[meteorite-list] Tunguska Questions

From: Meteorites USA <eric_at_meteoritecentral.com>
Date: Fri, 15 May 2009 09:16:06 -0700
Message-ID: <4A0D9546.4010606_at_meteoritesusa.com>

Hi all,

In regard to Tunguska and bioturbation.

Paul H's post on bioturbation brings up an interesting question. The
first expedition led by Leonid Kulik to Tunguska in 1927 to study the
devastation and search for meteorites happened 19 years AFTER the event
in 1908, (He had an earlier expedition in 1921 but wasn't successful in
reaching the epicenter until 1927).

19 years is a LONG time for meteorites in the forested and swampy
environment full of little critters, insects, and plants that could bury
any stones. How deep can meteorites be buried in 19 years of snow, rain
storms, mudslides, spring melt, critters, ants, termites, and other animals?

Could bioturbation be one cause for the failed attempts to recover
meteorites at Tunguska?

You also have to take into account Leonid Kulik's mindset at the time.
He was thinking that meteorites would be directly beneath the blast at
the epicenter. Which made sense. Would he be looking for meteorites
10-40 miles away from the epicenter? He attributed the circular swampy
bogs to craters formed by the meteorite impacts, which unfortunately
turned out to be incorrect. Did he search for meteorites only under the
epicenter? How far from the epicenter did his search area expand?

Were there other expeditions to Tunguska to search in the 10-40 mile
ring from the epicenter?

Most scientists believe that the sheer force and energy of the blast at
Tunguska event vaporized every trace of the meteoroid explaining that
this is why there are no fragments to be recovered. This obviously makes
sense, but would EVERYTHING be vaporized?

Take a look at the "accepted" theory of Chixulub and the extinction of
the dinosaurs. This widely accepted theory is now being challenged.
Perhaps we should look at Tunguska again, in a new light.

I am just wondering something out loud here about the Tunguska event.
Yesterday I sent a load of links and questions and surprisingly got no
response. Come on, this is the largest meteorite related blast in recent
recorded history. So I'll will ask again.

Is it possible that there are in fact meteorites that survived the
Tunguska event by being blasted away much further from the epicenter
than previously thought?

Below is a copy of my post about some questions I had on Tunguska in
yesterday's post.

-----------------------ORIGINAL POST---------------------

Hi Listees,

Recently there's been more interest in the Tunguska event. More
scientists are trying to explain it, and some are even looking at a lake
near the blasts epicenter believing that this is the missing crater.
http://news.bbc.co.uk/2/hi/science/nature/6239334.stm

Photo of Lake Cheko:
http://a52.g.akamaitech.net/f/52/827/1d/www.space.com/images/070626_lake_cheko_02.jpg

A witness in Vanovara (36 Miles SE of the epicenter) said in O. Richard
Norton's "Rocks From Space"

"The crash was followed by noise like stones falling from the sky, or
guns firing."

and

"when I lay on the ground I covered my head because I was afraid that
stones might hit it."

We all know too well that witness reports aren't ideal information but
useful anyway. But, how would this person know to say that there was a
"noise like stones falling" unless that were the case? Or did the
witnesses report become tainted after countless interviews? How many
times was this witness interviewed?

I know people have searched for meteorites under and around the
epicenter area. But what if this was a stony meteoroid, and the
explosion blasted meteorite pieces 30-50 miles away. The devastation
this explosion caused is evidence that it was one hell of a blast and
was on par with a nuclear explosion.

YouTube Video: http://www.youtube.com/watch?v=EiXpp-i442s

Donald Yoemans (JPL) states in the History Channel video that this blast
was 15 megatons of equivalent energy "roughly 1000 times that of the
Hiroshima blast."

VERY COOL ARTIST RENDERING: http://svidea.us/misha/image/tunguska2.jpg

Photos of Devastation:
http://astro.wsu.edu/worthey/astro/html/im-meteor/tunguska-photo.jpg
http://upload.wikimedia.org/wikipedia/commons/a/ad/Tunguska.png
http://www.wilsonsalmanac.com/images1/tunguska3.jpg
http://www.world-mysteries.com/sci_tu3.gif
Artist Rendering: http://aura.gaia.com/photos/34/338910/large/tunguska-1.jpg
Area Map: http://www.world-mysteries.com/sci_tunguska1.gif
Blast Damage Area: http://www.world-mysteries.com/sci_tu2.gif

When you factor in all this information, how come people aren't looking
30-40 miles away for debris from this blast. If it was as powerful as
they say (as evidenced by the downed trees and other devastation)
wouldn't it make perfect sense that area around the blast would be
completely void of meteorites as is the case?

Having said that, wouldn't it be prudent to look further away from the
blasts epicenter for fragments? How far will a blast such as that throw
debris? If a Navy destroyer can launch a huge shell a hundred miles
using a few pounds of gunpowder, how far can a meteoroid blast such as
this launch stone fragments?

Bomb squad techs and investigators will be the first to tell you that
there's always something left over from a blast no matter how powerful.
Pieces get thrown sometimes miles from the epicenter of powerful blast.
In the case of Tunguska this blast was nuclear powerful! Yes a lot of
the mass would have been melted and disintegrated but, how likely is it
really that the blast would make ALL trace of the meteoroid disappear?

Could there be meteorite pieces within a 30-50 mile ring around the
epicenter?

-- 
Regards,
Eric Wichman
Meteorites USA
http://www.meteoritesusa.com
904-236-5394

Received on Fri 15 May 2009 12:16:06 PM PDT