Environmental Effects

[PlutonianEmpire]

I'm looking for a good online calculator that'll help me determine the effect on the climate certain asteroid strikes will have. I know there's the "impact effect" web page by the University of Arizona, but I'm looking more towards calculators that show how the collision may affect the rest of the world as well and such.

[Captain Nephilim]

I seriously doubt anyone has created such a calculator, or posted it online. Any such calculations that have been done were probably done on a case-by-hypothetical-case basis by the particular author.

Some main factors that would determine the atmospheric effects of an impact:

- Relative velocity of impactor - An asteroid moving along a similar orbit as Earth, in roughly the same direction, would be less energetic than one which crossed Earth's orbit at a 90?° angle, or worse, one that hit the planet head on.

- Size/Mass/Density of impactor - Is it big and heavy, small and heavy, or big and light?

- Composition of impactor - There are three main types of asteroid: silicates (rock & metal), carbonaceous (carbon compounds), and nickel-iron. This is probably less important than the velocity and mass, since the vast majority of stuff kicked up into the atmosphere belongs to Earth already.

- Where it impacts - Deep ocean, shallow seas of continental shelves, or dry continental crust. Again, most of the junk blasted into the atmosphere is going to be of Earth origin, so this can really affect the outcome. Does it hit granite, sedimentary sandstone, shale? How much water is going to be flash-boiled?

- Wild-cards - Any number of other unforseen variables could affect the climate in such an impact. Some theorize that the one which hit the Mexican Yucatan peninsula and killed the dinosaurs splashed molten searing rock all over North America, setting massive forest fires that might have burned for weeks, dumping megatons of carbon into the air and removing a biological sink from the planet. Whether that would make the situation worse, or just add insult to injury though, might be hard to say.

If you're looking for some educated people who might know something about a calculator for this, I'd email someone here: http://www.llnl.gov/planetary/

It's the web page for the Proceedings of the Planetary Defense Workshop, at Lawrence Livermore in 1995.

(Oh, and you might see if your local library has Rain of Fire and Ice, by John S. Lewis, for a very enlightening treatment of this subject)

[buggs_moran]

No calculators per se, but this table gives a generalized idea of what can happen...

http://www4.tpg.com.au/users/horsts/climate.htm

The authors of the University of Arizona calculator knew that the calculations regarding environmental impact were too variable and time consuming...

From pg 17: To make reasonable estimates of the severity of these effects requires detailed, time-consuming computations involving a large suite of model parameters (for example, target chemistry and mass-velocity distributions for the ejected material; Toon et al. 1997). Such calculations are well beyond the scope of our simple program; we direct readers interested in these processes to the above references for further information

Another link that describes after effects...
http://neo.jpl.nasa.gov/news/news096.html

[PlutonianEmpire]

thanks.

I got interested in this when I had a dream where an asteroid slammed into the minnesota-canada border (i live in Minnesota), coming in from the south at a 30 degree angle (90 degrees being vertical). I also began wondering what would happen after a 350 meter wide asteroid slams into the planet just south of minneapolis (i currently live 44 miles/71 kilometers north-northwest of minneapolis), also coming in from the south, but at a 45 degree angle.

And yes, I already used the impact effects calculator from the University of Arizona to determine the main impact. It's pretty informative.

[buggs_moran]

Boy you have detailed dreams.... However, I hear it's cold up there, lots of dreaming to do. While you're at it, check out the Manson Impact Structure, only a few hundred miles from you... Nothing to see, but very interesting, and we are very overdue for another...

http://www.igsb.uiowa.edu/Browse/manson99/mansonNew.htm

[PlutonianEmpire]

Boy you have detailed dreams.... However, I hear it's cold up there, lots of dreaming to do. While you're at it, check out the Manson Impact Structure, only a few hundred miles from you... Nothing to see, but very interesting, and we are very overdue for another...

http://www.igsb.uiowa.edu/Browse/manson99/mansonNew.htm

Thanks Just so you know, the minnesota-canada border meteorite was the one in my dream, the minneapolis impact was not--I came up with that idea while awake, and before I had the dream, i think.