Consequences of Chicxulub impact

  • #1

Main Question or Discussion Point

Is it possible that the chicxulub impact is responsible for the earths magnetic pole being tilted 15 degrees off the earths axis? If so, at what angle would the impactor have to have struck & based on that and the earths current angle can we estimate not only the approximate day of the year upon which it struck but by tracing its tragectory backwards, trace from where in or out of the solar system the impactor originated?
 

Answers and Replies

  • #2
tiny-tim
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Hi Godspanther! :smile:

According to http://en.wikipedia.org/wiki/Chicxulub_crater#Impact_specifics", the meteor was 6 miles in diameter, which is very small compared with the total mass of the Earth's crust.

And the magnetic field depends on the interior of the Earth, which is unlikely to be affected by such a small tap on the crust. :wink:
 
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  • #3
Rail gun physics

A small tap on the crust? Are you for real? The velicity of the impactor greatly increases the effect of the impact. Take the rail gun for example a very small projectile accelerated to hypersonic speeds. Its like a needle strucking with the force of an artillery shell. And we aren't talking about a needle we're talking about a chunk of rock 6 miles across moving at 25 miles a second or faster. The shockwaves from krakatoa circled the earth 7 times. The impact in the Yucatan was 500000 times as powerful. Its a miracle the planet wasn't knocked completely out of its orbit. In point of fact I thinks its a large reason why our orbit is eliptical. I think our orbit used to be more circular which would have given the whole planet a far more temperate climate.
 
  • #4
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In point of fact I thinks its a large reason why our orbit is eliptical. I think our orbit used to be more circular which would have given the whole planet a far more temperate climate.
I do agree with your main point, but i disagree on the matter of elliptical orbit significantly affecting climate.. Our seasonal temp variations are due to the earth's tilt. I.e., northern hemisphere 'summer' occurs when sun's rays strike that region of the earth's surface in a more-perpendicular fashion. Likewise, winter there occurs when our solar orbit is at a location where Sol's rays meet earth at a lower angle. The degree of 'ellipse' of earth's orbit is trivial.
 
  • #5


Its a miracle the planet wasn't knocked completely out of its orbit.
The earth is a ball of rock 8000 miles in diameter moving at 20miles/second around the sun.
To change this you need to hit it with something of similar size at similar speed - a meteor does zilch
 
  • #6
re: NobodySpecial
True, true, I got a little carried away with my response it's just that tiny tim was so oblivious to the obvious it irritated me. Which brings me to my next reply...

re: tkjtkj
You aren't putting 2 & 2 together. The tilt and the ellipse. They may both have had the same cause. Before the impact the earth may not have had the tilt and may also have had a more cicrular orbit. This may have lead to the degree of seasonal variations.
 
  • #7
Ich
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Godspanther, you were asking for the magnetic poles, and tiny-tim answered your question.
Now you're asking about Earth being thrown off its orbit, or its rotatonal axis being tilted.
If you'd run the numbers, you'd find that the impact had the potential to change Earth's rotation by 0.000004%, its orbital velocity by 0.00000002 %. So it really is a small tap on the crust, and tiny-tim is completely justified in being oblivious to the alleged "obvious".
 
  • #8
tiny-tim
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Thanks Ich! :smile:

Just to fill out the numbers, if the meteor had a diameter of 6 miles, and the Earth's diameter is 8000 miles, and assuming the same average density, the ratio of the masses is 8000/6 cubed, or just over 2,000,000,000.

For a meteor moving at 40 km/s, that imparts a maximum additional speed to the Earth of 40/2,000,000,000 km/s, or about 7 cm per hour, or about 1/700,000,000 of the Earth's orbital speed …

if it was in the right direction (unlikely!), this change in the Earth's orbital speed could change the length of the year by about 50% more than that, or about 0.05 seconds.

As for the seismic effects, Godspanther might like to test this himself by shooting a bullet at the Rock of Gibraltar! :biggrin:
 
  • #9
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From a recent 'Discovery' documentary on asteroid impacts (YMMV), the NASA hypervelocity impact modelling plus the debris field's depth across North America suggest that the bolide came in, IIRC, from South East at about 30 degrees above horizon.

Uh, my take on the polar-wobble effects is that there may have been a few more leap-seconds that year...

A major constraint on anything more dramatic is the tidal effects of the Moon on Earth's Equatorial bulge: Think of it as a mass-damper...

If you want to tip the polar axis much or significantly change the day length of a terrestrial planet, IMHO, you should impact a dwarf planet: Last time that happened, IIRC, was the BigSplat that produced the Moon we know. Anything less just craters-- Look at the Moon !!
 
  • #10
collinsmark
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(Going back to the original question for just a moment...)
Is it possible that the chicxulub impact is responsible for the earths magnetic pole being tilted 15 degrees off the earths axis?
And just so we're on the same page, Earth's magnetic field is not at a constant 15o from the rotational axis. The magnetic poles meander around quite a bit from year to year, and sometimes even undergo complete polarity reversals. So it doesn't seem like meteor impacts are the culprit here.

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magearth.html" [Broken]

http://en.wikipedia.org/wiki/Earth%27s_magnetic_field" [Broken]

[Edit: Although the reversals don't happen very often, perhaps every 300,000 years or so. But the specific positions of the magnetic poles change travel around quite a lot. They're significantly different now (multiple degrees), compared to what they were even a decade ago.]
 
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  • #11
How about a polar shift? Could such an impact cause one?
 
  • #12
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Uh, IIRC, the Boxing Day mega-quake prompted an extra leap-second, indicating that the Earth's rotation was minutely (pun) altered by the mass shift, but I don't think there was any detectable polar shift. That would have required an urgent update of navigational and astronomical Ephemerides, and certainly have drawn the tabloids' attention...
 
  • #13
tiny-tim
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Hi Nik_2213! :smile:
Uh, IIRC, the Boxing Day mega-quake prompted an extra leap-second, indicating that the Earth's rotation was minutely (pun) altered by the mass shift, but I don't think there was any detectable polar shift.
No, no earthquake has ever been remotely large enough to make a difference of one second.

The largest recent effect seems to have been 0.00000268 seconds, in 2004 … see http://en.wikipedia.org/wiki/Leap_second#Reason_for_leap_seconds".

See also "http://www.airspacemag.com/flight-today/One-More-Second.html"" (by 0.00000126 seconds) by Alan Buis of NASA (1 Mar 2010) …
JPL research scientist Richard Gross computed how Earth's rotation should have changed as a result of the Feb. 27 quake. Using a complex model, he and fellow scientists came up with a preliminary calculation that the quake should have shortened the length of an Earth day by about 1.26 microseconds (a microsecond is one millionth of a second).

Perhaps more impressive is how much the quake shifted Earth's axis. Gross calculates the quake should have moved Earth's figure axis (the axis about which Earth's mass is balanced) by 2.7 milliarcseconds (about 8 centimeters, or 3 inches). Earth’s figure axis is not the same as its north-south axis; they are offset by about 10 meters (about 33 feet).

By comparison, Gross said the same model estimated the 2004 magnitude 9.1 Sumatran earthquake should have shortened the length of day by 6.8 microseconds and shifted Earth's axis by 2.32 milliarcseconds (about 7 centimeters, or 2.76 inches).

Gross said that even though the Chilean earthquake is much smaller than the Sumatran quake, it is predicted to have changed the position of the figure axis by a bit more for two reasons. First, unlike the 2004 Sumatran earthquake, which was located near the equator, the 2010 Chilean earthquake was located in Earth's mid-latitudes, which makes it more effective in shifting Earth's figure axis. Second, the fault responsible for the 2010 Chiliean earthquake dips into Earth at a slightly steeper angle than does the fault responsible for the 2004 Sumatran earthquake. This makes the Chile fault more effective in moving Earth's mass vertically and hence more effective in shifting Earth's figure axis.​

The primary sources are calculations by Richard Gross, the geologist at JPL NASA … see references at the end of "http://nasadaacs.eos.nasa.gov/articles/2010/2010_gps.html" [Broken]" by Jane Beitler of NASA (16 Nov 2010).

btw, "figure axis" means the principal axis of a body with the largest moment of inertia
 
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  • #14
I'm not talking about an earthquake alone causing a polar shift although the asteroid impact certainly would have caused some. I'm talking about the results of the impact.
 
  • #15
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Wouldn't the precision of the earth be caused by natural causes due to gravity and the orbit of the earth?
 
  • #16
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I'm talking about the results of the impact.
If you'd run the numbers, you'd find that the impact had the potential to change Earth's rotation by 0.000004%, its orbital velocity by 0.00000002 %. So it really is a small tap on the crust, and tiny-tim is completely justified in being oblivious to the alleged "obvious".
There you go.
 
  • #17
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Wouldn't the precision of the earth be caused by natural causes due to gravity and the orbit of the earth?
I assume you mean "earth's precession" (also known as 'precession of the equinoxes').

Yes, precession is a consequence of gravity, and i refer you to:
http://en.wikipedia.org/wiki/Axial_precession_(astronomy)

(i just edited that article to correct a significant but unintended error. It is obvious that the orig author didn't mean to say what he stated: that the precession ('wobble') causes the earth axis to trace a cone, when in fact it traces two cones, joined at their apices ..the 'pointy part' ;)
 
  • #18
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There you go.
I wonder if Ich would share with us those calculations

(his comment doesn't include units: how is he defining 'rotation'? as in 'length of day'? as in 'velocity'? .. 'momentum'?? etc etc)
 
  • #19
tiny-tim
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hi tkjtkj! :smile:
(i just edited that article to correct a significant but unintended error. It is obvious that the orig author didn't mean to say what he stated: that the precession ('wobble') causes the earth axis to trace a cone, when in fact it traces two cones, joined at their apices ..the 'pointy part' ;)
but that is a cone!

(i accept that http://en.wikipedia.org/wiki/Cone_(geometry)" [Broken] supports you rather than me on this, but …)

a cone is the whole thing, on both sides of the vertex (apex) …
http://en.wikipedia.org/wiki/Conic_section#Introduction"
In the remaining case, the figure is a hyperbola. In this case, the plane will intersect both halves (nappes) of the cone,​

there's no harm in using the word to mean just a semi-cone where the context is clear …

but a conic section, for example, is a section of the whole thing

surely we say that a hyperbola is what we get "when a plane cuts a cone", not "when a plane cuts a pair of cones joined at their apices" ? :smile:
 
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  • #20
tiny-tim
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Apollonius of Perga (oh, that Apollonius! :wink:) defined conic sections in his work Conics …

from http://mathdl.maa.org/mathDL/46/?pa=content&sa=viewDocument&nodeId=196&pf=1" [Broken] …

Apollonius redefined the cone:

"If from a point a straight line is joined to the circumference of a circle which is not in the same plane with the point, and the line is produced in both directions, and if, with the point remaining fixed, the straight line being rotated about the circumference of the circle returns to the same place from which it began,

then the generated surface composed of the two surfaces lying vertically opposite one another, each of which increases indefinitely as the generating straight line is produced indefinitely, I call a conic surface, and I call the fixed point the vertex, and the straight line drawn from the vertex to the center of the circle the axis" [1, p. 604].​
 
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  • #21
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Apollonius of Perga (oh, that Apollonius! :wink:) defined conic sections in his work Conics …

from http://mathdl.maa.org/mathDL/46/?pa=content&sa=viewDocument&nodeId=196&pf=1" [Broken] …

Apollonius redefined the cone:

"If from a point a straight line is joined to the circumference of a circle which is not in the same plane with the point, and the line is produced in both directions, and if, with the point remaining fixed, the straight line being rotated about the circumference of the circle returns to the same place from which it began,

then the generated surface composed of the two surfaces lying vertically opposite one another, each of which increases indefinitely as the generating straight line is produced indefinitely, I call a conic surface, and I call the fixed point the vertex, and the straight line drawn from the vertex to the center of the circle the axis" [1, p. 604].​
Well, good for Appolonius .. I don't think that many of us would agree that our language must be as defined by great philosophers of ancient ages .. If so, perhaps we'd logically have to include their behaviours as well, including taking the hemlock for a perceived transgression.

My comments here are made to clarify a statement on Wiki that is confusing to the many who lack strong math backgrounds. For example, when i join the masses at the ice-cream store, are you suggesting that i order a 'Half a cone' of chocolate?? No, you cant mean that!. Also, the 'wobble' as described on Wiki would mislead the math-challenged to conclude, eg, that the south pole in this regard is stationery!! ..showing the 'wobble' to involve the north pole only!! That is consistent with the public's understanding of what a cone is.
and totally fails to reflect what a precession is. That is why i edited the article.

Additionally, would you seriously propose that the " X " character is a conic section?? You might, (and i'd agree) but you'd not be supported by any cross-section (pun intended!) of the public!

I thank you for your partial admission (to this point at least) that the Wiki article you 1st referenced confirms my position .. Together with the 2nd article that supports you, they en masse confirm that the issue truly can be confusing to the general public ( the 'public' that wiki is designed to serve) .. again, confirming my editing as appropriate as it serves to prevent a totally incorrect conclusion. What say ye? ;)
 
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  • #22
If high impact asteriods or comets aren't to blame, then do scientists know what exactly caused the earth's wobble? (not referring to the Chandler wobble, btw). And, isn't it theorised that approx every 26 million years the fossil record indicates a mass extinction, coinciding with our solar system crossing the densest part of the Milky Way galactic disk (aforementioned precession of the equinoxes), thus perturbing the Oort Cloud, giving us a high likelyhood of impact events?
 
  • #23
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If high impact asteriods or comets aren't to blame, then do scientists know what exactly caused the earth's wobble? (not referring to the Chandler wobble, btw). And, isn't it theorised that approx every 26 million years the fossil record indicates a mass extinction, coinciding with our solar system crossing the densest part of the Milky Way galactic disk (aforementioned precession of the equinoxes), thus perturbing the Oort Cloud, giving us a high likelyhood of impact events?
In a word, no, I'm pretty sure it doesn't because there isn't a densest part per se and it likely wouldn't have any significant effect on the Oort Cloud. I've never seen a paper on it or a link to such a paper, in fact the only links I have seen have been to the 2012 Hoax.

Edit: I have found the source of the claim but mass extinction events also don't occur every 26Myrs.
From Wiki said:
However, mass extinctions do not show any (statistically significant) periodicity.
http://en.wikipedia.org/wiki/Shiva_Hypothesis
 
  • #24
Edit: I have found the source of the claim but mass extinction events also don't occur every 26Myrs.

http://en.wikipedia.org/wiki/Shiva_Hypothesis[/QUOTE]

I thought the same thing until I realised how likely it is that an impact event approx 35 Myrs ago triggered the ice age. I agree that one should shy away from the 2012 rubbish.
 
  • #25
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It is my layman's understanding that the impactor that created the moon probably had far more effect on the Earth's tilt, rotational velocity, and orbital eccentricity than anything else that came after it. That impactor was theorized to be the size of Mars, which dwarves the impactor at Chicxulub*. ALL impacts impart some energy to the planet, so your hypothesis has merit, but many of the microscopic changes to our planet's magnetic, rotational, and orbital characteristics cancel out over time because impacts happen in varying directions, Earthquakes happen on all sides of the crust, and 2-yr olds jump up and down on their beds constantly (mine jumps very high).

The Earth's wobble would probably be extremely high regardless of its history, if other planets are any indication. The Moon, which I have hinted probably had the biggest effect on it (that we know of), has actually been responsible for slowing the Earth's rotational speed down along with stabilizing its tilt (among other things). So again, while the*Chicxulub impact probably resulted in a tiny change to the characteristics you mention, you don't need to factor it in compared to the largest impacts our planet has seen (during the initial formation of our planet in its accretion phase,*Chicxulub-sized impactors could have struck DAILY).

Regarding the Earth's magnetic field, this is generated from the magnetic dynamo at the Earth's core. Again, there is almost no chance it was affected by the*Chicxulub impact. However, just for argument, the impactor probably DID deposit SOME iron onto the surface, and possibly even beneath the outer crust when it blew a hole in it, so maybe a tiny fraction of that iron did find its way to the core through convection or other transfer mechanism. Of course, if such an impact happened while our planet was still molten, then it is quite possible that a majority of the iron could have reached the core and added to the magnetic dynamo. The amount is still statistically insignificant, but worth noting. And perhaps the shock waves from the impact caused the inner mantle to oscillate over the core in a way which disrupted the magnetic field for a short time. But once again, I see little lasting impact.

Lastly, I have seen the theory regarding the Earth's orbital oscillation through the galactic plane, and the concept that our planet is more susceptible to cosmic rays when out of the protection of the galactic disc as well as more likely to pass through interstellar debris during these travels, and the possible link to extinction events. The theory is intriguing. I most recently read it while reading "Death From The Skies", by Phil Plait. Fun reading, but it is not a grand thesis on the matter either. I'll consider any theory, though. :)

Hopefully I didn't mis-state too many things here, and helped out a little. I'm not an astronomer or physicist, but I try hard!
 

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