Re: Planet X: TUNGUSKA as Example

>>> Evidence, please.  Where is the seismological data?
>
> Insufficient.

The site I referred you to contains most available data on the event.

Observational data is all your going to get from an event that 
happened 100 years ago. You asked for evidence, you got it.

BTW there is insufficient physical evidence of a meteor or
 meteor crater to support the asteroid theory.


> Large pockets of methane gas do not form in the atmosphere,

1) Note: Potentially hazardous pockets of methane gas do form in 
   the atmosphere. The gas usually collects in confined spaces.

a) http://volcanoes.usgs.gov/Products/Pglossary/methane.html
   Methane explosion
   Sudden explosions of methane gas occur frequently near the 
   edges of active lava flows. Methane gas is generated when
   vegetation is covered and heated by molten lava. The explosive
   gas travels beneath the ground through cracks and fills abandoned 
   lava tubes for long distances around the margins of the flow. 
   Methane gas explosions have occurred at least 100 m from the 
   leading edge of a flow, blasting rocks and debris in all 
   directions...Illustration showing methane gas explosion 
   occurring above an old empty lava tube. Cracks, fractures, and 
   tubes in older flows beneath an active lava flow (red) serve 
   to an explosion.

b) Methane gas migration can be a potential problem at many of 
   Missouri's older landfills. Landfills constructed under more
   recent permit requirements must include a system for collection 
   and ventilation of gases. "DNR has inspected nearby buildings 
   for gas accumulations," said Jim Hull, director of DNR's Solid 
   Waste Management Program. "So far, no evidence of gas has been 
   found, but alarms have been installed in those buildings." Gas
   migration is not a problem for motorists passing a landfill. 
   Methane gas is not a contaminant for groundwater or surface
   water and is only dangerous when it collects to explosive
   levels in a building or basement.

   http://www.epa.state.il.us/environmental-progress/v24/n2/methane-gas.html
   Methane Gas Buildups Force Residents From Homes

   Methane gas blamed for duplex explosion after pilot ignited


2) Large pockets of Methane ( usually methane hydrates ) are known to occur
   both under the ocean and in pockets under land.

   http://marine.usgs.gov/fact-sheets/gas-hydrates/title.html
   Gas hydrates occur abundantly in nature, both in Arctic
   regions and in marine sediments. Gas hydrate is a crystalline 
   solid consisting of gas molecules, usually methane, each 
   surrounded by a cage of water molecules. It looks very much 
   like water ice. Methane hydrate is stable in ocean floor sediments 
   at water depths greater than 300 meters, and where it occurs, it
   is known to cement loose sediments in a surface layer several 
   hundred meters thick....
   A pair of relatively small areas, each about the size of the 
   State of Rhode Island, shows intense concentrations of gas hydrates.
   USGS scientists estimate that these areas contain more than 1,300
   trillion cubic feet of methane gas, an amount representing more 
   than 70 times the 1989 gas consumption of the United States....
   Methane bound in hydrates amounts to approximately 3,000 times 
   the volume of methane in the atmosphere. There is insufficient 
   information to judge what geological processes might most affect
   the stability of hydrates in sediments and the possible release 
   of methane into the atmosphere. Methane released as a result of 
   landslides caused by a sea-level fall would warm the Earth, as 
   would methane released from gas hydrates in Arctic sediments as
   they become warmed during a sea-level rise.


> but the pattern indicates an atmospheric blast, not a ground blast.

2.2 THE FOREST FALL
    The Tunguska spacebody explosion stimulation undertaken by
    Victor Korobeinikov, corresponding member of the Russian Academy 
    of Sciences, with co-workers at the Academy's Computer Center
    has shown the internal energy of the spacebody to be commensurate 
    with its kinetic energy to produce the existent forest fall [6].
    In plain language, this means that the Tunguska meteorite had to 
    be an enormous block of super-explosive! Moreover, it's possible 
    to demonstrate that the explosion of the hypothetical Tunguska 
    body must be practically completely due to its internal energy! It's 
    because the shape of the treefall reveals the presence of a  
    significant spherical component of the air-shock wave. But due 
    to the law of a conservation of a momentum, the explosion due to 
    a kinetic energy don't produce a spherical air-shock wave (a total 
    momentum of a spherical air-shock wave is zero, while the total
    momentum of the bolide's generated air-shock waves is qual to the
    momentum of the disintegrating meteorite). The absence of the 
    spherical component is clearly seen on Fig.4 of work [7]. In there 
    the air-shock wave of the "Tunguska meteorite" ( the latter is at 3
    km/s speed, i.e. practically already transferred all his momentum 
    to air-shock waves) is as must be - the conical one, which can't 
    produce the shape of the Tunguska forest fall!

    Recently published detailed calculations of the hypothesized 
    "Tunguska space body" completely confirm the idea about the conical
    shock wave. Thus in [MATEMATICHESKOE MODELIROVANIE, 1999, v.11, 
    No.10, p.49 (in Russ.) ] an attempt was made to model disintegration 
    of a comet with diameter 60 meters, speed 20 km/s, inclination of 
    a trajectory 45 degrees (imitating Tunguska). In the article initial 
    height of the comet disintergation was evaluated as 21 km (in my 
    opinion too low). They model the situation, as if the comet evaporates 
    in this point at once. Then they calculated how the debris (gas)
    cloud moves farther to the ground.
    Their results are very remarkable. First, they got (as I stated 
    for a long time) that the air-shock wave produced by the moving 
    cloud is conical one, but not a spherical one.
    But their another result is possibly even more important. They 
    got the following data of the air-shock wave just before reaching 
    the ground (at 1.7 km height): speed 3.5 km/s; typical transverse 
    dimension - 2 km, pressure - 40 bars. And behind the air-shock 
    wave there is the debris cloud. nfortunately, no data is given on 
    the cloud's details, but a little bit higher, at height 5 km it 
    has speed 10-11 km/s, density 2.5 kg/(m^3); temperature: 
    7000-8000 K. And such giant plasma column is to hit the ground
    (a forest) at great speed!...
    Here I just want to attract attention that in reality many groups 
    of trees survived in epicenter, and moreover even some single 
    standing in open places trees have no signs of burns!...
    The researcher of the Tunguska forest fall V. Fast writes [8] 
    that the shape of the air-shock wave front has been reconstructed 
    from the field of mean directions of the tree-fall. In order to 
    get a closed front, he had to use a field of directions forming an 
    angle of about 87.5 degrees with the mean directions of the 
    tree-fall, but not orthogonal to it. So the field of the mean
    directions of the tree-fall is vortex one.

    In other words, the fallen trees near the epicenter were rotated 
    from their radial (from the epicenter) position several degrees 
    clockwise in average. But how the meteorite explosion could produce
    such vortex air-shock wave? Such air-shock wave must transfer a 
    large torque. The evaluation by the author estimate it in order
    of 100-1000 billions of Newton*kilometre! The meteorite explosion 
    couldn't produce it.

    Another puzzle for the meteorite interpretation is the area of
    the forest fall on the ridge Chuvar (23 km, 279), which according 
    to the local Evenks have formed the same morning as the general 
    (Kulikovskii) one. It was discovered by the 1959 expedition. 
    Its square is 30-40 sq. km. and the trees damage was found to occur
    in about 1908. The peculiarity of that forest fall is that trees 
    were uprooted with their tops to the east (i.e. in the opposite of 
    what expected from the meteorite fall direction). So the supporters 
    of the meteorite fall prefer not to discuss it, or at least, talk
    just about accidental coincidence.

JD) No argument the blast occured above the ground (in the atmosphere)

> Furthermore, I'd like to see a seismometer output, not an "observer
> report".

1) There were not a lot of seismic stations in 1908 especially in Siberia,
   so don't expect to find a "seismometer output". Although I understand
   Irkursk (sp) had one.
2) Those that propose an asteroid or comet strike are also basing their
   theory on " observer reports".

> Observers can see all sorts of things, like UFOs, and "diffuse
> objects" near Orion.

And observers look through telescopes and conjecture all the answers to our
universes mysteries.

Observational data is not relevant ??? Hmmm.

JD