"new" method to detect ancient craters

[bobvanx]

Impacts change the lithosphere. The bedrock is cracked, vaporized, excavated... I wondered if, similar to the way rivers and coastlines can be traced by human habitation, if impact craters could be too. So I grabbed the NOAA USA at night image, and lo and behold, truly giant circles are inscribed by the placement of city lights! I outlined two of them in this image.

 

[tom_hobbes]

You may be on to something there. <div class="Discussion_UserSignature"> <p><font size="2" color="#339966"> I wish I could remember<br /> But my selective memory<br /> Won't let me</font><font size="2" color="#99cc00"> </font><font size="3" color="#339966"><font size="2">- </font></font><font size="1" color="#339966">Mark Oliver Everett</font></p><p> </p> </div>

 

[earthseed]

Half of your upper "circle" is in northern Ontario, where almost nobody lives. This observation is as meaningful as looking up at the night sky and observing that the stars form triangles.

 

[bobvanx]

Yeah, I wonder about that, too.<br /><br />Fortunately, circles are far harder to "suppose" than triangles. And the fact you mention, that it is sparsely populated, actually works in favor of pointing to an unsuspected phenomenon.<br /><br />In a sparsely populated area, why would people build towns along an arc like that? Is the bedrock specially cracked, so wells are easier to find? Is there a slight change in topograhy that people use to avoid flooding? Are there good rocks for building foundations, all piled up and nearer the surface?

 

[silylene old]

I have a hypothesis for the observed fairy rings of light.<br /><br />In the center of the ring is a big honker multi-gigawatt nuclear plant. The radius of the ring is the limit that the power lines can transmit without catastrophic overvoltage failure. Hence, all the towns within this radius are powered by the big nuke plant. The radius will increase when we start using superconducting power lines.<br /><br />'Course I wouldn't be kiddin', would I ? <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[rogers_buck]

Your map may not help locate meteorites, but it is a good guide where to go to look for meteors. (-;

 

[rogers_buck]

Second thought, look for "no trees". There are no trees on the moon! Why? The craters built them all into crates.

 

[bobvanx]

LOL

 

[bobvanx]

<blockquote><font class="small">In reply to:</font><hr /><p> The radius of the ring is the limit that the power lines can transmit without catastrophic overvoltage failure.<p><hr /></p></p></blockquote>Since the three or four rings that I see (there's one that straddles the Appalachians, centered on NC, and one that crosses through Texas and Mexico) are all roughly the same diameter, this seems quite plausible.<br /><br />I'll look up a map of the power grid.

 

[bobvanx]

I found an image of the US electrical grid. It shows the primary transfer and balancing stations, so it would show if there were "rings" created by central power generation.<br /><br />And it doesn't.<br /><br />I also show the other thousand-mile diameter circles that I see. Hopefully all this overlay of info isn't too confusing.

 

[Maddad]

Bob<br />That's an interesting conjecture about the lithosphere craters. I seem to remember a crater 89 million years old in Michigan or someplace like that. If it's the one in your first picture, then it would be the upper circle. I don't remember the size of the crater, although I seem to remember that it landed in two pieces, and it was vaguely the same size as the Chicxulub crater of 65 million years ago. This is an idea that would be interesting to followup.

 

[bobvanx]

Random points get organized by human visual processing into whatever the human wants to see.<br /><br />However, the placement of cities and villages is not random. Your conclusion that we can find whatever we are looking for, however fabulous, is without merit.<br /><br />Try again<br /><br />LOL

 

[bobvanx]

The Yucatan impact is tiny compared to these circles. These are so big that they really can't be impact craters, given what we know about how much energy would be released to make a feature this large. Except, that there are craters this big on the Moon, and on Mars, and on Callisto... places where plate tectonics doesn't erode your giant craters.<br /><br />I did a couple of searches, and discovered that continents are built of "cratons." Different geologists use different methods to map the cratons of North America and get several different results. <br /><br />I found it's also hypothesized that there were 15 to 25 final, large impactors in the last 200 million years of our planet's accretion. These would have moved so much material around (this is after the stuff that the Moon is made from was blasted away) that the idea is these became the sites of the mantle plumes.<br /><br />Anyway, there are lots of geophysicists and geologists who are researching these things, and they all have a corner of the "truth" which they are trying to push. I didn't know it was such a dynamic time to be in that field!<br /><br />I'm just suggesting, that there is some sort of reason why people are building towns along these arcs. And I've been able to rule out gross topography as well as power transmission.<br /><br />Would it blow your minds if I let you know that there are arcs which are half on this side of the Atlantic, and half on the other side?

 

[silylene old]

I was kidding you know! <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[earthseed]

There is no way these circles, whatever they are, have anything to do with ancient meteorite impacts because plate tectonic movements have completely shuffled the organisation of the continents. What makes up North America today are pieces of many ancient continents that have collided together. These continent pieces are called terranes. As you can see from the attached map (from here), the circles cross over multiple terranes, so if they have a physical existance they are only hundreds of millions of years old, not billions.<br /><br />The reason geologists don't mention these ancient craters is because they do not exist. The oldest known craters (from here) are about 2 billion years old. Before that tectonic shuffling has obliterated them.<br /><br />

 

[Maddad]

Bob<br />Yeah, I think you're right that these structrures are too large to be impact craters. Also anything from when our planet was 200 million years old means that they're 4,300 million years old. Mountain ranges erode away to their roots in less than a tenth that time. These circles are way too circular for having hung around through all that tectonic time.<br /><br />As for arcs showing up on opposite sides of the Atlantic, that actually makes a lot of sense. The Appachalian (sp) mountains run north, supposedly ending in Nova Scotia, but they pick up again in Europe. The Atlantic ocean opened up between these sections and moved them apart. If whatever geologic source that created your arcs made them centered on the mid atlantic ridge, then they'd have spread apart by the width of the Atlantic in the last 180 million years.<br /><br />

 

[bobvanx]

<blockquote><font class="small">In reply to:</font><hr /><p>There is no way these circles, whatever they are, have anything to do with ancient meteorite impacts because plate tectonic movements have completely shuffled the organisation of the continents.<p><hr /></p></p></blockquote>I've learned to stay away from absolutes.<br /><br />Plate tectonics moves <i>plates</i> but the continent riding on top goes through a different sort of morphological shift, like a newsprint image on Silly Putty as you shift and stretch it. Here's a mechanism by which these <i>could</i> be records of impacts from the last phase of planet building. The crust would have been really pliable, and the planet scarcely differentiated. So a really large impactor alters the crust, the upper mantle, the lower mantle, the mantle/core interface... in other words, all the convective layers of rock. All of the later, surface events, the continent building events, occur on top of this. But it's such a profound alteration of the underlying processes, that some sort of measurable phenomenon exists to this day.<br /><br />As a hypothesis.<br /><br />PS thanks for the geology map. There are many of these, and some show the boundaries are coincident with the arcs.

 

[earthseed]

I usually (not absolutely) avoid absolutes myself, but in this case it seems quite certain. Plate tectonics does not just take continents for a ride, it splits them apart and re-combines them. And as maddad points out, continents also get deformed so ancient craters would no longer be circular.<br /><br />As for deformation below the crust, the mantle is fluid enough that no trace of any disturbance would last for long. This is especially true if plate motion is driven by whole mantle convection, which is still being debated. Back in the first few hundred million years of Earth's existance the mantle would have be much more fluid, as would the crust itself to some extent. There may someday be a way to detect remnants of ancient craters, but the craters as a whole are long gone.

 

[nexium]

Hi bobvanx: I'm impressed. I think the arcs are much too smooth, and the radius too constant for this to be coincidence. If not impact cretors, then they have another cause. Projectiles are thown from impacts one hundred? times the distance to the creater rim. Could air resistance make the range of these projectiles almost independent of the impactor's mass, velocity and impact angle? There does seem to be a small range of radius.<br /> How are similar circles found in Austrailia, Russia, Europe etc. different than the USA and Southern Canada? The cause could date back hundreds of years rather than 4.5 billion years. I suspect Earth has been hit hundreds of times by the equivelent of the 65 million year ago impact in the recent billion years. Perhaps this casts reasonable doubt on some or most of the plate tetonics theory. I tend to be suspicious when a majority of scientists accept a new theory in a decade or two. Perhaps deflecting impactors is more urgent than most of us think? Neil

 

[a lone wolf]

of interesting note, that upper circle does include the second largest known crater in the world, the so called Sudbury Crater, which is IN northern ontario...

 

[cookie_thief]

I know this sounds pretty obvious but have you compared your "arcs" with maps of gravimetric data or magnetic anomalies to see if there is any correlation?

 

[earthseed]

Yes, but observe that the Sudbury Crater is no longer round. Any round artifact is definitely <b>not</b> an ancient crater. This whole thing is nonsense. But I am wasting my time.

 

[vogon13]

Quite a few more 90 degree alignments apparent (to me at least) than circular ones. Would you speculate as to an extraterrestrial mechanism for generating <i>squares</i> and <i>rectangles</i>? <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>