, Funny)

    by EvilCabbage ( 589836 ) on Saturday June 03, 2006 @03:32AM (#15460617) Homepage
    That's just what God wants you to think.

  • not as clear-cut as the article makes it out (Score:4, Interesting)

    by flyingsquid ( 813711 ) on Saturday June 03, 2006 @03:37AM (#15460630)
    At this point, it's pretty clear that the dinosaur extinction was caused by an asteroid/comet impact. First, they found an iridium signature suggesting an extraterrestrial object, then shocked quartz suggesting an impact, and finally the Chicxulub crater. Dating of the crater and the ash layer it has produced place them at the same time the dinosaurs (as well as many other animals, such as ammonites) go extinct.

    But the situation is much murkier with the Permian extinctions. Last I'd heard, we have yet to find clear evidence of an impact in the form of iridium, a dust layer or shocked quartz. So that sheds some doubt on the idea of an impact. Even if this is an impact crater, we don't know for certain that it dates to the time of the end-Permian mass extinctions: obviously, if it didn't occur at the same time as those extinctions, it couldn't have caused them. Given that the researchers are using radar and gravitometry, how do they know how old it is? You need to either do radiometric dating or look at the fossils to tell how old the underlying and overlying rocks are.

    There is also some evidence that the Permian extinctions may have been drawn out, with several bouts of extinction occurring over the course of a million years or so, again that doesn't fit with an meteorite/comet impact. Anyhow, it might have been an impact, and it might not have been. It's still a mystery and probably will be for quite a while.

    • But the situation is much murkier with the Permian extinctions. Last I'd heard, we have yet to find clear evidence of an impact in the form of iridium, a dust layer or shocked quartz.

      Xu and Yang, 1993 and Yang et al. 1995 have reported Iridium spikes and Stishovite microspherules in non-marine P/T sediments in Australia and Antarctica. There's no Permian oceanic crust left since all of it has been subducted, and the Iridium and Stishovite levels are an order of magnitude smaller than C/T sediments, but it is still evidence of some type of major impact.

      • On the other hand, Benton says they're full of shit with their impact evidence. But then, maybe Benton is full of shit when he says they're full of shit- not being an expert in impacts, I have no clue (he's who I'd been relying on for the bit about little evidence of impact, but after doing a bit of searching on Google Scholar he sounds like he may be standing alone out in left field on this one). There are a number of studies which date the Siberian Traps to the Permian-Triassic boundary. The Siberian trap
    • This article [bbc.co.uk] from the BBC was a little more in-depth.

    • At this point, it's pretty clear that the dinosaur extinction was caused by an asteroid/comet impact.

      No, it's not. It's pretty clear that there was a significant impact that coincided with the decline of the dinosaurs, but coincidence is not the same as causality.

      The asteroid did not cause the continents to continue their drift, widening the gap that would become the Atlantic Ocean. It did not cause the drainage of the shallow inland seas that enhanced a dinosaur-friendly climate. The asteroid did

      • What are the odds of this being a coincidence, however? Think about it. The extinction of the dinosaurs was one of the five largest mass extinctions of all time, an event which occurs on the order of once every hundred million years. The Chicxulub impact is the largest confirmed asteroid impact for the past 200 million years; again we're dealing with an event which occurs on the order of once every 100 million years. The odds that two such phenomenally rare events occurred simultaneously and had nothing to
        • Mad Americans keep finding T Rexes and the like [bbc.co.uk] with intact skin and flesh over their bones. That kind of puts the lie to a 60- or 70-million-year gap since their death, and it's not all.

          Toss in a few things like Coelacanth [wikipedia.org] and dinosaur ages start to get seriously murky. A friend of mine accidentally bought one of those in an Indonesian fish market, it was on the table with everything else and (apparently) often is, there.

          Then we have this new crash-bang which would be difficult to label a non-meteor, and b

  • Thank you mr meteor for making sure my home is toasty and warm.
  • The Chicxulub meteor is thought to have been 6 miles wide, while the Wilkes Land meteor could have been up to 30 miles wide -- four or five times wider.

    It bothers me that that calculation isn't quite as definate as it should be. I've yet to see 30/6 = 4.

  • Obligatory Anime Reference. (Score:5, Funny)

    by RoffleTheWaffle ( 916980 ) on Saturday June 03, 2006 @04:40AM (#15460745) Journal
    Well, I see that we've found Adam. Crap, now the world's going to end in the dumbest imaginable way and we're all going to melt.

    • Re:Obligatory Anime Reference. (Score:1, Funny)

      by Anonymous Coward
      Not if Asuka dodges that fucking pseudospear of longinus instead of looking at it charmed
      • Not if Asuka dodges that fucking pseudospear of longinus instead of looking at it charmed

        Never mind Asuka. She'd done her bit: chopped up all nine Mass Production Evas and run out of power. Nothing she could have done against a spear out of nowhere.

        Now Shinji, on the other hand... he finally gets into EVA-01, comes out of HQ in a massive explosion taking out the entire top of the pyramid - and proceeds to just stand there screaming. Doesn't lift a finger to even try to stop the Evas skewering him and in

    • They found the geo-front [yahoo.com] too. We're Doomed!

  • What did it kill to pave the way for the dinosaurs? Orcs? Oompah Loompahs?

    Do the chickens have large talons?
    Boy, I didn't understand a word you just said.

    • Ecological niches (Score:3, Insightful)

      by Flying pig ( 925874 )
      Conventional wisdom is that species evolve to fit particular ecological niches. It is difficult for another species to arise to fill that niche because the one already in it is well adapted to it, therefore a less well suited species will fail to take over - unless there is a change which leads to extinction of the current niche occupier or its becoming less fit. This applies to all sorts of things, even the population of bacteria in our intestines which will adjust to suit changes in diet, or as a result o
    • The Permo-Triassic mass extinction killed most of the so-called mammal-like reptiles (to be cladistically correct, they were actually reptile-like mammals), which were the dominant land herbivores and carnivores.
  • Finally! proof that Neon Genesis [wikipedia.org] Really happened! Now to figure out what happened to Rei

  • Thank you! (Score:5, Funny)

    by Alsee ( 515537 ) on Saturday June 03, 2006 @06:01AM (#15460871) Homepage
    The Chicxulub meteor is thought to have been 6 miles wide, while the Wilkes Land meteor could have been up to 30 miles wide -- four or five times wider.

    Thank you for for adding that! Saved us all the trouble of pulling out slide rules to work out that ugly divison problem ourselves!

    -
    • Maybe it was a question, I would hazard a guess and say...not 4 but 5 times wider!

      (seriously though, 30 miles sounded more interesting than 24 miles, so they used the bigger number?)

    • Re:Thank you! (Score:3, Informative)

      by Malor ( 3658 )
      The actual interesting part would be that if the composition were the same, a spherical object six times as wide would have 216 times as much mass.

      In other words, if it hit at anywhere close to the same speed, this one was A LOT more destructive.
    • Slide rules? You don't get out much, do you?
    • Now, if someone could do the volume problem so we could estimate relative mass, I wouldn't have to try to remember how to do cubes on my sliderule. (Damn, cube of 3, cube of 15...)

      My sliderule which is made of bamboo, I might add, not your shitty plastic substitute. No, alas, it's not a Versalog.

  • Notes (Score:3, Informative)

    by hunte ( 455338 ) on Saturday June 03, 2006 @06:23AM (#15460899) Homepage Journal
    6 miles = 9.66 kilometers

    http://en.wikipedia.org/wiki/Chicxulub_Crater [wikipedia.org]
  • In related news:

    A scientific organization named GHERIN has established a base in Antartica to study the phenomenom that they call "the first impact".

  • Is gravimetrics really this efficient? (Score:3, Interesting)

    by Reverse Gear ( 891207 ) on Saturday June 03, 2006 @07:50AM (#15461019) Homepage
    I am jut a bit lost here, how do they use gravimetric data to say with the certainty the article seems to suggest that this is an impact crater?

    As far as I know from my the few classes I have had on gravimetric data without the help of other data you are usually pretty lost. It would be very difficult to say how deep, what size and what weight anamoly the gravimetric anomily has and even more make out it's shape.
    Furthermore with these gravimetric data taken from a satelite and not from the surface you get even more "meaned data" (less precise) being further away from the anamoly I can figure, of course they probably have a huge data set and also extremely precise instrumentation at the satelite in space, maybe that makes up for the distance in some ways, but for now I remain very sceptical.

    Another thing that makes me wonder is why they don't talk about doing seismic or seismologic checks to confirm their theory. I actually thought that there was a few seismic stations places in this region, if this anamoly is as huge as the article suggests then I would think it should be pretty clearly visible in the seismic data.

    Anyhow gravimetrics is certainly not my area of expertise. I would if someone out there is able to show me where I go wrong if that is the case, then I'd be grateful.
    • They used the gravity fluctuations to identify the anomoly and then used airborne radar data to define the extent. I would hazard a guess that radar wasn't the only set of electronices that airborne survey was doing and that it would have included high res gravity and magnetics as well
  • When the scientists overlaid their gravity image with airborne radar images of the ground beneath the ice, they found the mascon perfectly centered inside a circular ridge some 300 miles wide -- a crater easily large enough to hold the state of Ohio.
    • a crater easily large enough to hold the state of Ohio.

      Freudian slip from an evil scientist with scary plans? Time to sell my Ohio real estate.
           
  • *remembers neon genesis*

    didnt a "explosion" happen due to the first angel?

    OH NO!! build EVAs!!

  • Flash of light (Score:3, Interesting)

    by RNLockwood ( 224353 ) on Saturday June 03, 2006 @10:55AM (#15461632) Homepage
    Slashdoters are technical sorts so I don't think it's too pendantic to note that a meteor is a flash of light caused by a meteorite.

    Comparing the widths of the meteorites is a lot less interesting than realizing that the mass ratio is about 125:1. Actually I suspect that the mass was estimated first from the size of the crater and then the diameter calculated, converted from metric to American, and the word "diameter" changed to the more easily understood "width".
    • Slashdoters are technical sorts so I don't think it's too pendantic to note that a meteor is a flash of light caused by a meteorite.

      If we're going to be pedantic, something is a meteorite only if it strikes the earth. A meteor is merely an object from space (man-made satellites usually excluded) that enters the Earth's atmosphere, and may or may not become a meteorite--most meteors are too small and completely burn up/disintegrate before hitting land.

  • Link to OSU research (Score:4, Informative)

    by KwKSilver ( 857599 ) on Saturday June 03, 2006 @10:59AM (#15461655)
    The article posted above seems to be based on this [osu.edu] from Ohio State University, which is better illustrated, etc.

    If you want to "experiment" with results of various impacts, Arizona State has an online calculator [arizona.edu].
  • I'm so glad they closed the post by doing the complex math for us.My brain was feeling foggy this morning. G'day...

  • What A Wonderful Time It Was To Be Alive ... (Score:3, Interesting)

    by Melllvar ( 911158 ) on Saturday June 03, 2006 @11:22AM (#15461738)

    A couple of years ago an entirely different impact crater was discovered in Australia [ucsb.edu], with preliminary dating indicating that it happened at about the same time as this one. It, too, is huge -- not as monstrous as this here Antarctica sockdollager, but apparently about as apocalyptic as the one that reputedly KO'd the dinosaurs. Considering the history of our Solar System, I don't think that a multiple-impact armaggedon is at all out of the question. Hell, maybe we'll find even more impact craters, and have to come to the conclusion that it was some kind of supersized rain of fire that reset the planetary ecology switch.

    And then, of course, we shouldn't forget about the largest volcanic eruption in the history of the planet [le.ac.uk] that sparked up at just about the same time, too. An area roughly the size of Scandinavia simply melted into a mass of sulfurous, poisonous, volcanic goo for a couple of million years before settling down. I'm not terribly firm on my Permian Era geography, but I'd be willing to bet that the Siberian Traps event was pretty close to the opposite side of the planet at the time of the impacts.

  • My theory is trilobites grew large brains and built Hummers, which caused greenhouse gasses that killed a bunch of stuff, including themselves.
  • These 500 click sized craters are not all that uncommon. There is for example the Bushveld Complex in South Africa (the source of much of it's mineral wealth), which could have been an impact crater. Since it is so old, it is not possible to tell whether it was an impact crater, or a gigantic volcano, or an alien experiment with anti-matter gone wrong - either way, it is friggen huge. Despite it's size, the continent of Africa just shrugged it off and is none the worse for it. Also, a glance at the enor
  • A great read for anyone curious about the P-T extinction is Douglas Erwin's book Extinction [dannyreviews.com] . He doesn't come to any definite conclusions, but thinks the balance of evidence is against an extraterrestrial impact as a cause.

    Danny.

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