Research team claims to have found evidence Lake Cheko is impact crater for Tunguska Event

May 21, 2012 by Bob Yirka report
Image: Geochemistry, Geophysics, Geosystems

(Phys.org) -- Early on the morning of June 30th, 1908, a huge explosion occurred in a remote part of Siberia near the Podkamennaya Tunguska River. So great was the blast that trees were knocked down in neat rows for nearly a thousand square miles and the sky lit up from parts of Asia to Great Britain. What caused that explosion has never been firmly settled. Most researchers agree that it was the result of either a comet or meteoroid, with most leaning towards the former due to the lack of both an impact crater and meteoroid fragments. Now however, a research team from Italy says that they have found proof that it was in fact a meteorite that struck the Earth and that a nearby lake is the impact crater. They have published the results of their findings in Geochemistry, Geophysics, Geosystems.

For years, amateurs and professionals alike have debated the cause of the Tunguska Event, as it’s come to be known as. Some suggest it was the work of extraterrestrials while others say it was god’s way of getting our attention. Serious scientists, on the other hand, have suggested its most likely cause was a comet melting and then vaporizing as it hit, leaving no real evidence behind. Unfortunately, that theory doesn’t hold up very well in light of the fact that scientists have found differences in the levels of carbon, nitrogen and isotopes of hydrogen and iridium, from the surrounding area which are similar in some respects to those found with certain asteroids. Also, tiny particles that sort of resemble meteorite components have been found in the wood of the fallen trees. None of this evidence can rule anything out however as it could mean there was a that had some rocks in it or a meteorite that vaporized due to a soft composition.

The Italian teams says it was a and claim they have proof of their assertion in the form of an as yet uncovered piece of something tangible beneath the sediment at the bottom of Lake Cheko; a shallow funnel shaped lake approximately five miles from where most believe was ground zero for the .

The team came to this conclusion after performing seismic measurements on the lake bottom in 1999 which showed that sentiment had been building for just about a hundred years, which would of course put it close to the and also gave evidence of something dense near the middle of the lake.

Further evidence came to light they say in 2009 when they returned to the lake and performed a magnetic survey, which they say showed an anomaly in the same location as their seismic measurements had detected. Now, after three more years of studying evidence they collected from the site, they’ve concluded that Lake Cheko is indeed an and that the dense object beneath the lakebed is the smoking gun.

Others of course aren’t so sure, and likely will remain pessimistic until someone digs up the object and studies it, proving it to be nothing more than a regular rock, or an object from space that left an impact crater as it struck over a century ago, finally solving the mystery.

Explore further: NASA sees massive Marie close enough to affect southern California coast

More information: Magnetic and seismic reflection study of Lake Cheko, a possible impact crater for the 1908 Tunguska Event, Geochemistry, Geophysics, Geosystems, VOL. 13, Q05008, 12 PP., 2012. doi:10.1029/2012GC004054

Abstract
A major explosion occurred on 30 June 1908 in the Tunguska region of Siberia, causing the destruction of over 2,000 km2 of taiga; pressure and seismic waves detected as far as 1,000 km away; bright luminescence in the night skies of Northern Europe and Central Asia; and other unusual phenomena. This “Tunguska Event” is probably related to the impact with the Earth of a cosmic body that exploded about 5–10 km above ground, releasing in the atmosphere 10–15 Mton of energy. Fragments of the impacting body have never been found, and its nature (comet or asteroid) is still a matter of debate. We report here results from a magnetic and seismic reflection study of a small (∼500 m diameter) lake, Lake Cheko, located about 8 km NW of the inferred explosion epicenter, that was proposed to be an impact crater left by a fragment of the Tunguska Cosmic Body. Seismic reflection and magnetic data revealed a P wave velocity/magnetic anomaly close to the lake center, about 10 m below the lake floor; this anomaly is compatible with the presence of a buried stony object and supports the impact crater origin for Lake Cheko.

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User comments : 20

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Jitterbewegung
1.7 / 5 (3) May 21, 2012
" in 1999 which showed that sentiment had been building for just about a hundred years,"

My sentiments exactly.
Squirrel
3 / 5 (4) May 21, 2012
For a picture of Lake Cheko
http://www.geotim...ter.html
gwrede
1 / 5 (1) May 21, 2012
There's a river going through the lake. I wouldn't be hard to compare river sediment from both sides of the lake.
julianpenrod
1 / 5 (10) May 21, 2012
Yet another example that, if an issue is left unaddressed for years among at least a certain crowd, new, illegitimate statements can be made and that crowd will accept them without question.
The earliest examinations of the Tunguska area revealed trees at the vey center of the blasted trees standing straight up! The comparison was to buildings at Ground Zero in Hiroshima, directly underneath the aerial detonation of the atomic bomb, still standing, while buildingsa around it were blown down. The conclusion was that Tunguska was an aerial explosion, not a ground impact!
daqman
5 / 5 (4) May 21, 2012
"located about 8 km NW of the inferred explosion epicenter"

If you take a look at the lake it is elongated and the long axis points due South East towards the explosion epicenter. That's exactly what you'd expect. It would be interesting to use Google Earth or something similar to look for similar features pointing to the same epicenter.
daqman
5 / 5 (11) May 21, 2012
The earliest examinations of the Tunguska area revealed trees at the vey center of the blasted trees standing straight up! The comparison was to buildings at Ground Zero in Hiroshima, directly underneath the aerial detonation of the atomic bomb, still standing, while buildingsa around it were blown down. The conclusion was that Tunguska was an aerial explosion, not a ground impact!


I've no idea what the first part of your comment was about. It made no sense at all.

As far as the aerial explosion is concerned that is still consistent with this finding. An object could explode in the air and a fragment of it continue on in one piece to form the indent that holds this lake.

Vendicar_Decarian
4.2 / 5 (5) May 21, 2012
Vendicar_Decarian
4 / 5 (4) May 21, 2012
Russkiycremepuff
1.5 / 5 (6) May 21, 2012
Very good pictures, Vendicar, but the second one does not appear to be the same lake as first picture, as it does not seem to have the gradients on all sides for /- sloping downward terrain that is typical of oblique crater walls. At home on excursion, I have only seen the Tunguska trees that lay flattened, but not the Lake Cheko. Some had said that it may have been UFO that crashed in lake and air pressure knocked down the trees. I did not know who to believe then.
I think it is best to wait until the lake bottom is excavated fully to see what is down there. From 1908, it is still not so old. If it were UFO, I do not think we will be told and it would remain government secret.
Hev
5 / 5 (3) May 21, 2012
According to the locals, who were there at the time, this was the result of feuds between rival tribes and their shamans. In the early morning of 30th June 1908, a flock of Agdy (thunder birds, big, black, made of iron with fiery eyes) were called by the shaman Magankan. The Agdy came down on the territory of the Shanyagir clan. Tents were blown into the air. People were hurt. 250 reindeer from the herd of Andrei Onkoul disappeared without trace - and other reindeer and also dogs were killed. The wooden storage houses on platforms, where they kept all their food, clothes and equipment were totaly destroyed in just a few seconds. The taiga forest was flattened for about 10,000 square kilometres in the areas of the rivers Chambe, Zhilushmo, and Kushmo. There was a great noise like thunder and great cracks in the earth. People fled leaving all their possessions. Two people died in the blast.
Russkiycremepuff
1.5 / 5 (6) May 21, 2012
(laughing) I have never heard that story before. I did not know anyone had ever lived in that area before 1908.
I found the pictures that VendicarDecarian presented. They are apparently the same lake, so it may be the perspective of pictures that make them appear to be two different lakes. Next to the second picture, I found this picture of strange animal that is possibly new species; but in the comments, there were some who said that it looks like Photoshopped picture. What is most disturbing is that it is hairless even if the face was Photoshopped. In Siberia, no animal can be hairless and survive, even in summer time.

http://emtoast.com/?p=1551
Caliban
5 / 5 (1) May 21, 2012
Yes, it would be nice to know on what dates these two photos were taken. The second appears to have been taken from a position approximately 180 degrees away from that at which the first was taken. it is also quite possible that the basin has continued to fill over time, and, assuming that the second photo is more recent, then the basin has filled considerably, thus drowning the steeply sloped sides visible in the first photo.

And is that some type of ridge-like formation(possible ejecta tail?) to the left in the first photo? Or is it some seasonal color variation in the area between the(visible at the right in second photo) two drainage inlets --or, possibly, both?

It would be very interesting, indeed, to see a topological map of the area.

Vendicar_Decarian
5 / 5 (4) May 21, 2012
It is a snapshot of Rush Limbaugh.

"I found this picture of strange animal that is possibly new species" - Russki
Vendicar_Decarian
5 / 5 (2) May 21, 2012
The first image is from the BBC. It doesn't look much like the second image of the lake.

However the terrain is roughly similar.

The BBC pic looks like it is synthetic and derived from data obtained when the lake contained much less water.

Google Earth provides a good view of the lake.
MorituriMax
3.7 / 5 (3) May 21, 2012
...and then the aliens said, "Shit! Cornfields are easier!"
Russkiycremepuff
1 / 5 (2) May 22, 2012
What aliens? There are aliens?
yaridanjo
1.7 / 5 (3) May 23, 2012
Earth is frequently impacted by comets or large meteorites.
Google: Vulcan Revealed

There have been at least 36 weather changing impact events over the last 15 thousand years. Normally, astronomers would scoff at this assertion. But there is a casual agent driving these frequent impacts. A half Jupiter mass brown dwarf in a fairly elliptical 4969 year orbit that draws Kuiper belt objects into (sometimes Earth threatening) 3:2 resonate orbits. The ones that threaten the inner planets of the solar system often fragment rounding the Sun forming swarms of relatively hard to detect meteorites (their volatile materials have been 'cooked off').
Gabor2000
5 / 5 (1) May 23, 2012
The idea that Lake Cheko is an impact crater was put forward as long ago as 2007 (see: Gasperini, L., et al. A possible impact crater for the 1908 Tunguska Event. Terra Nova, 2007, Vol. 19, 245251). But there is an article, in which this question is discussed in detail and the authors' answer is definite no: G. S. Collins et al. Evidence that Lake Cheko is not an impact crater, Terra Nova, 2008, Vol. 20, 165-168. Also, I must add that the problem of the Tunguska explosion is rather complicated. For more information about it I would recommend the following books: The Tungus Event or The Great Siberian Meteorite, by John Engledew (Algora Publishing), The Tunguska Mystery, by Vladimir Rubtsov (Springer) and, with some reservations, The Mystery of the Tunguska Fireball, by Surendra Verma (Totem Books). The question of the impactor's nature seems to be far from its final solution.
Sonhouse
not rated yet May 28, 2012
How big is that lake? Anyone know how deep and if anyone has done a dive there?

When you look at known meteorite strikes like the Barringer Crater in Arizona http://www.barrin...acts.php

I think that is a whole lot larger than the lake and the piece that hit in Arizona was thought to be less than 50 feet across. So it would seem that lake was made by just a tiny fraction of the mass of the Barringer crater, which implies that was just a tiny fragment of the entire mass of the original object.
Tallgrass Girl
2.4 / 5 (5) May 28, 2012
Yes, divers found large quantities of sunflower seed shells, indicating without a doubt that former FBI special agent Fox Mulder has already been here. Speculation is leaning toward belief that he had taken any truly relevant materials and is keeping them in an undisclosed location.