[FPSPACE] The George Brown Jr ammendment

[Jens Kieffer-Olsen]

-----Original Message-----
From: E.P. Grondine [mailto:epgrondine at hotmail.com] 
Sent: Thursday, May 21, 2009 10:26 AM

> First off, I'd also like to mention to Jens the
> Rio Cuarto impacts. These appear to have killed
> nearly everyone living east of the Andes, while
> the deaths due to global climatic collapse still
> have to be worked out.

 I think not! The area destroyed in the impact was
 just 25 times larger than the Tunguska impact area
 according to Masse, Janecky, and Barrientos:
 
http://www.stanford.edu/dept/archaeology/cgi-bin/TAG/drupal/?q=content/cyber
-archaeology-0

 "Rio Cuarto was likely more than 1000 megatons and
 may have devastated an area greater than 50,000 km2
 in central Argentina."

 Hydrogen bombs detonated by Dwight D. Eisenhower and
 Nikita S. Khrushchev went close to 100 megatons. It
 was fear of nuclear fallout rather than of destructive
 power that stopped them from upping the ante beyond
 that. A non-radioactive detonation of 1000 megatons is
 very much a local rather than regional, let alone global,
 event.

 I hope you don't mention Rio Cuarto as an example of
 a strike from a comet? Wikipedia says:
 http://en.wikipedia.org/wiki/Rio_Cuarto_craters

 "Models of the Río Cuarto event suggest that the object
 struck at an angle of no more than 15 degrees from the
 horizontal [...] The object was thought to be a
 "carbonaceous chondritic" asteroid [...]"

 Comets generally strike at higher angles than 15°.

 Finally, Ed, you fail to mention the dispute initiated
 in 2002 by Phil Bland et al. on the origin of Rio Cuarto:
 http://www.skyandtelescope.com/news/3306051.html?page=1&c=y

 "[...] This would suggest that the Rio Cuarto craters
 are not craters at all but rather long hollows carved
 and shaped over thousands of years by prevailing winds."

 Maybe Iturralde in Bolivia is a better place to look for
 signs of recent megadeath caused by cometary impact?
 
--
Jens Kieffer-Olsen
Slagelse, Denmark