[meteorite-list] Asteroid impact effects

From: stan . <laser_maniac_at_meteoritecentral.com>
Date: Thu Apr 22 10:31:29 2004
Message-ID: <Law10-F101ToEkWQIhz000148dd_at_hotmail.com>

>Ahh, but here's where you're mistaken. Many of the most important
>variables determining the long-term effects of an impact are unknown
>and unknowable.

I guess we have a misunderstanding here then, because I was referring to the
predictability of prompt effects of such an impact, ie initial damage zones,
not long term climatic effects


>You have to know not only the initial quantity of material ejected
>into the troposphere, but the distribution of particle sizes produced,
>their reflectivities, their endurance, and their interaction with upper
>atmospheric global circulation patterns. Further complicating the
>picture are the effects of fires (soot) and gasses (H2O, CO2, CO, NO2,
>SO2, etc.) introduced into the atmosphere. The shutdown in
>photosynthesis will also change the O2-CO2 balance, altering the
>greenhouse effect.

ah, but we DO have models for all these sorts of data. obvious issues like
radioactivity asside, it matters little if wildfires are started via a
nuclear explosion or a comet impact, the atmoshperic longevity of particle
size 'x' should be the same for a nuke explosion as it is for an imact
event, ect.


>Global weather is a chaotic system, and thus even if you have
>perfectly quantified all the imaginable variables, the long term
>behavior of the overall system is nevertheless unpredictable.
>Even the tiniest change in one variable can completely alter the
>outcome.

the proverbial butterfly flapping it's wings causing a hurricane in the gulf
of mexico? I dont think thats so much of an issue here. the problem with
weather forcasting is that it's mainly about predicting the events of a
local environment that feels the effect of innumerable outside influences.
If you asked a meteoroligist to predict the local temperture of every day in
the month for january of next year for your home town, i wouldnt gamble on
his odds of being correct. However if you asked the same meteorologist to
predict the average global temperture for the month of january, I bet ya he
would be able to come pretty damn close to an accurate figure. Thats what we
are talking about here. The long term effects we care about here are not the
level of percitation in piorea on the 17th of march, 78 days after a 200
trillion ton impact event, we care if there is going to be any light out on
a global basis, or if the planet is going to be 90 degrees colder than it
normally is during the same time of the year, ect...

I agree that we really dont know enough to make highly accurate long term
predictions of the outcome of such an event, 'order of magnitude'
predictions shold be much more reliable i would think.

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Received on Sat 28 Feb 2004 09:04:06 PM PST