glacial disasteroids, Hupervelocity impact of large ice ejecta

[JMARPL]

I've not been able to find studies of the process of impact for a very large (~1 cubic km) chunk of deep, relatively warm ice projected several hundred miles by an ETO striking a deep glacier obliquely.

Anyone know of such?
The circumstantial evidence of many such impacts is overwhelming but no capable scientists seem to have applied themselves to modelling this event.

jesl at Carolina dot net
(Jim Marple)

[JMARPL]

Most discouraging that none who scan this forum know of a study that produced a graphic illustration of the forces acting within an impacting mass of ice that was blasted from a glacier to land 800 miles to its southeast. (As occurred when an asteroid burrowed beneath a glacial tongue reaching down through the southern basin of Lake Michigan 11,000 years ago, the "Carolina Bays" phenomenon formative event.)

The complex combination of inertial forces within this impacting missile, generated by Coriolis forces in addition to the obvious ones, would certainly present a significant challenge to model-makers. Not on as large a scale as the initial impact, an event beautifully portrayed by the Sandia Lab with its Deep Impact simulation many years ago, but still a pretty complicated process. ETO (NEA) impact geomorphology, the most common and most spectacular of Earth's modification processes, has many such elements that deserve careful scrutiny.

Perhaps only the Sandia Lab's Teraflops could handle such a simulation, though, and it is kept busy with essential defense-space problems or politically correct environmentally-oriented ones. Matters such as a major alteration of landscapes now occupied by many thousand communities on the East Coast, Alaskan North Slope, Canadian Mackenzie Delta and in Nebraska may properly take second place to these concerns. After all, how many people care why the Tablelands survived overgrazing the destroyed millions of acres of fertile prairie or how groundwater flows convey fertilizer-pesticide-hog-chicken-cattle waste into the drinking water of many million people?

And it's probably best to let Australians, South Africans, Argentinians, Bolivians and Russians investigate their own versions of these gigantic hailstorms.

[JMARPL]

Discussion of the location of this ETO impact event with Prof Firestone of UC Berkeley led up to the following.

AGU Joint Assembly, May 2007

<http://www.agu.org/meetings/ja07/?content=search&show=detail&sessid=159>

"New Insights into Younger Dryas Climatic Instability, Mass Extinction, the Clovis People, and Extraterrestrial Impacts"

Tune in on the publications of these gents for a preview of seven blind wise men fondling an elephant.
Perhaps they'll connect the dots by then. recognize that Kenewick man was unfortunate enough to be directly under the path of that incoming missile that blakened the landscape for 1500 miles along the front of the continental glacier where a mammoth party was going on..

This is mere speculation, of course. My ancestral informants are kind of vague about this element of the broad picture. They've pointed me to only one bit of firm evidence that this small band of new immigrants was outstanding in their field 10,990 years when the disasteroid arrived. And it is pretty firm; 16 tons of Iron/metal now reposing at the entry of the American Museum of Natural History



jmarpl

[JMARPL]

CAROLINA BAY ORIGIN March 23, 2007
- Bladen Journal [NC] feature story

No one is quite sure what caused area's bay lakes
TIM WILKINS,EDITOR

Meteors? Comets? Prehistoric salmon? Ancient sea currents? No, these aren’t plot devices for the “Jurassic Park IV” screenplay; rather, these are some of the theories as to what formed the mysterious bay lakes - a chain of some 500,000 shallow lakes, bogs, and swampy depressions that range from New Jersey to Florida, but which are found in a particularly heavy concentration in North Carolina, especially here in Bladen County. .......

-----------------------------

EDITORIAL ADDITION/REVISION OF ABOVE May 9, 2007
http://www.bladenjournal.com/editorial/

[JMARPL]

I confess myself somewhat disappointed in the calibre of Physorg membership that none have agreed or disagreed with this editors perception of the Carolina Bay Mystery solution.

Can it be that none are aware of the effect this phenomenon has had upon Humanity?

Are the dozen-plus other instances of this 'instant' geomorphology unknown or just not of interest to members of this forum?

Seems to me that the possibiity of this many large meteorite impacts in very recent geologic history should at least bring a rebuttal by persons knowledgeable enough to present a brief statement of why they could not have occurred.

But then, perhaps most knowledgeable folks don't bother to scan the musings of non-experts, being content to perceive themselves as unique individuals who compose an intellectual elite that needs no outside input to solve Earth's mysteries. (Even though this major puzzle remains unsolved by them.)

[JMARPL]

A prof who denies membership in any 'intellectually elite' group tells me in direct communication that she has not given serious consideration to 'impactual geomorphology' because it was almost totally ignored by instuctors during her educational phase (in the '80s). While she understands the mechanics of comet/asteroid impact she has not given it much thought because it seemed too remote a possibility to be worth thinking about.

She realizes, of course, that this Earth is composed entirely of material delivered by meteoritic action. But the possibility that many relatively recent large mipacts have occurred, as I've discussed on various threads, was not brought up by her professors, who referred only to 'prehistoric collisions of great rarity'.

Perhaps this is why so few have commented re my conjecture that our globe has taken hits by large (greater than 1000-foot diameter) masses of extraterrestrial material about once each two thousand years on average.
It may be that most in the scientific world just assume that asteroid collisions, such as depicted in the movie "Deep Impact", are just too rare to deserve serious consideration. In fact it looks like we are many hundred times more likely to be killed by a major impact than we are to win a major lottery.

Astronaut Rusty Schweickart has not received significant Press attention for his strong recommendation that we immediately improve our capability to detect potential impactors, (variously termed ETOs - NEAs - ECOs) even though his arguments for this make excellent sense. It appears that editors prefer to keep us in the dark about this hazard, though perhaps their generally inadequate educational backgrounds denied them a clear view of the basics of Earth's formative process.

This astronaut also believes we should place communication equipment on large asteroids whose orbits bring them very close, to make their next visit to Earth's vicinity predictable, as the Japanese have done to one that they are studying. He notes that a close pass (some come closer than our Moon) could destabilize their orbit unpredicatably so that the next visit may be a direct hit. He has also pointed out that some arrived with no warning whatsoever, were not detected until they had already passed very near to Earth.

His recommendation that we place a 'machine' in orbit so that it can zip out to divert a potential killer asteroid, nudge it into a passing path, makes sense to me, as it does to quite a few prominent politicians and scientists. But apparently few in the fantasy worlds of Journalism and Hollywood agree. I've seen no effort to fully and fairly inform the public so that concerned citizens will push legislators toward acting prudently in re this matter.
Their campaign to politically assassinate our President, so that the criminal element of the private sector can gain total control over our election process through its army of liberal/socialist extremists, obviously has first priority. This agenda overrides common sense and personal integrity so to make a mockery of their promise to provide "all the news we need to know". (Our self-proclaimed
"intellectual elite" has made it clear that we only need to know what they want us to know.)

Perhaps large meteorite impacts are too rare to merit serious discussion. Perhaps not.
Looks like we'll have to just keep on hoping we stay lucky, do not see the World's food supply wiped out for a year so that only the very smart and wealthy survive. Some in my circle have suggested that this would suit those few hidden deceivers perfectly, that they have even taken steps to ensure their survival. But then, some in my circle also believe that dinosaurs developed from birds while others think it was vice versa.

We shall see, said a carpenter long ago as he picked up his hammer and saw.

jmarple - jesl at carolina dot net

[JMARPL]

How did meteorite impacts during the last *Wisconsin" glacial period affect global climate?

Recent 'astonishing' announcements have suggested that an incoming ET missile caused the Younger Dryas cooldown that lasted ~1300 years. (Considerable controversy persists about its precise date of beginning and end so these can be adjusted to suit the hypothesis.)
Of course, reporters are suckers for astonishing announcements, willing to grant headlines to anyone who invents a new slant on old data with a dab of new evidence, so that they can do a story.....

My perception of more than twenty large (1,000 foot-plus diameter) impactors in the past ~50,000 years is in need of careful research to trace the evidence back to the points of impact. (I've only two 'firm' sites and three probables out of the 14 events I've identified, though I know approximately where each one is.)
It seems likely to me that several of these events could have altered global climate somewhat significantly in either direction, depending upon their timing and point of impact into glacial ice or ocean currents.

My prime example, the Carolina Bay impact event, occurred between ~11,500 and ~11,000 BC according to a multitude of climate change records, with my preferred date 10,995 +-20.
But without a considerable amount of additional digging through records on five continents and piecing together data compiled by researchers looking into a wide variety of matters I cannot properly illustrate my perception of the role of impactual geomorphology in climate change. Hopefully I'll be granted an extension on my new lease on life to get this all done.

[Skeptical]

I find your idea rather interesting, but these landforms are hardly uniques to the US. See for example, hxxp://bbs.keyhole.com/ubb/showthreaded.php?Cat=0&Board=EarthNature&Number=367970 and hxxp://bbs.keyhole.com/ubb/showthreaded.php?Cat=0&Board=EarthNature&Number=366640

In addition, Wikipedia (I know, not always reliable, but since you are the one pursuing this line of thought, perhaps you can find other contrary sources) states:

"have been proposed to account for them, including action of sea currents when the area was under the ocean or the upwelling of ground water at a later time. The most acceptable theory within the earth sciences academic community is that a combination of processes including climate change, solution of subsurface material, wind erosion, and changes in the water table are responsible for the shapes and orientations of these ancient landforms. Proposals that they are impact craters created by a meteorite shower are criticized by scientists because of the lack of extraterrestrial material, absence of shocked quartz and "bedrock" deformation associated with larger bays, and extremely low ratio of depth to diameter of the larger bays. More information on this theory can be found at: Carolina Bays.

...

"As a result of studies of Carolina Bays in South Carolina involving detailed analysis of their stratigraphy and OSL dating of their rim deposits, they concluded that Carolina Bays are between 70,000 and 100,000 years old. For example, according to OSL dates the age of Flamingo Bay in South Carolina is about 108,700±10,900 BP and the age of adjacent Bay-40 is about 77,900±7,600 BP. Further south, another Carolina Bay, Big Bay, was found to be over 74,000 years old. Thus, as collaborated by the presence of alternating layers of sediments containing glacial and interstadial pollen found filling individual Carolina Bays, Carolina Bays are ancient landforms whose origin predate the end of the last glacial epoch by several tens of thousands of years to possibly over 100,000 years. Furthermore, the OSL dates indicate that the formation of the Carolina Bays was not an instantaneous event, but rather individual bays were formed at different times over a period of about 30,000 years. Any hypothesis of their formation will need to consider not only their age but also explain why Carolina Bays formed over a period of tens of thousands of years."

So, perhaps the idea that an impact around 12,900 years ago did occur, since there seems to be some evidence in support, the time frame for the Carolina Bays formation doesn't seem to follow in relation to such an impact. Furthermore, impacts wouldn't seem to be likely to have formed the Carolina Bays if they actually formed over a 30 year period - unless by some happenstance the earth go pelted repeatedly all from the exact same direction. Not impossible; not necessarily probable though.

hxxp://en.wikipedia.org/wiki/Carolina_bays
...

"As a result of studies of Carolina Bays in South Carolina involving detailed analysis of their stratigraphy and OSL dating of their rim deposits, they concluded that Carolina Bays are between 70,000 and 100,000 years old. For example, according to OSL dates the age of Flamingo Bay in South Carolina is about 108,700±10,900 BP and the age of adjacent Bay-40 is about 77,900±7,600 BP. Further south, another Carolina Bay, Big Bay, was found to be over 74,000 years old. Thus, as collaborated by the presence of alternating layers of sediments containing glacial and interstadial pollen found filling individual Carolina Bays, Carolina Bays are ancient landforms whose origin predate the end of the last glacial epoch by several tens of thousands of years to possibly over 100,000 years. Furthermore, the OSL dates indicate that the formation of the Carolina Bays was not an instantaneous event, but rather individual bays were formed at different times over a period of about 30,000 years. Any hypothesis of their formation will need to consider not only their age but also explain why Carolina Bays formed over a period of tens of thousands of years."

So, perhaps the idea that an impact around 12,900 years ago did occur, since there seems to be some evidence in support, the time frame for the Carolina Bays formation doesn't seem to follow in relation to such an impact. Furthermore, impacts wouldn't seem to be likely to have formed the Carolina Bays if they actually formed over a 30 year period - unless by some happenstance the earth go pelted repeatedly all from the exact same direction. Not impossible; not necessarily probable though.

[JMARPL]

Skeptical

I'm not much interested in the supposed impact around 12,900 years ago because i've seen no credible evidence of such an event and no indication of how it might have altered global climate.

My comments about Carolina Bays are perhaps too scattered in numerous threads to be easily comprehensible. I'm fishing for sources of information regarding the many intricate details.
Some of these:

- How might large masses of ice be accelerated to low hypervelocity without melting them?

- What would the internal workin's of impact by an ice spheroid 3/4 miles in diameter look like?

- The Younger Dryas episode was a return to the norm of glacial period temperatures so why bother to hypothesize that something triggered it?

My preferred scenario of asteroid impact has a ~11,500 to 11,000 BP range and I suggest that it ended the Younger Dryas, bringing on the Holocene that gave us a globe warm enough to populate explosively. The Carolina Bays are just a spinoff effect of this impact.

jmarp

This post has been edited by JMARPL on Jun 17 2007, 03:50 AM