Impact ~ NEO; Near Earth Objects

[The Doctor]

The web is filled with a lot of nonsense dressed up to look like science. This blog is a good example: A Catastrophe of Comets

The owner that blog "Crater Hunter" circles up things that he thinks are impact craters on Google Earth images. Someone cited this blog in the comment section of one of my Watts Up With That posts. To which I replied:

David Middleton says:
November 3, 2011 at 9:56 am

beng says:
November 3, 2011 at 8:52 am
[...]
And there’s quite a bit of geologic evidence for an impact, too:
http://craterhunter.wordpress.com/no...ment/part-two/

That blog is 100% science fiction.
There is nothing mysterious about the “Chihuahuan Ignimbrites”… And the rhyolitic eruptions from which they were sourced occurred in the Mid-Tertiary…

Petrogenesis of voluminous mid-Tertiary ignimbrites of the Sierra Madre Occidental, Chihuahua, Mexico
Maryellen Cameron, William C. Bagby and Kenneth L. Cameron
Abstract
The mid-Tertiary ignimbrites of the Sierra Madre Occidental of western Mexico constitute the largest continuous rhyolitic province in the world. The rhyolites appear to represent part of a continental magmatic arc that was emplaced when an eastward-dipping subduction zone was located beneath western Mexico.
In the Batopilas region of the northern Sierra Madre Occidental the mid-Tertiary Upper Volcanic sequence is composed predominantly of rhyolitic ignimbrites, but volumetrically minor lava flows as mafic as basaltic andesite are also present.
[…]
LINK

Major ignimbrites and volcanic centers of the Copper Canyon area: A view into the core of Mexico’s Sierra Madre Occidental
Eric R. Swanson, Kirt A. Kempter, Fred W. McDowell and William C. McIntosh
Abstract
Reconnaissance mapping along Copper Canyon highway has established ignimbrite stratigraphic relationships over a relatively large area in the central part of the Sierra Madre Occidental volcanic field in western Chihuahua, Mexico. The oldest ignimbrites are found in the central part of the area, and they include units previously mapped from north of the study area, in and around the Tomóchic volcanic complex. Copper Canyon, at the southern end of the study area, exposes younger units, including the intracaldera tuff of the Copper Canyon caldera and five overlying ignimbrites. Well-exposed calderas are found near San Juanito, in the central part of the map area, and at Sierra Manzanita, to the far north. Stratigraphic evidence for yet another caldera in the northern part of the area is found in the Sierra El Comanche. The stratigraphic and limited available isotopic age data suggest that volcanism was particularly active ∼30 m.y. ago. This reconnaissance survey also documented lava-flow lithologies consistent with previous observations from Tomóchic that intermediate lavas have erupted throughout that area’s volcanic history and that basaltic andesite became particularly abundant as felsic volcanism waned.
[…]
LINK

Even if the mid-Tertiary ignimbrites of the Sierra Madre Occidental of western Mexico were caused by an extraterrestrial impact event, it would have happened ~30 million years prior to the extinction of the North American megafauna.

That region of Mexico was over a subduction zone during the Tertiary. The region is rife with intrusive and extrusive Tertiary-aged igneous rocks and Cretaceous sedimentary rocks.

Crater Hunter seemed to be focused in a lineation that he claimed was part of "the pristine radial outwards flowing pyroclastic density current surrounding the mountain a couple of hundred miles away." As nearly as I could tell, he thought the NE-striking lineation in the image below was part of a recent radial pyroclastic flow...



A quick look at a geologic map of the region shows that the lineation is a ridge composed of NW-dipping Cretaceous-aged limestone & shale...



There are lots of volcanic and igneous outcrops in the area… All of them of Tertiary age and most rhyolitic… None of them are even remotely associated with impact-related geology.

[Mountain Man]

Where does the myth of the near-vertical impact come from in the first place? Hollywood?

[G David Bock]

Those links aren't to “articles.”. The first two are nonsensical blog posts and the third is a review of a book.

There is absolutely no geological evidence for Hapgood's theory and no evidence of physical polar reversals at least over the most recent 540 million years. And there's insufficient evidence over most of the previous 4 billion years to draw detailed conclusions.

Neither Hapgood nor Velikovsky, were proposing "pole reversal", a flip of 180 degrees. My understanding was that it was a sift more on the order of about 20 to 30 degrees, as show in the illustration of the first article I linked to.

[G David Bock]

The magnetic poles are continuously moving and frequently (geologically speaking) reverse polarity.

There is absolutely no geological or geophysical evidence of a physical polar reversal or the sort of crustal displacement depicted in 2012... At least not during the Phanerozoic (last 540 MY). That sort of stuff is 100% science fiction. Prior to the Phanerozoic, the geologic record is very sparse; but exhibits no clear evidence of that sort of thing either.. There's also no evidence of impacts large enough to alter the Earth's axis, rotation or orbit since the crust solidified.

I haven't seen "2012" yet, guess I may have to check it out from my local library. As for " impacts large enough to alter the Earth's axis, rotation or orbit since the crust solidified. ", I'll agree there likely is a low probability of that, if we are talking about affecting the full mass of the planet. My understanding is that what was proposed was a shifting of the crustal layer only producing the relative effect of a new location for axis on the surface. I'm not convinced we've seen enough of the ocean bottoms to rule out craters or evidence there.

[G David Bock]

According to Hapgood, crustal shift was made possible by a layer of liquid rock situated about 100 miles beneath the surface of the planet.

No such "layer of liquid rock" exists. Shear waves (S-waves) can't travel through fluid. A "layer of liquid rock situated about 100 miles beneath the surface of the planet" would be obvious. The only seismic evidence for a "layer of liquid rock" is the outer core at a depth of ~2,900 km (1,800 miles).



The crust overlies the mantle, which is solid. The crustal plates (the lithosphere) "drift" slowly over the asthenosphere.

While it is possible, maybe even likely, that there have been regional accelerations of tectonic activity, those accelerations would still be extremely slow by human standards.

In his best-selling book Earth in Upheaval, historian Immanuel Velikovsky gave an account of what might be expected when the Earth tilts on it's axis:

'Let us assume, as a working hypothesis, that under the impact of a force or the influence of an agent - and the Earth does not travel in an empty universe - the axis of the earth shifted or tilted. At that moment an earthquake would make the globe shudder. Air and water would continue to move through inertia; hurricanes would sweep the Earth, and the seas would rush over continents, carrying gravel and sand and marine animals, and casting them onto land. Heat would be developed, rocks would melt, volcanoes would erupt, lava would flow from fissures in the ruptured ground and cover vast areas. Mountains would spring up from the plains and would climb and travel upon the shoulders of other mountains, causing faults and rifts. Lakes would be tilted and emptied, rivers would change their beds; large land areas and all their inhabitants would slip under the sea. Forests would burn, and the hurricanes and wild seas would wrest them from the ground on which they grew and pile them, branch and root, in heaps. Seas would turn into deserts, their waters rolling away.

'And if the change in the velocity of the diurnal rotation [slowing the planet down] should accompany the shifting of the axis, the water confined to the equatorial oceans by centrifugal force would retreat to the poles, and high tides and hurricanes would rush from pole to pole, carrying reindeers and seals to the tropics and desert lions to the Arctic...

This is even more nonsensical than Edgar Cayce-style crap. There is no evidence of this sort of phenomenon in the geologic record - NONE.

The blog post sites the following "references":

[1] Adrian G. Gilbert & Maurice Cotterell. The Mayan Prophecies. Element Books, 1995. ISBN 1-85230-888-5
[2] Rand & Rose Flem-Ath (Discovering Atlantis)
[3] Rand and Rose Flem Ath, When the Sky Fell. In Search of Atlantis. Orion Books, 1996. ISBN 0 75280 171 6
[4] Immanuel Velikovsky. Earth in Upheaval. 1955. ISBN 0-671-45282-7

The references don't even constitute good science fiction.




The "con" blog post doesn't dodge any "harder to explain evidence" because no such exists. It actually gives too much credence to ECD by calling it a theory. Hapgood didn't construct a theory. He just made stuff up about things that he didn't understand.



Velikovsky presents nothing but nonsensical psychobabble.

So are you saying that the lava that comes flowing out of volcanos has risen from a depth of 1,800 miles or more?

I was under the impression it was a bit more closer to the surface.

IIRC, both Hapgood and Veklikovsy are suggesting that in rare circumstances, the lithosphere slides over the asethenosphere. Those circumstances were supposedly imbalance due to large build-up of ice at the poles and/or orbital and axial eccentricities. Seems to me that might not be enough which is why I suggested that perhaps a large enough impact event would do it. Otherwise, "gradualism" is the SOP of plate tectonics/continental drift.

The Carolina Bays, over 500,000 craters on land, are suggestive of such an event, especially if there was a larger mass impacted off shore in the Atlantic. The general line of the impact pattern is consistant with movement of the north rotational pole from Hudson bay area to it's current location. The elongation of the craters suggests an inclination of the impacts that could have produced a lateral thrust to North American plate.

[G David Bock]

One possible piece of physical evidence, from others as well as Velikovsky;

" ...One example he pointed to was Tiahuanacu in the Andes of South America. This city is situated on the Altiplano, an elevated plain some 12,500 feet above sea level. Agricultural terraces rise to 18,400 feet above sea level, to the present line of eternal snow on Mount Illimani. Since the conventional geologist's view is that mountain building takes hundreds of thousands of years, if not millions of years, this city high in the Andes has caused considerable controversy.

If the mountains were their present height when the city was built, it seems unlikely the terrain would support the large body of workers needed to haul the 60 ton blocks of granite into place. On the other hand, if the mountain was lower, that would be no problem. But because conventional geology has mountain building occurring slowly over many eons, this would mean the city was perhaps millions of years old. Clearly, this theory is bizarre, although it was advanced by H.S. Bellamy in his book Built Before the Flood; The Problem of the Tiahuanacu Ruins. The alternative, that the city rose to its present height after being built, perhaps some 10 to 12 thousand years ago, seems much more plausible."

http://members.tripod.com/~Glove_r/Velikovsky.html


Way I see it, we have three possible solutions;


1) The city is several hundreds of thousands to millions of years old. Since humans are only at most 200-280,000 years old, humans didn't build it. Also, IIRC, radio carbon testing of some food crop remains/roots found in those 18,400 foot elevation terrances show they were last farmed about 12,000 years ago.


2) Earth had some really intense "Global Warming" up till about 12,000 years ago (while also in and coming out of an Ice Age) that allowed higher temperatures at higher elevations, making these farming terraces workable. Don't recall there being similar evidence of agriculture at this elevation at other sites around the world for that time period.


3) There was some intense 'geological' activity that thrust this part of the Andes as much as an additional 5,000 feet higher in elevation. Near by hills show that Lake Titicacca has been tilted form an earlier shoreline displayed, which also looks like a rapid shift (no intermediary shorelines). Ruins that look like wharfs and docks are now hundreds of yards from current shoreline.


(Guess there could be a fourth, "better Sci-Fi", explaination?)

[G David Bock]

Another bit of evidence, summarized in that review;
http://members.tripod.com/~Glove_r/Velikovsky.html

Velikovsky proposed that the ice age could not have been a gradual process, neither in its original occurrence nor in its end, but rather, was sudden. He cited mastodons found in Siberia, still frozen and unthawed since they died, which sled dogs fed on without harm. When examined, leaves were found in the stomachs of the mastodons that now grow only 500 miles to the south of where the mastodons were found. Velikovsky felt that these huge creatures must have been "quick frozen" in a catastrophic event that suddenly shifted the global climate.


Velikovsky pointed out that in many places around the world, vast profusions of bones, jumbled together in mass graves, are found, some with more than 100 bones per square foot. "The state of the bones indicates a long and violent transportation before finally coming to rest." [2] The Agate Spring Quarry in Nebraska was partially excavated, a space of about 3450 square feet, which yielded over 164,000 bones, or about 800 animals. The most numerous were a small rhinoceros, a small, clawed horse and a giant swine. In Germany, in a gravel pit at Neuköln, fossilized remains of mammoth, musk oxen, reindeer, bison, lion, hyena, and two species of elephant were uncovered, again, with the bones all jumbled together, like the site in Agate Spring Quarry around the world. These fossilized remains have been dated to approximately 10 to 12 thousand years ago, or the end of the last ice age.

This begs a question ... why did so many splendidly adapted animals perish at the end of the last ice age, instead of at the beginning?"

In that book, "Earth in Upheaval" he has several chapters citing scores of such finds. Not by him, but by other explorers and researchers, whose works are cited. So much shattered remains of flora and fauna, from tropic, temperate, and tundra regions all heaped in a mass together at these locations suggests something like a tidal wave/tsunami that swept across continents to deposit these remains.

So what event (or cluster of events) could do this?

I doubt it was a few small bands of fur-clad "cavemen" with sharpened sticks, chipped flint and scraggy pack of dogs.

BTW, I'll agree that Velikovsky's idea that Venus was ejected from Jupiter and assorted close encounters with Earth before settling into it's current orbit does seem to be a highly improbable scenario. He was on to something about common cause/events behind the seemingly related "myths and legends" of cultures from around the world, but drew the wrong conclusions as to primary suspect for cause.

[The Doctor]

Neither Hapgood nor Velikovsky, were proposing "pole reversal", a flip of 180 degrees. My understanding was that it was a sift more on the order of about 20 to 30 degrees, as show in the illustration of the first article I linked to.

They assert that 20 to 30 degree occurred suddenly ~12kya; which is absurd.

[The Doctor]

So are you saying that the lava that comes flowing out of volcanos has risen from a depth of 1,800 miles or more?

I was under the impression it was a bit more closer to the surface.

Lava doesn't come from a global “layer” of liquid rock.

IIRC, both Hapgood and Veklikovsy are suggesting that in rare circumstances, the lithosphere slides over the asethenosphere. Those circumstances were supposedly imbalance due to large build-up of ice at the poles and/or orbital and axial eccentricities. Seems to me that might not be enough which is why I suggested that perhaps a large enough impact event would do it. Otherwise, "gradualism" is the SOP of plate tectonics/continental drift.

The Carolina Bays, over 500,000 craters on land, are suggestive of such an event, especially if there was a larger mass impacted off shore in the Atlantic. The general line of the impact pattern is consistant with movement of the north rotational pole from Hudson bay area to it's current location. The elongation of the craters suggests an inclination of the impacts that could have produced a lateral thrust to North American plate.

That's more sci-fi nonsense.

The Carolina Bays are sedimentary/erosional features with zero evidence of impact-related geology and the geographic North Pole hasn't moved more than a few centimeters over the last 12,000 years.

[The Doctor]

One possible piece of physical evidence, from others as well as Velikovsky;

" ...One example he pointed to was Tiahuanacu in the Andes of South America. This city is situated on the Altiplano, an elevated plain some 12,500 feet above sea level. Agricultural terraces rise to 18,400 feet above sea level, to the present line of eternal snow on Mount Illimani. Since the conventional geologist's view is that mountain building takes hundreds of thousands of years, if not millions of years, this city high in the Andes has caused considerable controversy.

If the mountains were their present height when the city was built, it seems unlikely the terrain would support the large body of workers needed to haul the 60 ton blocks of granite into place. On the other hand, if the mountain was lower, that would be no problem. But because conventional geology has mountain building occurring slowly over many eons, this would mean the city was perhaps millions of years old. Clearly, this theory is bizarre, although it was advanced by H.S. Bellamy in his book Built Before the Flood; The Problem of the Tiahuanacu Ruins. The alternative, that the city rose to its present height after being built, perhaps some 10 to 12 thousand years ago, seems much more plausible."

http://members.tripod.com/~Glove_r/Velikovsky.html


Way I see it, we have three possible solutions;


1) The city is several hundreds of thousands to millions of years old. Since humans are only at most 200-280,000 years old, humans didn't build it. Also, IIRC, radio carbon testing of some food crop remains/roots found in those 18,400 foot elevation terrances show they were last farmed about 12,000 years ago.


2) Earth had some really intense "Global Warming" up till about 12,000 years ago (while also in and coming out of an Ice Age) that allowed higher temperatures at higher elevations, making these farming terraces workable. Don't recall there being similar evidence of agriculture at this elevation at other sites around the world for that time period.


3) There was some intense 'geological' activity that thrust this part of the Andes as much as an additional 5,000 feet higher in elevation. Near by hills show that Lake Titicacca has been tilted form an earlier shoreline displayed, which also looks like a rapid shift (no intermediary shorelines). Ruins that look like wharfs and docks are now hundreds of yards from current shoreline.


(Guess there could be a fourth, "better Sci-Fi", explaination?)

This is like claiming that Paleozoic and Mesozoic marine fossils in modern mountain ranges is proof of Noah's flood.

Another bit of evidence, summarized in that review;
http://members.tripod.com/~Glove_r/Velikovsky.html

Velikovsky proposed that the ice age could not have been a gradual process, neither in its original occurrence nor in its end, but rather, was sudden. He cited mastodons found in Siberia, still frozen and unthawed since they died, which sled dogs fed on without harm. When examined, leaves were found in the stomachs of the mastodons that now grow only 500 miles to the south of where the mastodons were found. Velikovsky felt that these huge creatures must have been "quick frozen" in a catastrophic event that suddenly shifted the global climate.


Velikovsky pointed out that in many places around the world, vast profusions of bones, jumbled together in mass graves, are found, some with more than 100 bones per square foot. "The state of the bones indicates a long and violent transportation before finally coming to rest." [2] The Agate Spring Quarry in Nebraska was partially excavated, a space of about 3450 square feet, which yielded over 164,000 bones, or about 800 animals. The most numerous were a small rhinoceros, a small, clawed horse and a giant swine. In Germany, in a gravel pit at Neuköln, fossilized remains of mammoth, musk oxen, reindeer, bison, lion, hyena, and two species of elephant were uncovered, again, with the bones all jumbled together, like the site in Agate Spring Quarry around the world. These fossilized remains have been dated to approximately 10 to 12 thousand years ago, or the end of the last ice age.

This begs a question ... why did so many splendidly adapted animals perish at the end of the last ice age, instead of at the beginning?"

In that book, "Earth in Upheaval" he has several chapters citing scores of such finds. Not by him, but by other explorers and researchers, whose works are cited. So much shattered remains of flora and fauna, from tropic, temperate, and tundra regions all heaped in a mass together at these locations suggests something like a tidal wave/tsunami that swept across continents to deposit these remains.

So what event (or cluster of events) could do this?

I doubt it was a few small bands of fur-clad "cavemen" with sharpened sticks, chipped flint and scraggy pack of dogs.

BTW, I'll agree that Velikovsky's idea that Venus was ejected from Jupiter and assorted close encounters with Earth before settling into it's current orbit does seem to be a highly improbable scenario. He was on to something about common cause/events behind the seemingly related "myths and legends" of cultures from around the world, but drew the wrong conclusions as to primary suspect for cause.

100% absurd nonsense.

[Pirate-Drakk]

This is like claiming that Paleozoic and Mesozoic marine fossils in modern mountain ranges is proof of Noah's flood.



100% absurd nonsense.

I think maybe 99% nonsense. Something happened that they are trying to explain. While the explanation may be in question, the events to explain are not, and there is no alternative explanation that is more credible.

[The Doctor]

I think maybe 99% nonsense. Something happened that they are trying to explain. While the explanation may be in question, the events to explain are not, and there is no alternative explanation that is more credible.

To which 1% of the nonsense is there no credible alternative?

[G David Bock]

A RE-EVALUATION OF THE EXTRATERRESTRIAL ORIGIN OF THE CAROLINA BAYS

ABSTRACT


Controversy as to the origin of the Carolina Bays has centered on terrestrial versus extraterrestrial theories. Meteoritic impact has been considered the primary causal mechanism in extraterrestrial models, but alternatives such as comets and asteroids have not been adequately considered. Comets may explode during fall and produce depressions which would conform to the morphology of the Bays. Only a comet appears to satisfy the constraints imposed both by extraterrestrial requirements and observed terrestrial characteristics.


CONCLUSION


The proposed model with shock waves from cometary fragments exploding above the surface creating a series of similar landforms is conceptually very simple, and is far less complex than most of the terrestrial models postulated recently. For geometrically regular forms such as Carolina Bays we prefer a simple causal mechanism if it is feasible.


Examination of impact mechanics and Carolina Bay morphometry eliminates traditional impact phenomena resulting from meteoroid swarms or asteroids. However, the unique orbital and physical characteristics of a comet favor a model in which a high velocity retrograde comet or a low velocity prograde comet collided with the Earth. The incoming nucleus approached from the northwest and fragmented. The fragments, diverging from the main trajectory, volatized and subsequently exploded in the atmosphere near the surface. The resultant shock waves created shallow elliptical depressions which are best displayed in the sandy sediments of the Coastal Plain. ...


http://abob.libs.uga.edu/bobk/cbayint.html


This is an event very similar to the Tunguska Blast which I provided some information and links on in the opening posts of this thread. The pattern of craters suggests there may have been more that fell off-shore, in the Atlantic Ocean. How much and what mass I'll admit remains to be determined.


The circumstances of Tiahuanacu I cited above are established geography/geology facts, denying them won't make them go away.


Similar applies to the "bone yards" of mangled flora and fauna about the world, the frozen mammoths, and similar debris cited in "Earth in Upheaval". These hundreds of sites and examples are matter of record that are better served by explanation than denial.

[G David Bock]

This is like claiming that Paleozoic and Mesozoic marine fossils in modern mountain ranges is proof of Noah's flood.



100% absurd nonsense.

Rather than a world covered suddenly by water from a rainfall, ECD with continental sweeping tsunamis has been proposed as an alternative explanation.

[The Doctor]

Rather than a world covered suddenly by water from a rainfall, ECD with continental sweeping tsunamis has been proposed as an alternative explanation.

A literal reading of Noah's flood is more scientific than ECD.