[meteorite-list] Crater maker

[Chris Peterson]

When you talk about something as large as the K-T event, even defining 
"crater" gets a bit tough. The primary physical structure was probably 
around 150km in diameter. Given an impactor that was 10km in diameter, this 
doesn't fall far outside the 10:1 rule. At the other end of the range, you 
have Sikhote-Alin, producing marginal craters- certainly as small as craters 
on the Earth can be, and in many cases the bodies producing them are not 
identified. In the middle you have something like Barringer crater, where it 
would seem that the crater may be unusually large because the air blast was 
so large. It is all very complicated. All the same, given the wide range, if 
you have to pick a single figure I think the 10:1 rule still gives a good 
indication of what to expect.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message ----- 
From: "Michael L Blood" <mlblood at cox.net>
To: <cynapse at charter.net>; "Meteorite List" 
<Meteorite-list at meteoritecentral.com>
Sent: Sunday, March 20, 2005 7:28 PM
Subject: Re: [meteorite-list] Crater maker


> Thanks to all who responded.
>        Other than the 10 to 1 ratio, I pretty much thought
> the same as what most people stated.
>        Here is what I did respond with:
> --
> One "formula" in which I hold very little
> belief, is a ratio of 10 times the diameter of the
> impactor. This question has far to many variables, such
> as speed of meteorite upon contact, type of soil
> and composition of meteorite (ie, stone or Iron),
> angle of trajectory, etc. In addition, the K-T event
> produced a crater (as indicated by hypercompacted
> quartz) with a diameter of 500 miles - but the impactor
> is estimated at "only" 6 miles in diameter - the ol' 10
> to one ratio implies there should have "only" been a crater
> 60 miles in diameter.
>        Best wishes, Michael