[meteorite-list] Impact Events' Kinetic Energy May Be Key to Understanding the Severity of Mass Extinctions

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:50:23 2004
Message-ID: <200204041625.IAA04334_at_zagami.jpl.nasa.gov>

http://www.geosociety.org/news/pr/02-19.htm

Geological Society of America
Boulder, Colorado

Contact:
Ann Cairns
Director – Communications and Marketing
acairns_at_geosociety.org, 303-357-1056

FOR IMMEDIATE RELEASE: April 3, 2002

GSA Release No. 02-19

Impact Events' Kinetic Energy May Be Key to Understanding the Severity
of Mass Extinctions

By Kara LeBeau, GSA Staff Writer

The kinetic energy created by asteroid and comet impacts with the Earth
may be key to linking some impacts with mass extinction events. Michael
Lucas, a geology student at Florida Gulf Coast University, believes that
the severity of four extinction events during the Mesozoic and Cenozoic
can be correlated with the total kinetic energy released by impacts that
occur during the geologic age of the mass extinction.

Lucas will present his findings April 4 at the Geological Society of
America's North-Central Section and Southeastern Section Joint Meeting
in Lexington, Kentucky.

Lucas analyzed the kinetic energy released by 31 of the largest impact
structures from the last 248 million years and correlated them with the
Norian, Tithonian, Late Eocene, and K-T extinction events. The impact
energy released during the geologic ages of each extinction event is
at least 10 million megatons of TNT equivalent yield per geologic age.
Lucas believes that this could represent a minimum impact energy
required to cause a global-scale mass extinction. His research results
also reveal that synchronous multiple impact events could also have
caused extinctions.

"Approximately ten percent of the impact structures on Earth are
doublets or twin structures, suggesting a nearly simultaneous impact
of binary asteroids or fragmented comets," he said. An example of a
twin impact structure would be the Kara / Ust-Kara twin impact
structure in Russia which is about 73 million years old.

CONTACT INFORMATION:

Michael P. Lucas
College of Arts & Sciences
Florida Gulf Coast University
10501 FGCU Blvd. South
Ft. Myers FL 33965 USA
E-mail: mlucas_at_fgcu.edu
Phone: (941) 590-7225
Abstract available at:
     http://gsa.confex.com/gsa/2002NC/finalprogram/abstract_32110.htm

Geological Society of America
Southeastern Section and North-Central Section Joint Meeting
April 3-5, 2002
Hyatt Regency Hotel and Lexington Civic Center
Lexington, KY

For information and assistance during the meeting, please see the media
assistant at the GSA registration table or call 859-253-1234.
Received on Thu 04 Apr 2002 11:25:28 AM PST