[meteorite-list] vast geoablation in Argentina, craters from SW to NE -- Cox re Boslough bursts: Rich Murray 2011.07.31

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Sun, 31 Jul 2011 18:11:56 -0500
Message-ID: <47F5F303CF2A42AA860AD3B7875A2337_at_ATARIENGINE2>

While no one is going to address all of these points from
this long post, I'll tackle one --- the Libyan Desert Glass:

> Low Altitude Airburst... from a ~100 meter diameter
> NEO melted sand into glass across a region about 10 km
> in diameter during Libyan Desert Glass impact...
> 35 million years ago.

The problem is that when walks the incredible inferno
of this part of the Sahara and its vast sands, one thinks:
how could this sand have been fused in glass? And that
is a DEAD WRONG question.

35 to 28 million years ago this area, and tens of thousands
of square miles around it, were UNDERWATER. These low
desert basins were a lacrustine environment -- shallow
waters, with an occasional patch of swampy ground (on
what are now hilltops).

When I say "shallow," I mean 100 meters more or less.
Underlying the LDG area is sandstone, the upper layers
of which is younger than the LDG, sandstone that
formed at those lake bottoms. The LDG is found along
the former shoreline in one area of the SW shore of the
Depression.

There's a nice Google map of those lacrustine basins at:
http://www.inognidove.it/egypt/

If the LDG formed from dry desert sand by incredible
heat from an airburst or an impact, it had to have
happened somewhere else and the LDG was moved
here, or they are yellow tektites from the same event
as other tektites their age or another event of similar
age elsewhere.

If the Belize tektites are "australites" in age, they were
 tossed a long way. The LDG could have been tossed
from Chesapeake Bay, which BTW was a lot closer to
Egypt in the Oligocene than it is now, as the Atlantic
was narrower, not that great distances matter much
to tektites.

I would give a bunch of references, but since I've posted
about this twice over the last ten years and put lots of
citations in them, just check the List Archives if you
want references.

Here's one, though.

"The 1981 expedition... established that the present
mass of glass exceeds 14,000,000 tons; the original
mass of glass may have been 10,000 times greater,
or 140,000,000,000 tons." [units converted]
http://www.sciencedirect.com/science/article/pii/0022309384901777
140 billion tons of glass is one heck of a lot of glass
for one little 100-meter NEO to whip up a batch of.
Let's see. First you have to boil 10-100 meters of
water off, then dry out the wet bottoms and all
the sand, then you have to melt 140,000,000,000
tons of it.

I think you need a bigger bang... even to toss it there.


Sterling K. Webb
----------------------------------------------------------------------------
----- Original Message -----
From: "Rich Murray" <rmforall at gmail.com>
To: <meteorite-list at meteoritecentral.com>; "Rich Murray"
<rmforall at gmail.com>; "Rich Murray" <rmforall at comcast.net>
Sent: Sunday, July 31, 2011 2:11 PM
Subject: [meteorite-list] vast geoablation in Argentina, craters from SW
to NE -- Cox re Boslough bursts: Rich Murray 2011.07.31


vast geoablation in Argentina, craters from SW to NE -- Cox re
Boslough bursts: Rich Murray 2011.07.31
http://rmforall.blogspot.com/2011_07_01_archive.htm
Sunday, July 31, 2011
[ at end of each long page, click on Older Posts ]
http://groups.yahoo.com/group/astrodeep/message/91
[ you may have to Copy and Paste URLs into your browser ]


http://www.bibliotecapleyades.net/ciencia/ciencia_asteroids_comets27.htm

Something Wicked This Way Comes
Meteor
A New Kind of Catastrophe
by Dennis Cox 09 April 2011
from SOTT Website

"...At Sandia Labs, Mark Boslough used their 'Red Storm' supercomputer
to
simulate the airburst and impact of a 120-meter diameter stony
asteroid.

[ http://www.space.com/2295-supercomputer-takes-cosmic-threat.html ]

The colors in the simulation we see in the below video, are graded by
temperature.
White = 5800?K - 5527?C
Red = 2000?K - 1727?C

http://www.youtube.com/watch?v=Gr7i33UhmC8&feature=player_embedded

Simulation of an asteroid exploding in Earth's atmosphere, taking into
account the momentum.
[ 21 second video ]

Dr Boslough tells us that, in it, we see the ablated meteoritic vapor
mixes with the atmosphere to form an opaque fireball with a
temperature of thousands of degrees.

As it hits the ground, the hot vapor cloud expands to a diameter of 10
km within seconds, remaining in contact with the surface, with
velocities of several 100m/s. And at temperatures exceeding the
melting temperature of quartz for more than 20 seconds.

Moreover, the air speed behind the blast wave exceeds several hundred
meters per second during this time.

For comparison, an ordinary oxy-acetylene cutting torch in a steel
shop uses a thin stream of hot gases at only about 900?C. and 40 psi
to cut steel.

The speed of that stream of hot gasses is only a little bit more than
a stiff breeze. But that's all it takes to turn solid iron into a
melted, aerosol, spray. And to blow it away in runnels of melt into
heaps of slag.

Dr Boslough tells us that:

"Simulations suggest strong coupling of thermal radiation to the
ground, and efficient ablation of the resulting melt by the
high-velocity shear flow."

We have its existence predicted in peer reviewed literature.

But so far I haven't heard anyone attempt to describe the form that
such geo-ablative melt might take as it is emplaced. While in motion,
any ablated materials from a large, geo-ablative, airburst like that
would be in atmospheric suspension, in a density current similar to a
pyroclastic flow. And when everything comes to rest, the resulting
rock form might be visually indistinguishable from ordinary volcanic
tuff, or ignimbrite. If so, we face a conundrum in the Earth sciences.

Because it has always been assumed without question that only
terrestrial volcanism can melt the rocks of the Earth, or produce
'Tuff'.

If very large airbursts can produce formations of geo-ablative melt,
instead of craters, then almost every last pebble of airburst melt on
this fair world of ours has been mis-defined as volcanogenic.

Astronomers Victor Clube, and William Napier, had been talking about
the giant comet they described as the progenitor of the Taurid Complex
since 1982, in their book The Cosmic Serpent.

But no one had connected the dots, and put the Younger Dryas comet,
and the Taurid Progenitor together. Except in private, speculative,
emails, and letters. And to the best of my knowledge there was nothing
in refereed literature.

http://dl.dropbox.com/u/2268163/Paleolithic%20extinctions.pdf 7 page

Then, in early 2010 Professor Napier published a paper in the Journal
Monthly Notices of the Royal Astronomical Society titled, "Paleolithic
extinctions and the Taurid Complex," -- in it we read:

"The proposition that an exceptionally large comet has been undergoing
disintegration in the inner planetary system goes back over 40 years
(Whipple 1967), and the evidence for the hypothesis has accumulated to
the point where it seems compelling.

Radio and visual meteor data show that the zodiacal cloud is dominated
by a broad stream of largely cometary material which incorporates an
ancient, dispersed system of related meteor streams.

Embedded within this system are significant numbers of large NEOs,
including Comet Encke. Replenishment of the zodiacal cloud is
sporadic, with the current cloud being substantially over-massive in
relation to current sources. The system is most easily understood as
due to the injection and continuing disintegration of a comet 50-100
km in diameter.

The fragmentation of comets is now recognized as a major route of
their disintegration, and this is consistent with the numerous
sub-streams and co-moving observed in the Taurid complex. The probable
epoch of injection of this large comet, ~20-30 kyr ago, comfortably
straddles the 12.9 kyr date of the Younger Dryas Boundary.

The hypothesis that terrestrial catastrophes may happen on timescales
~0.1 Myr, due to the Earth running through swarms of debris from
disintegrating large comets, is likewise not new (Clube & Napier,
1984). However the accumulation of observations has allowed us to
build an astronomical model, closely based on the contemporary
environment, which can plausibly yield the postulated YDB (Younger
Dryas Boundary) catastrophe.

The interception of ~10E15 gm of material during the course of
disintegration is shown here to have been a reasonably probable event,
capable of yielding destruction on a continental scale.

The object of this paper is not to claim that such an encounter took
place at 12,900 BP -- that is a matter for Earth scientists -- but to
show that a convincing astronomical scenario can be constructed which
seems to give a satisfactory match to the major geophysical features
of the Younger Dryas Boundary data.

If indeed the YDB event was an astronomical catastrophe, its
occurrence bears little relation to current impact hazard assessments
derived from NEO surveys."

It was indeed an astronomical catastrophe. And the nature of the event
bears no resemblance whatsoever to anything in any NEO hazard
assessments, or anything in current impact theory.

With Professor Napier's work specifically proposing in refereed
literature that the Taurid Progenitor was the Younger Dryas comet, he
changed the game completely. Because he didn't just give us a
convincing astronomical model of the event. We also have a pretty good
picture of the physical properties of the thing that did the
disastrous deed. And if you can describe a beast, you can predict its
footprints.

It is important to note here that the astronomical model of the
Taurids implies that most catastrophic impact events are probably the
result of a very large cluster of smaller fragments, and cometary
debris. And not a single, large bolide.

Mark Boslough's simulations predict the temps, pressures, flow
directions, and rotation speeds, of a single impact down-blast vortex.
And since we are working from postulate that the events of the YDB
were caused by the impact storms, of the debris streams, of the
fragmented Taurid progenitor.

The YD impact hypothesis as it stands, describes tens of thousands of
such airbursts in a little over an hour. And accompanied by clouds of
particles down to the size dust grains falling into the atmosphere at
something like 30 km/per second, as the Earth crossed through the
orbital path of the giant fragmented comet's debris stream.

Firestone, and friends proposed destructive forces equivalent to as
much as 10E9 megatons of TNT. And at temps hotter than the surface of
the sun. (a half pound of TNT will blow a hole in the ground you could
lose a small car in)

Professor Napier states,

"The interception of ~10E15 gm of material during the course of
disintegration is shown here to have been a reasonably probable event,
capable of yielding destruction on a continental scale."..."


Cochrane/Pueyrredon Lake, Lago Posades on SW of dark plateau
-47.299381 -71.980131 .151 km el


Lago Ghio
-47.304100 -71.533653 .376 km el


1 km crater, 3 ground views
-47.323359 -70.786983 .725 km low


Guadal Grande white low
-46.725080 -69.835423 .299 km el low


SW edge of NE rim of black plateau
-45.844801 -69.674997 .506 km el


highest of 3 .2 km size round lakes on E edge of large dark melted
plateau
-45.710081 -69.435403 1.087 km el


white lake in 15 km wide basin
-45.595170 -69.536351 .674 km el low,
337 m under 1.011 km high SW past edge


-44.674044 -68.059731 .740 km el


-45.139829 -68.360533
1.36X.41 km size NNW,
.472 km el low at NNW bottom,
112 m below .482 km el plateau W of low point,
shows as usual no high rim,
confirming the formation by erosion
within a few seconds of
high density very hot directed blast
from air burst of ice comet fragment
arriving at perhaps 35 km/sec at low angle,
maybe 10-45 deg to ground --
common white minerals may arrive
from impactor.


-45.207627 -68.384444
2 km size crater on plateau,
with many fractal craters close together,
.378 km el low,
94 m below .452 km el plateau to NE,
with .2 km size crater on SE rim, .419 km low,
29 m below .448 km el plateau -- while
the very similar rim slope in angle and height,
that is the outer boundary of this long NS plateau,
is evidence that a much vaster plateau surface was
ablated away by the barrage of air burst comet fragments,
not by previous or subsequent massive water floods.

The plateau surface in general must have been partially melted and
levelled during the geoablative process.


Four fine ground photos on Google Earth N of this location show some
of the flat dark and red layers in this region:
Los Altares, Chubut Argentina, ground view,
-44.725178 -68.611603 .322 km el


Laguna de Agnia with many concave arc ridges uphill E
-43.807717 -69.690869 .603 km el low
~5X2 km pond size within 12 km basin,
impact features may extend E for 52 km.

white pond, fairly in line E of Laguna de Agria, Chubut
-43.903411 -69.200781 .471 km el
~.8X.2 km long pond, within 6 km wide basin --
the length of the whole feature is 52 km.


one crater within a fractal horde,
-42.960219 -68.310961 .977 km el low, 3 km size


Impact melt formation by low-altitude airburst processes, evidence from
small terrestrial craters and numerical modeling, H E Newsom & MBE
Boslough
2008 Mar 2p abstract: Rich Murray 2010.11.17
http://rmforall.blogspot.com/2010_11_01_archive.htm
Wednesday, November 17, 2010
[ at end of each long page, click on Older Posts ]
http://groups.yahoo.com/group/astrodeep/message/73
[ you may have to Copy and Paste URLs into your browser ]


3 times more downward energy from directed force of meteor airburst in
3D
simulations by Mark B. E. Boslough, Sandia Lab 2007.12.17: Rich Murray
2010.08.30
http://rmforall.blogspot.com/2010_08_01_archive.htm
Monday, August 30, 2010
[ at end of each long page, click on Older Posts ]
http://groups.yahoo.com/group/astrodeep/message/63
[you may have to Copy and Paste URLs into your browser]

[Extract]

http://74.125.155.132/scholar?q=cache:YY6MFUns_CkJ:scholar.google.com/+%22Mark+B\
oslough%22,+impacts&hl=en&as_sdt=10000000000
[ Extracts ]

"Dr. Boslough has also shown that an LAA [ Low Altitude Airburst ]
from a ~100 meter diameter NEO
melted sand into glass across a region about 10 km in diameter during
Libyan
Desert Glass impact ~35 million years ago.
During this event the LAA's fireball settled onto parts of Egypt and
Libya
for about a minute with temperatures approaching 5,000 K.
Its hypersonic blast wave extended radially for about 100 kilometers."


ground views of over 100 .1-.5 km shallow (ice comet fragment bursts)
craters, Bajada del Diablo, Argentina (.78-.13 Ma BP) [42.87 S 67.47 W]
Rogelio D Acevedo et al, Geomorphology 2009 Sept: Rich Murray 2010.03.28
http://rmforall.blogspot.com/2010_03_01_archive.htm
Saturday, March 27, 2010
http://groups.yahoo.com/group/astrodeep/message/47
______________________________________________


Rich Murray, MA
Boston University Graduate School 1967 psychology,
BS MIT 1964, history and physics,
1943 Otowi Road, Santa Fe, New Mexico 87505
505-819-7388 rmforall at gmail.com

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