Tunguska Impact Crater Found?

BigBadBus writes in with a claim by an Italian team that they may have found an impact crater resulting from the 1908 Tunguska explosion over Siberia. The BBC story quotes a number of impact experts who doubt the Italians' claim. "A University of Bologna team says a lake near the epicenter of the blast may be occupying a crater hollowed out by a chunk of rock that hit the ground. Lake Cheko — though shallow — fits the proportions of a small, bowl-shaped impact crater, say the Italy-based scientists. Their investigation of the lake bottom's geology reveals a funnel-like shape not seen in neighboring lakes. In addition, a geophysics survey of the lake bed has turned up an unusual feature about 10m down which could either be compacted lake sediments or a buried fragment of space rock."

Comments

Re:University of Bologna?

[Kintar1900]

They're just letting you know in advance about the validity of their claims. ;)

In other news...

[Critical Facilities]

A University of Bologna team says a lake near the epicenter of the blast may be occupying a crater hollowed out by a chunk of rock that hit the ground.

An official with the University of Horseshit was quoted as saying "That's not a lake, that's partially liquified alien spaceships.". Reached for a response prior to teaching a class at the College of Bullcrap, Professor Dumbass had the following to say, "Well, it could be a meteor, it could be a meatball, who can say really?"

Not a troll

[drinkypoo]

It's not a troll. It's called humor. And it's entirely ontopic and appropriate as well - the article basically has a bunch of people saying "it might be some shit" but they have no proof whatsoever. They claim to have ruled out several other possibilities which led them to the "conclusion" (how do you come to a conclusion with no evidence?) that it was the Tunguska impact crater. Now let's see, how many problems are there with this?

1. Tunguska probably wouldn't even have a crater, because it was an airburst. At best, it would have several small ones, which might not even be detectable any more.
2. The article claims that if there were a crater, it would be shaped differently.
3. There is no supporting evidence that this was the Tunguska crater.

Now, if they dig into this lake and figure out what the submerged lump in it is, which might be a rock and might just be a lump of sediment, then this will be more interesting. But this is a completely non-story story. There are no facts here, other than that some people have made an assumption which might or might not be warranted, because they lacked imagination to come up with hypotheses they couldn't shoot down.

A better title would be "Scientists believe they have located Tunguska Crater without corroborating evidence".

Parent comment, even if intended to be a joke just about the name of the Uni (I do not believe it is, based on having RTFA, shock amazement) is still entirely apt. Perhaps the bonehead who modded it troll should check out the moderation guidelines?

Re:University of Bologna?

[NeoTerra]

I have a BS degree from the University of Bologna and...

Any conversation would stop there, right?

any idea how large the region is?

[iHasaFlavour]

Tunguska is big, really big..

And extremely remote. It's not even slightly surprising that this was missed.

The original expidition didn't head to the impact site until years after the event, and still they found a devastated surface, and no-one went back again for a very long time.

Until fairly recently it just wasn't feasable to do any kind of large scale study of the region. I think people sometimes forget just how barking huge our planet is, you'd be amazed at the number of area's that are still effectivelly blanks on the map, or mapped by air/satellite only.

Unfortunately

[porkchop_d_clown]

The most widely accepted explanation for not finding the crater is that there isn't one: Most geologists believe the Tunguska object exploded in the air. (This sounds crazy, but it's apparently possible - just as a person doing a belly flop off a cliff is going to be killed by the impact, a meteor can be destroyed by the impact with the lower atmosphere.)

http://en.wikipedia.org/wiki/Tunguska_event

Re:Impact, eh?

[PoliTech]

You may have been joking AC (Pun Intended), but the "Tesla Death Ray" has been suggested as one of the possible causes of the Tunguska event for many many years.

Here is an About.com article that talks about it more. http://paranormal.about.com/cs/earthmysteries/a/aa 021604.htm

The text below is lifted from this site: http://prometheus.al.ru/english/phisik/onichelson/ tunguska.htm

The Tunguska event took place on the morning of June 30th, 1908. An explosion estimated to be equivalent to 10-15 megatons of TNT flattened 500,000 acres of pine forest near the Stony Tunguska River in central Siberia. Whole herds of reindeer were destroyed. Several nomadic villages were reported to have vanished. The explosion was heard over a radius of 620 miles. When an expedition was made to the area in 1927 to find evidence of the meteorite presumed to have caused the blast, no impact crater was found. When the ground was drilled for pieces of nickel, iron, or stone, the main constituents of meteorites, none were found down to a depth of 118 feet.

Several explanations have been given for the Tunguska event. The officially accepted version is that a 100,000 ton fragment of Encke's Comet, composed mainly of dust and ice, entered the atmosphere at 62,000 mph, heated up, and exploded over the earth's surface creating a fireball and shock wave but no crater. Alternative explanations of the disaster include a renegade mini-black hole or an alien space ship crashing into the earth with the resulting release of energy.

Associating Tesla with the Tunguska event comes close to putting the inventor's power transmission idea in the same speculative category as ancient astronauts. However, historical facts point to the possibility that this event was caused by a test firing of Tesla's energy weapon.

In 1907 and 1908, Tesla wrote about the destructive effects of his energy transmitter. His Wardenclyffe facility was much larger than the Colorado Springs device that destroyed the power station's generator. Then, in 1915, he stated bluntly:

It is perfectly practical to transmit electrical energy without wires and produce destructive effects at a distance. I have already constructed a wireless transmitter which makes this possible. ... But when unavoidable [it] may be used to destroy property and life. The art is already so far developed that the great destructive effects can be produced at any point on the globe, defined beforehand with great accuracy (emphasis added).

He seems to confess to such a test having taken place before 1915, and, though the evidence is circumstantial, Tesla had the motive and the means to cause the Tunguska event. His transmitter could generate energy levels and frequencies capable of releasing the destructive force of 10 megatons, or more, of TNT. And the overlooked genius was desperate.

Tesla was just enough of a mad scientist to make what would otherwise sound kooky, at least somewhat plausible.

Re:Impact, eh?

[himi]

I call bullshit simply based on the question of where the hell Tesla would have gotten the ~80 petajoules of energy needed for a 20 megaton explosion, regardless of how wonderful his deathray may have been. Even if he was charging some massive bank of capacitors for a year, that would require 2.5GW for the whole year, which is utterly ridiculous for 1908.

himi