Arbitrarily, obvious math, estimated, little difference, safe to assume, I suspect, I think, etc. Thats enough please.
Bill Kieskowski > While I agree that my number of '1000 years' was picked arbitrarily, to be > realistic, if we can not prepair hardened food production facilities within > the warning time avalible, it would matter little if the 'nuclear winter' > lasted for 1000 years or only a few years, as both numbers are well over the > elngth of time a human can go without food, even your average overweight > american! :) > > Also, with regards to an impact that would cause long term effects in > comparison to prompt killoffs, keep in mind that the blast radius of an > explosion scales at the cube of the energy released, whereas the amount of > dust that gets kicked up into the air scales pretty linearly. So to point > out the obvious math, when you compare 2 impacts, one that causes a prompt > damage of radius 'x' to one that causes prompt damage of radius 2x, the > latter will eject 8 times as much material into the air. 3x you are at 27 > times as much material, and so on. (this rule of thumb applies to nuclear > weapons and other 'conventional' explosions, as impact events liberate > energy during their entire trip through the atmosphere, the numbers may be a > little diffrent, but I'd say they are close enough for the purpose at hand). > To put that in perspective, an impact event that liberates 1000 times as > much energy (and hence dust into the atmosphere) as krakatoa would only have > a damage radius of about 250 miles (defined as the point where buildings, > trees, ect are knocked over) and a thermal burn radius of about 1000 miles, > but I suspect that number is a bit off, as the curvature of the earth would > come into play by then. Obviously there are many places where such an impact > could occur without killing any signifigant number of people (in the global > sense) > > > I think that it's safe to assume there are a large number of areas on the > planet where an impact could occur that would cause orders of magnitude more > climate altering dust to go into the atmosphere, than say krakatoa, without > killing off a large portion of the life on this planet. > > > >On the subject of the aftermath of a large impact -- specifically the > >duration of > >"nuclear winter", Stan wrote: > > > > > "In the event of a large impact, we would need to build an enclosure > >that > > > protects food crops from the environment, and provides an alternate > >source > > > of energy to the crops. Rice isn't going to grow if the sun is blacked > >out > >for > > > 1000 years because of a comet induced nuclear winter." > > > >An impact that doesn't kill everyone and everything within hours should not > >have effects lasting anywhere near that long. Months to a few years, I > >would > >guess, depending on the size and velocity of the impactor. It's a very > >difficult > >thing to estimate since the only contemporary, large energy releasing > >events > >we have to compare to are many orders of magnitude smaller in energy. > >Krakatoa's four explosions on August 27, 1883, for instance, are estimated > >to have released the energy equivalent of around 200 megatons of TNT. They > >gave us red sunsets for more than a year and lowered global temperatures as > >much as 1.2 C. > > _________________________________________________________________ > Stay informed on Election 2004 and the race to Super Tuesday. > http://special.msn.com/msn/election2004.armx > > > ______________________________________________ > Meteorite-list mailing list > [EMAIL PROTECTED] > http://www.pairlist.net/mailman/listinfo/meteorite-list ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
