Kerr Watch

Elapsed time since Richard Kerr failed to inform his Science readers of the confirmation of nanodiamonds at the YDB: 6 years, 3 months, and 3 days

Now Available: Pigati, Wetlands and Volcanoes

  • Thanks for posting this. Meanwhile, a comment on Astrobob indicates another lady found a 17 gram piece of the Sutter’s Hill meteorite fall in the park today, not sure which one, Lotus village park or the big state park. It shouldn’t take too long to check out most of the village streets.

    I’m wondering how many people will be out there looking?

  • E.P. Grondine

    I want to make a few comments on combustion in impacts.

    We pretty much know that for a 60 meter Tunguska class object, the infra-red from the airburst is sufficient to set vegetation on fire, but those flames are extinguished by the airburst’s blast wave.

    We know from Libyan Desert Glass that some classes of impacts can generate extremely high surface temperatures.

    We know from Rio Cuarto that the infra-red thrown off by a tangential impactor is sufficient to set the surface under its flight path on fire.

    The same phenomena has been calculated to be the result of the entry of pellets from a hard impactor fragmented near the Earth. In other words, if you have enough meteors entering the Earth’s atmosphere at once, then the infra-red can be sufficient to generate surface combustion temperatures.

    Another cause of combustion in impacts is the landing of bediasites thrown out from a large impact.

    Two large structures which may be associated with the HSIE are Ilturalde and Lloydsminster. Neither has been examined closely to see if they date from 10,900 BCE. Further, neither has been examined for type of impactor or angle and direction of entry.

    A logical search pattern would be to treat these as locations is an elliptical debris field, and look for other astroblemes along that field’s axis.

    Whether the resulting combustion products accumulate in wetlands is a question I have to leave for others.

    I will note is this regard that the Pleistocene climate was far different than the YD climate and the Holocene climate.

  • E.P. Grondine

    Now we come to the question of where exactly upper atmospheric impact dust, bediasites, and combustion products are going to “pool” or concentrate.

    If they are dry, clearly most of these are capable of being lofted by winds. If not dry, in other words if they are wet, they will adhere or cohere.

    Assuming a far higher rate of cometary impact than is commonly held (an estimate without any foundation other than known to be flawed studies from the 1960’s), then it should come as no surprise that impact products might accumulate in standing water, and accumulate in pools of standing water quite often over time.

    Its the concentrations of them that might be indicative of the sizes, locations, and dates of larger impacts.

  • E.P. Grondine

    Some Addenda –

    To my short list of sources of combustion in impact, I need to add the infra-red from a large surface impactor’s “pipe”.

    “Pipe” – while it is commonly visualized that a large surface impact generates a “plume” like that of a nuclear explosion, in point of fact there is a vacuum left behind by a large impactors passage through the Earth’s atmosphere.

    The mechanics of large hypervelocity surface impacts resemble those of an armor piercing shell, which explains the mechanism by which tektites are formed.

    One of the most surprising results is
    that the impact pipe looks like a funnel when seen from a very great distance, as the Earth’s atmosphere grows less dense with altitude.

  • Steve Garcia

    I was reading this paper and thought I recognized a date.

    Pigati wrote:

    [Abstract]…Iridium concentrations in bulk sediment (Irbs) ranged from 0
    to 2.5 ppb (Fig. 3; Dataset S3), similar to levels found by Firestone et al. (1). (Note that Irbs was measured on bulk samples
    of 10 g or larger to avoid any “nugget effects”; ref. 13). The highest concentrations were found in an 8.2 ka black mat at Tilomonte
    (1.200.21 ppb), a 10.6 ka mat at Quebrada Agua de Cascabel
    (QAC 4; 0.860.21 ppb), a 13.0 ka mat at El Salto 1 (1.65 
    0.10 ppb), and a >40 ka mat at Rio Salado (2.510.15 ppb).

    The approach taken here avoids most of these issues in that a single event cannot be invoked to explain the presence of the markers studied here in deposits dating from approximately 6 to more than 40 ka in both North and South America. Our data clearly show that elevated concentrations of some of the markers put forth by Firestone et al. (1) as evidence of an ET impact event, specifically iridium in bulk and magnetic sediments, magnetic spherules, and titanomagnetite grains, are common within or at the base of black mats, regardless of age or location. These results suggest that the markers are likely concentrated by processes inherent to wetland systems and are not the result of a catastrophic impact event.

    The approach taken here avoids most of these issues in that a single event cannot be invoked to explain the presence of the markers studied here in deposits dating from approximately 6 to more than 40 ka in both North and South America. Our data clearly show that elevated concentrations of some of the markers put forth by Firestone et al. (1) as evidence of an ET impact event, specifically iridium in bulk and magnetic sediments, magnetic spherules, and titanomagnetite grains, are common within or at the base of black mats, regardless of age or location. These results suggest that the markers are likely concentrated by processes inherent to wetland systems and are not the result of a catastrophic impact event.

    Note the dates. 8.2 kya, 10.6 kya, 13.0 kya, and >40kya.

    I present here something I believe Ed and George know and maybe others here, too:

    Kobashi et al 2007 – Precise timing and characterization of abrupt climate change 8200 years ago from air trapped in polar ice
    http://www.science.oregonstate.edu/~brooke/Recent_Publications_files/Kobashi%20et%20al._2007.pdf

    Abstract
    How fast and how much climate can change has significant implications for concerns about future climate changes and their potential impacts on society. An abrupt climate change 8200 years ago (8.2ka event) provides a test case to understand possible future climatic variability. Here, methane concentration (taken as an indicator for terrestrial hydrology) and nitrogen isotopes(Greenland temperature) in trapped air in a Greenland ice core (GISP2) are employed to scrutinize the evolution of the 8.2ka event. The synchronous change in methane and nitrogen implies that the 8.2ka event was a synchronous event (within 74 years) at a hemispheric scale, as indicated by recent climate model results [Legrande, A. N., Schmidt, G. A., Shindell, D. T., Field, C. V., Miller, R. L., Koch, D. M., Faluvegi, G., Hoffmann, G., 2006. Consistentsimulations of multiple proxy responses to an abrupt climate change event. Proceedings of the National Academy of Sciences 103, 837–842]. The event began with a large-scale general cooling and drying around ~8175+/-30 years BP (Before Present, where Present is 1950 AD). Greenland temperature cooled by 3.3+/-1.1°C (decadal average) in less than ~20 years, and atmospheric methane concentration decreased by ~80+/-25 ppb over ~40 years, corresponding to a 15+/-5% emission reduction. Hemispheric scale cooling and drying, inferred from many paleoclimate proxies, likely contributed to this emission reduction.In central Greenland, the coldest period lasted for ~60 years, interrupted by a milder interval of a few decades, and temperature subsequently warmed in several steps over ~70 years. The total duration of the 8.2ka event was roughly 150 years.

    I don’t know about anybody else, but to me that sounds like Pigati has pointed to exactly the right time, connecting one other black mat to an abrupt climate event, one that came on every bit as suddenly as the YD. To me the confluence of these papers suggests that both had the same type of event cause them.

    This paper makes no mention of any black mat anywhere. Pigati et al provides that.

    In climatic or geological terms, the “~20 years” onset of the 8.2 kya event is essentially instantly.

    At http://www.ncdc.noaa.gov/paleo/abrupt/data5.html there is a NOAA discussion of the “8.2 kya event”, with nice maps and info. Notably the map shows (and I am certain the relevant papers discuss) “cold” and “dry”; the two go hand in hand with stadials, but this event was too short to be called a stadial, I would think.

    Hilariously, IMHO, they drag out the old Lake Agassiz ice dam break as a possible trigger for the 8.2 kya event. That event sure does get around for something for which there is NO physical evidence.

    What to think of this confluence of these papers and this evidence?

    On the surface, it seems we can conjecture the following (at the risk of being a greedy reductionist!):

    1. That whatever happened at 12.8 kya is likely the same thing that happened at 8.2 kya.

    2. Pigati’s 10.6 kya and >40 kya black mats may indicate the same thing.

    3. That the main difference between the two events at 12.8 kya and 8.2 kya is how long the effects lasted. In one case it was 1300 years, and the other was 150 years. This suggests that something extended one and that that something did not happen to extend the other.

    4. It might behoove us to look into that 10.6 kya event.

    All this brings up the subject of fairly frequent such events. 12.8 kya to 10.6 is 2.2 kya. 10.6 kya to 8.2 is 2.4 kya. If impact events it would stand astronomers and their pontificated impact frequencies on their heads.

  • Steve Garcia

    The NOAA article has EIGHT links to datasets relating to the 8.2 kya event. The data derive from Minnesota (2), Cariaco Basin, Greenland (2), Costa Rica, Germany, and the North Atlantic. Nicely spread around and roughly the same regions as the YDB evidence.

  • Steve Garcia

    I know why they look at the North Atlantic. That is where the ice rafted rocks of the Heinrich events were dropped, so they are trying to connect the two, in order to establish a N Atlantic shutdown as the cause (as opposed to the end effect) within gradualisms strictures. Shades of Wally Broeker.

  • Steve Garcia

    I think it would behoove the YDB team to look closely at the 8.2 kya event sites and data, and the evidence itself, too.

  • Steve Garcia

    Hahaha –

    The one thing that science prides itself on is its ability to predict results. I looked at those dates and thought about our slowly developing idea that the YD was not the only impact and thought, “Well, if it is true, then the same sort of evidence should be showing up at the other times suspected. Let’s see if we can work this backward and see if Pigati hasn’t inadvertently given us some terrific evidence. If our conjecture is true, then those other black mats come from impacts, too – NOT just from run-of-the-mill wetlands. Do those dates tie into any abrupt climate events?”

    BINGO. At least one bingo. Connection made. Prediction held true. Luck? Coincidence? Perhaps. But the 8.2 kya event is NAILED time-wise, and Pigati walked us right into that exact time.

  • Steve Garcia

    Right now Pigati’s conclusions are on less solid ground than he thinks.

  • Hello to all

    It seems that this kind of event is a lot more common.

    One of the most important events in human history, the 4.2 kya event, when great civilizations around the world collapsed into anarchy and social chaos. A climate cooling and widespread aridification began, lowering agricultural food production and human living conditions. A major impact features as observed by historical Sumerian eyewitnesses.

    http://www.knowledgeminer.eu/store/eoo_paper.html

    And the next?

    regards
    pierson