Bill Napier paper on the YD boundary event

The Bill Napier paper pops up at http://arxiv.org/abs/1003.0744 and is provided by the Royal Astronomical Society (see earlier post and link to pdf). Basically, Bill Napier is saying the YD event was not caused by a comet impact or airburst as such but by thousands of comet fragments and debris, a signifcant difference to the model developed by Firestone and West et al. According to Napier, and consistent with the Clube and Napier theory developed in the 1980s and 1990s, the earth simply encountered a dense trail of material with an origin in a comet that regularly orbited through the inner solar system – and deposited a stream of debris and dust as it went round and round. The beauty of this idea is that the earth is able to warm as rapidly as it cooled – simply by emerging out of the stream of dust and debris, or losing that material over time from it’s upper atmosphere from where it had become trapped. This in turn caused an opaque sun – a weak amount of sunshine reaching the surface of the earth which was the major reason for the cooling. In other words, the cooling event itself was caused not by a comet, as such, but dust and debris trapped in the upper atmosphere – including sooty materia as a result of larger fragments of cometary material exploding in Tunguska fashion. In other words, it is not necessary to find huge amounts of ammonium in ice cores in comparison to that produced by the Tunguska event (see earlier post) as the airburst (s) were not exponentially larger, as such (but a multiplication of similar sized airbursts). Further, it seems that Napier perceives a connection with earlier events as in the Clube and Napier model the comet that was shedding it’s material arrived at least as early as 30,000 years ago. This means that it may have a connection with an event that witnessed the demise of the Neanderthals (or mutation – a possibility) and the death of large numbers of mammals around the world, particularly in Australia where these species became extinct at this point in time. In addition, the earth may have encountered the stream of material – there were probably more than one created on major outgassing events within the inner solar system – at the Oldest and Older Dryas events – as well as the Younger. The comet impact theory does not mention these other events as that would invoke too frequent a sequence of impact events – that their opponents would find unacceptable. However, if one impact event was feasible and then equally three or four such events in fairly close succession, over a period of 20 thousand years, is not necessarily remarkable. Only if you have not imagined the possibility previously.