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Could the Chicxulub asteroid have changed Earth's orbit or axis at all

  1. May 4, 2010 #1
    I heard that the recent Chile earthquake moved Earth's axis by 8cm or so. Could the Chicxulub asteroid (or the even bigger, Antarctic one I just http://www.dailygalaxy.com/my_weblog/2010/03/did-the-planets-most-massive-asteroid-impact-ever-occur-in-antarctica-nasa-gravity-maps-point-to-yes.html" [Broken] about) have changed our orbit or our axis in a way that would have affected climate or life or anything that we can investigate?
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. May 6, 2010 #2

    Xnn

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    No; the size of these asteroids in comparison to the earth are very small. While the could alter the earths orbit on the order of a cm or so, that would not be enough to alter earths climate in a meaningful way.

    The immediate impact of such collisions on the other hand, have an immmense short term effect on the earth. The surface is incinerated followed by a cooling period from all of the dust obscuring the sun. Once the air clears, the climate returns to near it's previous norm.

    The biggest control knob for the earth's climate is well known and understood.

    http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter1.pdf

    This video is interesting. Richard Alley is a well respected lead author for the IPCC.
    Here, he gives an interesting talk on the history of the earth and what has changed over time.

    http://www.agu.org/meetings/fm09/lectures/lecture_videos/A23A.shtml
     
  4. May 6, 2010 #3

    D H

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    The question raised in the title of the thread, "Could the Chicxulub asteroid have changed Earth's orbit or axis at all" and the question raised in the original post, "Could the Chicxulub asteroid have changed our orbit or our axis in a way that would have affected climate or life" have very different answers. It certainly did change the Earth's orbit and rotation somewhat, and equally certainly that "somewhat" is a rather insignificant amount. I calculate that the change in length of day would be less than a millisecond and that the change in the Earth's rotation axis of less than 10 milliarcseconds. That is not going to change the climate in and of itself.

    The impact almost certainly did change life. It is the leading suspect in the extinction of dinosaurs, for example.
     
  5. May 6, 2010 #4
  6. May 13, 2010 #5
    I find this question very interesting

    The following are excerpts from
    Flannery, Tim; The Eternal Frontier, an ecological history of North America and its peoples; Atlantic Monthly Press, New York, NY; 2001

    p13
    p13 & 14
    p14
    p14
    p14
    p16
    p16
    p16
    p17
    Therefore, based on the above bold information it appears plausible to me that the Earth's tilt axis was impacted but not sure the extent.

    One thing that was quoted in the above book about tree growth rings prior to Chicxulub states on pages 12 & 13
    I am not sure if this indicating that there was a zero tilt angle prior to Chicxulub.
     
  7. May 14, 2010 #6
    Maybe check your basic mechanics. Any force impulse on a rotating body causes nutation, basically it does not change the direction of the spin axis.

    About the relative sizes, if we'd decrease the probably some 10 km diameter of the meteorite to a sand grain of one millimeter, the earth would have had a diameter of 1.27 meters of solid rock with a density more like lead or even mercury in the core. Now what is that sand grain doing?

    Another thing, if something had enough impulse to start changing anything to the earth's rotation, mind that such an impulse takes about 90 minutes to reach the other side of the earth. So if the first side starts doing things like that, the other side would not know about until 90 minutes later, hard to imagine what that would do to the earth.

    On the other hand, such an impact would change the balance of mass on Earth, which could change the direction of the inertia tensor. That would mean that the earth would rotate slightly to realign the inertia tensor with the spin axis. But this would not change the direction of the spin axis, only earth's oriention in relation to the spin axis. This is known as polar wander. But don't expect a lot of this, since the equatorial bulge is playing a major role to the direction of the intertia tensor.

    Not that a lot can happen with such an impact. Interesting is the hypothesis about antipode volcanism in relation to such a major impact and in this case the Indian deccan traps could be a candidate.
     
    Last edited: May 14, 2010
  8. May 14, 2010 #7

    D H

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    That is the wrong physical model, Andre. That paper refers to the problem of the motion of a symmetric top with one point fixed. The right physical model for an impact is conservation of angular momentum. An impulsive torque applied to an otherwise isolated rotating body with a spherical mass distribution will change the body's rotation rate, its rotation axis, or both. The body will not precess or nutate as a result of this impulsive torque because isolated bodies with a spherical mass distribution cannot precess or nutate.

    Ignoring effects due to changes in the Earth's inertia tensor, the sole effect of a north-south meteor impact will be to change the axis about which the Earth is rotating. The change would have been a very, very small amount in the case of the Chicxulub asteroid. In post #3 I indicated that this would be on the order of 10 milliarcseconds for a pure north-south collision. A shift of 10 milliarcseconds is not going to affect the climate.
     
  9. May 14, 2010 #8
    You are right, thanks

    Could, however, the equatorial bulge have some function as sort of 'fixed point' in the gravitational interaction with sun and moon, changing the precession rate?
     
  10. May 14, 2010 #9
    Careful! The link you referred to has no mention of "antipode volcanism". Rather, this work talks about volcanism at the site of impact due primarily to decompression melting. There is absolutely no mechanism there to suggest the Chicxulub impact had anything whatsoever to do with Deccan Traps volcanism.

    Looking at this further, if this work is correct why did we not get volanism at Chicxulub? Probably because impact related volcanism is most likely to occur on oceanic crust, and Chicxulub is on the continental crust.
     
  11. May 14, 2010 #10
    Okay I try to be careful. I'm not stating anything. Merely mentioning that there is a hypothesis about bolide impact and antipode trap volcanism. In this published paper a link is made between the K-T extinction and the Deccan traps (caption fig 1). I'm not aware that there is any concrete proof or refutation yet.
     
  12. May 14, 2010 #11

    LURCH

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    Yet most astronomers attribute the axial tilt of Uranus (almost 90o). So, impacts can cause axial tilt, according to those who know a lot more about it than I, but the K/T Killer wasn't impact enough, as has been pointed out.
     
  13. May 14, 2010 #12
    You can also consider the axial tilt of Venus to be almost 180 degrees, considering the retrogade spinning but that has been attributed to resonance between precession and obliquity cycles in the chaotic zone
     
    Last edited: May 14, 2010
  14. May 15, 2010 #13
    What is that link?

    The paper you linked to argues that the largest mass extinction might require that a large meteorite impact occur during the same period of time as massive continental volcanism. That's a far cry from what you appear to be proposing: that meteorite impacts trigger antipode volcanism.

    Just to be clear, that paper makes only a statistical link (given the frequency of those events) that they will probably have occured at the same time. There is no causal mechanism proposed.
     
  15. May 15, 2010 #14
    That's not the point, the point is that the hypothesis exists and that I did NOT propose it.

    Here is another one.

    And I'm not married to that hypothesis, the scientific method requires attemps to falsify it, to see if it can withstand any scrutiny. If it can, then it might be feasible. You can demonstrate maybe that N times pairs of apparantly simulataneous bolide impacts and trap volcanism at the other side of the globe can be statistically coincidal but that does neither proof nor falsify anything.
     
    Last edited: May 15, 2010
  16. May 15, 2010 #15
    Andre, thank you for finally backing up your claims with the Hagstrum paper you linked to, we got there in the end.

    And I realise you are not married to the hypothesis, when I said that is what you claimed I did not intend it to mean it was YOUR hypothesis and that you were married to it. I just noticed that the links you provided to back up your statement were not actually doing the backing up, so I flagged it, and now I have seen this paper that I might not have otherwise seen and it is very interesting to me. Incidentally, this field (particularly with regards to mantle convection and hotspots) is not too far from what I will be doing my PhD in, which is why I have an interest in this.

    The news is less good with regard to the link between Chicxulub and the Deccan Traps however, according to the Hagstrum paper:

     
  17. May 15, 2010 #16
    No, I am NOT claiming anything, again I merely point out that the hypothesis exists. And the reason that I'm splitting hairs is the regime here.
     
  18. May 17, 2010 #17
    Chill man. I didn't mean to misrepresent you.
     
  19. May 30, 2010 #18
    I recently found this article and since it wasn't previously cited in this thread, I added it for completeness.

    http://www.physorg.com/news132853165.html" [Broken]

    It is about Pyrite deposits across the Pennsylvania that may be tied to an Eocene (approximately 35.5 mya) meteor (Chesapeake Bay Impact Crater).

    I envision, with the Appalachians as a firm anvil that the impact energy of the meteor forced magma through fractures in the crust.

    Also, I read recently http://www.impacttectonics.org/impact-strains.html" [Broken]

    My main interest in this subject is how these impacts affect the world we live in today. It is believed that the Chesapeake Bay would not be located where it is, if it wasn't for the Chesapeake Bay Impact Crater and maybe there wouldn't be a Gulf of Mexico without Chicxulub because before, it was a shallow sea that most likely would have been filled in like the Great Plains.
     
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  20. May 31, 2010 #19

    Xnn

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    That statement attributed to Scheetz: "My guess is it probably changed the axis of the earth" is probably a misquote or misunderstanding.

    From the USGS here are the consequences of the Chesapeake Bay impact event:

    • The bolide carved a roughly circular crater twice the size of the state of Rhode Island (~6400 km2), and nearly as deep as the Grand Canyon (1.3 km deep).
    • The excavation truncated all existing ground water aquifers in the impact area by gouging ~4300 km3 of rock from the upper lithosphere, including Proterozoic and Paleozoic crystalline basement rocks and Middle Jurassic to upper Eocene sedimentary rocks.
    • A structural and topographic low formed over the crater.
    • The impact crater may have predetermined the present-day location of Chesapeake Bay.
    • A porous breccia lens, 600-1200 m thick, replaced local aquifers, resulting in ground water ~1.5 times saltier than normal sea water.
    • Long-term differential compaction and subsidence of the breccia lens spawned extensive fault systems in the area, which are potential hazards for local population centers in the Chesapeake Bay area.
     
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