Recent Developments in the Analysis of the Black Mat Layer and Cosmic Impact at 12.8 ka

[knocker]

 

Abstract

Recent analyses of sediment samples from “black mat†sites in South America and Europe support previous interpretations of an ET impact event that reversed the Late Glacial demise of LGM ice during the Bølling Allerød warming, resulting in a resurgence of ice termed the Younger Dryas (YD) cooling episode. The breakup or impact of a cosmic vehicle at the YD boundary coincides with the onset of a 1-kyr long interval of glacial resurgence, one of the most studied events of the Late Pleistocene. New analytical databases reveal a corpus of data indicating that the cosmic impact was a real event, most possibly a cosmic airburst from Earth's encounter with the Taurid Complex comet or unknown asteroid, an event that led to cosmic fragments exploding interhemispherically over widely dispersed areas, including the northern Andes of Venezuela and the Alps on the Italian/French frontier. While the databases in the two areas differ somewhat, the overall interpretation is that microtextural evidence in weathering rinds and in sands of associated paleosols and glaciofluvial deposits carry undeniable attributes of melted glassy carbon and Fe spherules, planar deformation features, shock-melted and contorted quartz, occasional transition and platinum metals, and brecciated and impacted minerals of diverse lithologies. In concert with other black mat localities in the Western USA, the Netherlands, coastal France, Syria, Central Asia, Peru, Argentina and Mexico, it appears that a widespread cosmic impact by an asteroid or comet is responsible for deposition of the black mat at the onset of the YD glacial event. Whether or not the impact caused a 1-kyr interval of glacial climate depends upon whether or not the Earth had multiple centuries-long episodic encounters with the Taurid Complex or asteroid remnants; impact-related changes in microclimates sustained climatic forcing sufficient to maintain positive mass balances in the reformed ice; and/or inertia in the Atlantic thermohaline circulation system persisted for 1 kyr.

 

http://onlinelibrary.wiley.com/doi/10.1111/geoa.12033/abstract

[Gray-Wolf]

This type of event is something the Ison chatter had me wondering about.

 

If we had a large/very large 'first time visitor' to the inner Solar System then any 'debris field' it left on it's passing would surely, like other regular Meteor showers, be an annual event until the debris are used up?

 

If the event that propelled the object into the inner solar system was large enough then could it not drive collisions/multiple collisions that then propel maybe multiple objects into the inner solar system instead of just one? Maybe one very large body, that then fragments as it nears the sun, leading to a dense field of fragments/dust?

 

When the NASA bod first mentioned the chance of an early start to the noctilucent season, due to our upcoming encounter with the debris field left by Ison as it passed our orbital path, then I had to wonder at how it could impact Earths incoming energy budget ( trapping in heat or reflecting energy away before it entered our energy budget?) I also found myself wondering if 'timings' of such events was important? Would a mid northern summer glut of noctilucents have a bigger impact than a mid northern winter one?

 

Couple that with a yearly bombardment with airburst/impactors and you probably do have the ingredients for an extended period of climate disruption?

 

As for the Y.D. climate impacts? I suppose just emerging from an ice age does not leave the planet best positioned to 'shrug off' such climate peturbations? The remaining ice sheets would not find it too hard to re-grow and have the albedo impacts compound any atmospheric albedo anom?

 

In some ways the impact observations lessens any threat of T.H. shutdown due to meltwater pulses driving such big changes ( seeing as we don't see such from other emergence into interglacials?) so the future 'risks' of a N.European 'cooldown' ,as we warm further, must also be reduced? 

[Bobby]

If we had a large/very large 'first time visitor' to the inner Solar System then any 'debris field' it left on it's passing would surely, like other regular Meteor showers, be an annual event until the debris are used up?

 

If the event that propelled the object into the inner solar system was large enough then could it not drive collisions/multiple collisions that then propel maybe multiple objects into the inner solar system instead of just one? Maybe one very large body, that then fragments as it nears the sun, leading to a dense field of fragments/dust?

 

When the NASA bod first mentioned the chance of an early start to the noctilucent season, due to our upcoming encounter with the debris field left by Ison as it passed our orbital path, then I had to wonder at how it could impact Earths incoming energy budget ( trapping in heat or reflecting energy away before it entered our energy budget?) I also found myself wondering if 'timings' of such events was important? Would a mid northern summer glut of noctilucents have a bigger impact than a mid northern winter one?

 

Couple that with a yearly bombardment with airburst/impactors and you probably do have the ingredients for an extended period of climate disruption?

 

As for the Y.D. climate impacts? I suppose just emerging from an ice age does not leave the planet best positioned to 'shrug off' such climate peturbations? The remaining ice sheets would not find it too hard to re-grow and have the albedo impacts compound any atmospheric albedo anom?

 

In some ways the impact observations lessens any threat of T.H. shutdown due to meltwater pulses driving such big changes ( seeing as we don't see such from other emergence into interglacials?) so the future 'risks' of a N.European 'cooldown' ,as we warm further, must also be reduced? 

 

If the tail passed through Earth's orbit... but that doesn't happen with all comets. We may pass through ISON's tail in January but only a handful of extra shooting stars each night for a few days are expected. The tail is extremely diffuse dust and we will be passing through it for only a short time, the amount of mass entering into the Earth would surely be very small (as likely with all meteor showers like the geminds, perseids etc). Your average fireball which are regular events would probably bring far more cosmic material. The remants of ISON won't be heading to Earth as they will continue the original orbit passing about 40 million miles at its closest to Earth above our N pole.

 

Cosmic material entering into our atmosphere may cause Noctilucent clouds but not due to ISON, the amount is miniscule compared to the annual stuff we get from meteors, general background dust/small fragments that burn up in the upper atmosphere constantly. Perhaps if a comet passed very close to the Earth like Comet Sliding Spring which is expected to skim Mars next year then that could have a significant effect on Noctilucent clouds, maybe even the climate. It'll be interesting to see what happens on Mars next year, the comet could be so close the coma may envelop Mars...

 

If the event that propelled the object into the inner solar system was large enough then could it not drive collisions/multiple collisions that then propel maybe multiple objects into the inner solar system instead of just one? Maybe one very large body, that then fragments as it nears the sun, leading to a dense field of fragments/dust?

 

There is the Nemesis theory, the idea there exists a brown dwarf star orbiting our sun an eccentric orbit every 25-30 million years - each time it passes close to our solar system its gravity distrupts comets in the Oort cloud, sending millions, billions of them into the inner solar system, odds are one of these would be expected to hit Earth. The theory comes from the fact extinction events seem to come in a regular pattern of 25-30 million years, appears to be clusterings of impact craters following the pattern too.

 

http://www.lbl.gov/Science-Articles/Archive/extinctions-nemesis.html

http://swanson.bol.ucla.edu/

http://www.thekeyboard.org.uk/Our%20Nemesis.htm

http://muller.lbl.gov/pages/lbl-nem.htm

 

I wonder when our next 'turn' is??

[frogesque]

So, in yer basic English: Something(s?) went bang in the atmoshphere about 12,000years ago (give or take a few days) and deposited a load of cosmic soot worldwide.

 

Just love geologyspeak! Have I got the gist of it though?