Exploring abrupt climate change induced by comets and asteroids during human history


Restored from the library fire 1/11/20

 …the Destroyer

Dr. Hermann Burchard, a gentleman Tusk reader, insightful contributor, and emeritus mathematician, suggested I post a paper regarding the Shiva Structure off Mumbai, India, the little known brother of Chicxulub.  The question is whether it is a fraternal twin, or younger or older sibling. I say fraternal because it is certainly not identical. It is much larger.

I avoid posting much about the deep time impacts because it often seems to me to be as if from another planet. But it is not. And if we continue to realize how wrong we have been about ancient earth, perhaps we might learn some humility with respect to our far more recent past.

Take it away, Herm:




The abstract describes the geology of a 500 km crater off the coast of India, including impact signatures. This is THE MAJOR K/T impact, contrary to the public impression and lore that the impact was at Chicxulub.  Like the Ames OK structure it produces oil, about 10% of India’s demand, as of a few years ago.

Probably the two impacts occurred within minutes of each other, although Gerta Keller of Princeton U has claimed in the past that there was a 300,000 year interval.  She is an advocate of the controversial Morgan mantle plume theory, as many official geologists still are.

The abstract is an official publication of Chatterjee’s university, the Museum of Texas Tech University.  There is a text part and the crater image from gravity anomalies.  This image also appears in the article “Shiva crater” in WIKIPEDIA.

Herman B., etc

Download the PDF file .

14 Responses

  1. Hi All

    Swarm of asteroids in the remote past, swarm of meteoroids in the recent past, do not seem a good thing. Long period, short period, millions of years or thousands of years? Small, large, whole or bit by bit. When and how will be our next meeting?


  2. The Shiva paper (Chatterjee et al. 2006) covers a massive impact on India’s west coast, epoch 65 Myrs. What is extremely interesting here is a feature most likely in common with our more recent Yonger Dryas proposed event, although on a much lessor scale (contenental, not global) for the YD case, namely delivery of enough heat from hot reentering ejecta to light the surface on fire. All of the surface.

    Page 38 of the Shiva paper, right hand column, “Robertson et al. (2004) proposed that in infrared thermal pulse from a global rain of hot spherules splashed from teh KT impact was teh primary killing agent. According to this model, for several hours following the impact, the entire Earth was scorched with infrared radiation from reentering ejecta that would have killed unsheltered organisms directly and ignited global fires that consumed Earth’s forests and their dwellers.”

    Nice. Now that is a seriously unwelcome visitor. Even worse that smoking in bed.

    Lets pause for a moment and conider the smaller scale more recent case of the Younger Dryas Impact Hypothesis. If 5% to 7% of the continental US was covered by the sand blanket of the Carolina Bays, then something less than that would see a view factor of super heated sky over enough of there overhead to light fires on surfaces exposed to that sky.

    Something like 3% to 5% of the continental U.S. along the East coast, conservatively, could have been ignited by the reentering sand just before it fell to that same heated surface and emplace itself in the form of the Carolina Bays. Now that is before anything going on out west, just for readers more interested in Western US impact scarring.

    So to review:

    lots of ejecta all reentering at nearly the same time and covering a vast area of the upper atmosphere w/ thousands of degrees of heat as its SUBORBITAL velocity is absorbed by that atmosphere…

    … equals…

    …fire at the surface. (Wherever the view factor at the surface sees that heat over a large fraction of the sky’s area.)

    Realize that this has nothing to do with the approach velocity of the incoming bolide!

    This is the kinetic energy of the original bolide being redistributed over continental area in the form of suborbital exoatmospheric ejecta (still several km/sec but in all different directions radiating out from original impact site(s)). The killer kinetic is then transferred into heat upon reentry, and your roof and window shades just lit on fire because “the top of the sky” got too hot.

    Yes. The roof is on fire.

    And on the Eastern coastal low lands of the US back there at 12.9 ka give or take a few overturned nanoashes, things got a bit wacky.

    Before Mr. and Mrs. Clovis tried to secure their lawn furniture because the sky was falling (1600 cubic kilometers of sand rain over 5% of continental US all in around 15 minutes, Carolina Bays about to crush whatever is under the rims), they actually didn’t have time because their hair was on fire. Literally. And that was pretty much how thier day ended. Almost.

    They ran around on fire, through burning landscape, trying to figure out why the suddenly very bright sky that had just lit everything on fire was now just as suddenly getting very dark, and the wind was doing very wierd stuff, and their ears were popping like crazy from the insane pressure of that descending blanket of sand as it started blowing around all the burning stuff w/ hurricane-like wind arising in just a few minutes, suddenly the now very cold and very wet sand blanket (from the long descent through the entire atmosphere to the ground) crushed everything, probably putting out those fires over much of its new domain.

    And after that it still didn’t quiet down because there were shock waves in the air and tremors under foot, but no Clovis folks left to listen to Earth’s music any longer. Not on the East coast of North America. If anyone did survive that sand blanket train wreck, they probably couldn’t hear too well and had serious burn injuries.

    And then there were the food chain issues.

    Sounds bad. But purely a walk in the park compared to what was going on in the South West US on that fateful date. In that area Colvis or anyone else didn’t have much time to experience anything before they were vaporized or just plain incinerated where they stood, based on the surface scarring in those parts.

    They may have had time to crouch or dive to the ground. Or cover the kids they stood close to. Then Hell was unleashed, and their ashes were literally scattered to the wind. Bye bye. All in the time it takes to read this paragraph. Plain old fashioned conflagration. There, I said it.

    So why would normal scientists, geologists, politicians, theologins or anyone else have problems with a mounting pile of evidence that supports such proposed events in our very recent geologic past?

    I don’t get it. When I place my faith in Science, I must accept the truths uncovered in the Geologic record. Running frightened from this type of truth instead of facing it just means you will get your tail burned instead of your eyes blinded. Truth is truth. Accept it and move on.

    Acknowledge Murhpy’s law is the best way to avoid it.

    Do you want to have kids? Why bother?

    Until we figure this YD Impact out, and the revised nature of the threat that brings this nasty smoking company to our Earthly village so recently, I’m at a bit of a loss for reasons to procreate.

    ‘Just sayin’


  3. Hi folks

    I know perfectly that my research is not “academic,” I am aware of that.

    I believe that think of the YD as a local event or continental is due to lack of data for the academic “scientists” (although I am a doctor in another area and I am perfectly consistent with scientific principles in my research for the reasons of end of Pleistocene). USA, Mexico, Venezuela and other nooks and crannies of Europe have already presented the evidence for a global event.

    There was not a whole comet or pieces of 1 or 2 km, but millions of fragments of a large comet (>50km). The evidence for the model I’ve been investigating: craters (palaeolagoons) and impactites, make me believe that the event was global, the craters are all over the world. Also in this year I will investigate other Pleistocene lake (Lagoa Salgada), and dare I say with 100% chance I’ll find impactites there. So it has been with all the structures (palaeolagoons) that I have indicated.

    I know there are many people investigating in this direction too and I hope that soon some “academic” scientist take this hypothesis and “discover” that the event was global. Then, the hypothesis will be accepted by all.

    Anyway I will continue to present my own evidence.

    best regards

  4. Since I’ve been finding much the same kind of evidence that Pierson’s been finding, and in the same kinds of places, I’m thinkin’ he’s right.

    The trouble for the academics is that for decades now they’ve been working from the unquestioned assumption of a slow and steady, one bolide at a time impact flux. And in that assumption, they’ve painted themselves into a corner.

    The astronomical model cited in the Lake Cuitzeo paper is from Clube & Napier’s work on the Taurid complex. Specifically, ‘Paleolithic Extinctions, and The Taurid Complex’ by W.M. Napier.  And careful consideration of the kind of objects Clube & Napier are talking about leads one to heavily fragmented objects like Linear, https://dl.dropbox.com/u/2268163/CometLinear.jpg, or Schwassmann Wachmann 3, https://dl.dropbox.com/u/2268163/SW-3.jpg

    As the two objects above show, Clube & Napier are correct in their assessment that the breakup of comets is now a well recognized path to their destruction.

    But I find it curious that in spite of numerous examples of such dense clusters  of small fragments in short period, elliptical orbits that cross all the orbits of the planets of the inner solar system, no one wants to touch the question of what the impact of such a cluster would do. So far the only answer I’ve gotten is the opinion that a cluster impact event would be "highly unlikely".

    To date not one impact physicist has done any real science on the question. The fact that such objects commonly exist in the kinds of orbits they do means that occasionally planets of the inner solar system must get hit by them. But the problem is that for years NASA planetary scientists have been working from the unquestioned assumption of a slow, and steady, one bolide
    at a time, impact flux. And working from that assumption, they have been counting the number of craters in surfaces on the Moon, and Mars to estimate the ages of those surfaces. The trouble they face is that all it would take is for just one cluster of cometary fragments like either of those two comets to have hit a surface on one of those bodies anytime in the past few billion years to cause them to overestimate the age of that surface by many orders of magnitude.

    So to even acknowledge the possibility of a cluster impact event means throwing decades of work, and countless man hours of labor estimating the ages of planetary surfaces in the inner solar system right out the window. But to think that such common objects exist in the kind of orbits they do without the occasional celestial train wreck soon after the complete breakup of a comet is ludicrous.

    I also find it curious that in spite of how common such objects are, no one is willing to confront the question of what the consequences of a few hundred barge-loads of sand and gravel coming in at something like 30 kilometers per second might do of at all hit a concentrated area within a few seconds.

    They’ve done single bolide simulations to death. But what happens when a few thousand Tunguska class airbursts fall in a dense cluster so close together that only those fragments on the leading edge fall into cold atmosphere; the rest falling into the already superheated impact plumes of those that went before?

  5. Agreed,

    Dr. Boslough should crank out a barge load (x 1000) impact simulation, not necessarily thousands of Tunguska class airbursts, but enough mass and in a heirarchy-fragmented distribution of sizes, and in a streaming arrival scenario, to see what happens to the surface temp/conditions under it all, how much of it reaches the surface if any, and generally if it starts to look like what is being found in the imprint (all over Earth) from the Younger Dryas Boundary Layer.

    I am also very curious about timing of the arrival of streams of fragmeted bolide. If the rates of variation of the orbital parameters are as slow as Napier suggests, then the chances are that Earth hit the stream more than once.

    Not only that but we don’t know the exact structure that the stream(s) may assume. This means that within the resolution of the various goelogic dating means, there could have been more than one or even several streaming impact events, so how would that figure in. If they were 6 months or 12 months apart, it could have been one hemisphere getting hit in one encounter and a different hemisphere in the next, etc.

    It is not out of the question that a continental burning from one stream encounter could still be going on 6 months (even one year?) later when another stream encounter happens.

    Perhaps each encounter is with a different section of the bolide cluster, so each event has its own characteristic, such as overall mass of impact, mean particle size, average angle of approach, not to mention different surface characteristic under the comet rain, different weather or average depth and temp of atmosphere encountered (tropics vs. polar), etc.

    Plenty to look at. Dr. Bolsough should get busy, perhapse starting by studying Napier….


  6. Mark Boslough is the quintessential skeptical scientist. First he’s got to be convinced it happened, or can happen, before he’s gonna put a lot of effort into working up a numerical model. And as one of the chief skeptics of the YDIH, the proof will have to be a lot more robust than it has been so far. It’s ironic that it just may be that the very geomorphology that proves his ablative airburst models might wind up being the planetary scarring that proves the YDIH once and for all.

    It’s not hard to find burnt facies, and geology that’s consistent with an airburst event. Heck there’s a whole mountain of pristine non-volcanogenic burnt facies less than five miles from my home. But getting reliable geochronology for that scarring that’s consistent with the YDIH is a different problem.

    As for work on the timing of debris streams of the Taurids, Bill Napier’s not the only one who’s been working on that. So in addition to Clube & Napier’s books, ‘The Cosmic Serpent’ and ‘The Cosmic Winter’. Duncan Steel’s ‘Rogue Asteroids and Doomsday Comets’ is a must read.

    And in the peer reviewed literature arena, along with Bill Napier’s Paleolithic Extinctions and the Taurid Complex you should read ‘The Structure and Evolution of the Taurid Complex’ by D. I. Steel et al.

  7. Hi all

    I imagine that the body of fragments distributed in the orbit of extinct comet could hit the Earth for several hours and days, depending on the dispersion of fragments in space.

    Current meteor showers can have their peaks in a few hours and be seen only in one hemisphere of the Earth. The meteor showers can last days, even weeks.

    Yes my feeling also is that the earth’s orbit crossed the orbit of the fragments at different times, in either ascending or descending orbit, reaching differently terrestrial hemispheres, speeds and different explosive potential effects. Intervals could have been a short period, months, years, or long period, centuries, millennia? Would the orbit be clean? Or meteoroids are still active? It has happened! Can it happen again?


  8. The D. I. Steel et al. paper investigates the possibility that the Taurid Complex (TC) of metieor streams all originated from a single large progenitor.

    They use a selection of known orbits of TC objects, along with backward time integration (a common tool in astro problem solving), some assumptions about fragmentation velocities and orbital locations of those fragmentation events (i.e. perihelion vs. apehelion), all to propose a single historic source object to that group of Sun orbiting objects.

    Their paper uses some restrictive assumptions which are completely reasonable and well explained, so no magic or surprises.

    The value of this invetigation to the Younger Dryas impact hypothesis is largely indirect, but may also be a detractor in the greater picture.

    Whatever hit Earth approx 13 ka ago is no longer in orbit. So for the really useful data to come out of TC study, it would have to be where are the gaps in the TC streams that would otherwise be where Earth has swept out those elements of the TC, at the specific date(s) identified as the YD Lower Boundary.

    Unfortunately the work is far too general to point to such specifics. This situation may change as time and science march forward, and that will largely be the direction of such efforts going forward.

    They model gravity as the main orbital purturbation acting on the Taurid Complex to get a rough idea of rates of change of orbital parameters, a perfectly reasonable approach to the first pass at such a study.

    To actually find a gap in the Taurids where Earth swept through at the proposed YDLB epoch, much finer detail in the perturbational analysis would be required, among other things. Fragmentation mechanisms are another area needing more detailed input to get better detail in the output of that sort of model.

    So it seems they are headed in the right direction.

    The larger problem as I see it, is that the assumption of the TC as the YD impact perpetrator is placing all eggs in one basket. Because whatever hit Earth is no longer out there, we don’t really know orbit details, and may never know.

    Meanwhile all other potential perpetrators are still at large. Danger.

    What we really need is another generation of sky survey, down to a lower limit of approx 50 meter diameter objects or less, to identify threats that we now understand can cause events like Tunguska, and are MUCH more common than the 1000 meter diameter minimum size objects sought out in the earlier sky survey.

    Such an updated survey would most likely identify more TC objects as well as plenty of stuff in other orbits, any of which would really mess things up here on Earth if the orbits and timing ‘fall’ within specific values.


  9. The significance of the Taurid progenitor object entering the inner solar system 20,000 to 30,000 YA, and its subsequent breakup over many millennia is that those progressive breakups would have comfortably straddled the YD. This is pretty much the gist of Napier’s paper, and the reason why the YDB team adopted it as the preferred astronomical model for the YD event. There is also a strong possibility that the collapse of many Bronze Age civilizations is related to impact storms of comets from the Taurid Complex.

    As for “all of the eggs in one basket”, one should keep in mind that there are still significant quantities of material left in the TC. And probably a few large undiscovered fragments left that are capable of producing an extinction level impact event.

    There are still many many eggs left in that basket. And this world hasn’t seen the last catastrophic impact from it.

  10. Due to Michael Davias’ outstanding work on the possible formation date of the Carolina Bays based on very well dated river terraces over which the CBays lie (& more importantly where they don’t), any catastrophic (single event) formation of the CBays would have happened in the 130ka to 150 Kia range, ruling out any link between the CBays and any Younger Dryas lower boundary event.


    Davias’ tireless and outstanding effort strongly suggests a shallow angle strike of a massive bolide on the Laurentide Ice Sheet. Opponents of this concept don’t like the apparent lack of surface scar or “crater”. Those opponents refuse to accept that the Saginaw basin of lower Michigan state and all of its underlying geomorphology can be interpreted as a large, complex crater structure complete with central uplift, plenty of deep subsurface fracturing and other attractive attributes for oil prospecting. I have discussed this with Dr. Burchard and he agrees.

    Opponents don’t like to think outside the traditional box. They are also at a loss so far to describe the signature that such an impact would leave on the surface (Michigan landscape) under two miles or so of ice that was likely in place during Davias’ proposed CBay formation epoch. That is why I am on a mission to write an analytical description for shallow angle impact. Recent advances in impact science point to compelling facts which are very clear. Those recent advances also leave out some critical details, making an analytic Shallow Angle effort a clear and simple necessity….

    In a shallow angle strike, most of the bolide’s mass skips off the surface and flies away, a radically different scenario from steeper angle impacts where all kinetic energy is instantly absorbed at the impact site, starting the cratering process. (See Melosh et al “Fate of the Projectile”.)

    The relatively “cold” temp of the Shallow Angle strike case is radically different from its steeper angle cousins, and so WE SHOULD EXPECT RADICALLY DIFFERENT SIGNATURES as the result of such Shallow Angle impact cases. Clearly. But peak temperature of the impact event is not the only critically important difference of the Shallow Angle strike….

    The dispersive spray of liquified bolide as it “skips” off the surface is more important in this case due to the epoch which Mr. Davias now proposes. For the Shallow Angle case, a MAJORITY of the mass of the bolide (& the killer Kinetic Energy of that mass) skips away back out into space, into a range of Earth-crossing orbits, with a range of orbital periods. Interestingly some lessor fraction of that skip “spray-jet” mass actually departs the impact scene going faster than it approached, so there is quite a wide range of departure conditions, which define all the new Earth crossing orbits.

    Mr. Davias’ proposed epoch of roughly 140ka for the massive Shallow Angle ice sheet strike is a perfect primer for lots of shower events over a long duration afterward, which could easily explain the Younger Dryas Impact as well as plenty of others over time from then till now AND into the future….

    Recently I had the dubious privilege to see the 50 ton chunk of Atlantic coral reef that sits hundreds of feet above sea level on a plateau in the Dominican Republic, presumably lofted there by a mega-Tusnami. It’s very real. So is the current risk of cosmic impact, which absolutely needs further and more accurate characterization (!), if we are to survive as a species in our sometimes violent cosmic neighborhood.

    The thing that has changed the most over that entire period in history is the extreme population that has now settled around the rim of that and all other Ocean basins of our planetary house. Cosmic impacts are a known geologic process, that much has not changed. They have happened and they will happen again. It’s the extend of potential death and damage that has increased. This is why we need better characterization of risk from local traffic in our cosmic neighborhood. There is far too much at stake to keep thinking only inside the box.

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