A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Astronomy Misc
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Mass Extinctions -- A Threat from Outer Space or Our Own Planet'sDetox? (Forwarded)



 
 
Thread Tools Display Modes
  #1  
Old March 9th 06, 04:28 PM posted to sci.astro
external usenet poster
 
Posts: n/a
Default Mass Extinctions -- A Threat from Outer Space or Our Own Planet'sDetox? (Forwarded)

Press and Publications Office
University of Leicester
Leicester, U.K.

09/03/2006

Mass Extinctions -- A Threat from Outer Space or Our Own Planet's Detox?

University scientists suggest extraterrestrial theories are flawed and
that more down to earth factors could have accounted for past mass
extinctions

Earth history has been punctuated by several mass extinctions rapidly
wiping out nearly all life forms on our planet. What causes these
catastrophic events? Are they really due to meteorite impacts? Current
research suggests that the cause may come from within our own planet --
the eruption of vast amounts of lava that brings a cocktail of gases
from deep inside the Earth and vents them into the atmosphere.

University of Leicester geologists, Professor Andy Saunders and Dr Marc
Reichow, are taking a fresh look at what may actually have wiped out the
dinosaurs 65 million years ago and caused other similarly cataclysmic
events, aware they may end up exploding a few popular myths.

The idea that meteorite impacts caused mass extinctions has been in
vogue over the last 25 years, since Louis Alverez's research team in
Berkeley, California published their work about an extraterrestrial
iridium anomaly found in 65-million-year-old layers at the
Cretaceous-Tertiary boundary. This anomaly only could be explained by an
extraterrestrial source, a large meteorite, hitting the Earth and
ultimately wiping the dinosaurs -- and many other organisms -- off the
Earth's surface.

Professor Saunders commented: "Impacts are suitably apocalyptic. They
are the stuff of Hollywood. It seems that every kid's dinosaur book ends
with a bang. But are they the real killers and are they solely
responsible for every mass extinction on earth? There is scant evidence
of impacts at the time of other major extinctions e.g., at the end of
the Permian, 250 million years ago, and at the end of the Triassic, 200
million years ago. The evidence that has been found does not seem large
enough to have triggered an extinction at these times."

Flood basalt eruptions are -- he says -- an alternative kill mechanism.
These do correspond with all main mass extinctions, within error of the
techniques used to determine the age of the volcanism. Furthermore, they
may have released enough greenhouse gases (SO2 and CO2) to dramatically
change the climate. The largest flood basalts on Earth (Siberian Traps
and Deccan Traps) coincide with the largest extinctions (end-Permian,
and end-Cretaceous). "Pure coincidence?", ask Saunders and Reichow.

While this is unlikely to be pure chance, the Leicester researchers are
interested in precisely what the kill mechanism may be. One possibility
is that the gases released by volcanic activity lead to a prolonged
volcanic winter induced by sulphur-rich aerosols, followed by a period
of CO2-induced warming.

Professor Andy Saunders and Dr. Marc Reichow at Leicester, in
collaboration with Anthony Cohen, Steve Self, and Mike Widdowson at the
Open University, have recently been awarded a NERC (Natural Environment
Research Council) grant to study the Siberian Traps and their
environmental impact.

The Siberian Traps are the largest known continental flood basalt
province. Erupted about 250 million years ago at high latitude in the
northern hemisphere, they are one of many known flood basalts provinces
-- vast outpourings of lava that covered large areas of the Earth's
surface. A major debate is underway concerning the origin of these
provinces -- including the Siberian Traps -- and their environmental impact.

Using radiometric dating techniques, they hope to constrain the age and,
combined with geochemical analysis, the extent, of the Siberian Traps.
Measuring how much gas was released during these eruptions 250 million
years ago is a considerable challenge. The researchers will study
microscopic inclusions trapped in minerals of the Siberian Traps rocks
to estimate the original gas contents. Using these data they hope to be
able to assess the amount of SO2 and CO2 released into the atmosphere
250 million years ago, and whether or not this caused climatic havoc,
wiping out nearly all life on earth. By studying the composition of
sedimentary rocks laid down at the time of the mass extinction, they
also hope to detect changes to seawater chemistry that resulted from
major changes in climate.

From these data Professor Saunders and his team hope to link the
volcanism to the extinction event. He explained: "If we can show, for
example, that the full extent of the Siberian Traps was erupted at the
same time, we can be confident that their environmental effects were
powerful. Understanding the actual kill mechanism is the next stage ...
watch this space."

More information is available from the website:
http://www.le.ac.uk/gl/ads/SiberianTraps/Index.html

Note to editors:

Further information is available from Professor Andy Saunders,
Department of Geology, University of Leicester, tel 0116 252 3923; or
from Dr Marc Reichow, email: mkr6 @ le.ac.uk .
  #2  
Old March 9th 06, 07:10 PM posted to sci.astro
external usenet poster
 
Posts: n/a
Default Mass Extinctions -- A Threat from Outer Space or Our Own Planet'sDetox? (Forwarded)

On a sunny day (Thu, 09 Mar 2006 11:28:02 -0500) it happened Andrew Yee
wrote in
:

Press and Publications Office
University of Leicester
Leicester, U.K.

09/03/2006

Mass Extinctions -- A Threat from Outer Space or Our Own Planet's Detox?

University scientists suggest extraterrestrial theories are flawed and
that more down to earth factors could have accounted for past mass
extinctions

Earth history has been punctuated by several mass extinctions rapidly


wiping out nearly all life forms on our planet. What causes these
catastrophic events? Are they really due to meteorite impacts? Current
research suggests that the cause may come from within our own planet --


Lookahere, we all know about Bush.


Flood basalt eruptions are -- he says -- an alternative kill mechanism.
These do correspond with all main mass extinctions, within error of the
techniques used to determine the age of the volcanism.


So maybe they were caused by the impacts?
  #3  
Old March 9th 06, 10:33 PM posted to sci.astro
external usenet poster
 
Posts: n/a
Default Mass Extinctions -- A Threat from Outer Space or Our Own Planet's Detox? (Forwarded)


"Jan Panteltje" wrote in message
...
On a sunny day (Thu, 09 Mar 2006 11:28:02 -0500) it happened Andrew Yee
wrote in
:

Press and Publications Office
University of Leicester
Leicester, U.K.

09/03/2006

Mass Extinctions -- A Threat from Outer Space or Our Own Planet's Detox?

University scientists suggest extraterrestrial theories are flawed and
that more down to earth factors could have accounted for past mass
extinctions

Earth history has been punctuated by several mass extinctions rapidly


wiping out nearly all life forms on our planet. What causes these
catastrophic events? Are they really due to meteorite impacts? Current
research suggests that the cause may come from within our own planet --


Lookahere, we all know about Bush.


That's just great. Perhaps you could inform us as to how many freckles he
has on his arse.

Flood basalt eruptions are -- he says -- an alternative kill mechanism.
These do correspond with all main mass extinctions, within error of the
techniques used to determine the age of the volcanism.


So maybe they were caused by the impacts?


Do you have any evidence that this was the case, or are you just
speculating?

George


  #4  
Old March 9th 06, 10:46 PM posted to sci.astro
external usenet poster
 
Posts: n/a
Default Mass Extinctions -- A Threat from Outer Space or Our Own Planet's Detox? (Forwarded)

On a sunny day (Thu, 09 Mar 2006 22:33:19 GMT) it happened "George"
wrote in P22Qf.14735$oL.12549@attbi_s71:


"Jan Panteltje" wrote in message
...
On a sunny day (Thu, 09 Mar 2006 11:28:02 -0500) it happened Andrew Yee
wrote in
:

Press and Publications Office
University of Leicester
Leicester, U.K.

09/03/2006

Mass Extinctions -- A Threat from Outer Space or Our Own Planet's Detox?

University scientists suggest extraterrestrial theories are flawed and
that more down to earth factors could have accounted for past mass
extinctions

Earth history has been punctuated by several mass extinctions rapidly


wiping out nearly all life forms on our planet. What causes these
catastrophic events? Are they really due to meteorite impacts? Current
research suggests that the cause may come from within our own planet --


Lookahere, we all know about Bush.


That's just great. Perhaps you could inform us as to how many freckles he
has on his arse.


Go to hell asshole, Bush is directly responsable for 5000 civilion death
in Iraq, 1000 dead US soldiers, helped to plot the twin towers with the Arabs he is in bed
with now to take over your ports, he is an Arab mole, and soon you will have to show your
rear end 3 times a day to heaven.




Flood basalt eruptions are -- he says -- an alternative kill mechanism.
These do correspond with all main mass extinctions, within error of the
techniques used to determine the age of the volcanism.


So maybe they were caused by the impacts?


Do you have any evidence that this was the case, or are you just
speculating?


Brain defect? These things happened at the same moment.
One would expect lava to flow when a huge ball of several km diameter entered through the crust.
Imagine it entering your head, oh, well, maybe it has that much empty space available, but the
earth has not.
Archimedes remember?
  #5  
Old March 10th 06, 02:49 AM posted to sci.astro
external usenet poster
 
Posts: n/a
Default Mass Extinctions -- A Threat from Outer Space or Our Own Planet's Detox? (Forwarded)


"Jan Panteltje" wrote in message
...
On a sunny day (Thu, 09 Mar 2006 22:33:19 GMT) it happened "George"
wrote in P22Qf.14735$oL.12549@attbi_s71:


"Jan Panteltje" wrote in message
...
On a sunny day (Thu, 09 Mar 2006 11:28:02 -0500) it happened Andrew Yee
wrote in
:

Press and Publications Office
University of Leicester
Leicester, U.K.

09/03/2006

Mass Extinctions -- A Threat from Outer Space or Our Own Planet's
Detox?

University scientists suggest extraterrestrial theories are flawed and
that more down to earth factors could have accounted for past mass
extinctions

Earth history has been punctuated by several mass extinctions rapidly

wiping out nearly all life forms on our planet. What causes these
catastrophic events? Are they really due to meteorite impacts? Current
research suggests that the cause may come from within our own planet --

Lookahere, we all know about Bush.


That's just great. Perhaps you could inform us as to how many freckles
he
has on his arse.


Go to hell asshole, Bush is directly responsable for 5000 civilion death
in Iraq, 1000 dead US soldiers, helped to plot the twin towers with the
Arabs he is in bed
with now to take over your ports, he is an Arab mole, and soon you will
have to show your
rear end 3 times a day to heaven.


Oh. Ok. So tell me, Jan. When you sit in your padded cell knitting those
imaginary sweaters, do you do so with a ****-eating grin on your face, or
are you just passing gas?

Flood basalt eruptions are -- he says -- an alternative kill mechanism.
These do correspond with all main mass extinctions, within error of the
techniques used to determine the age of the volcanism.

So maybe they were caused by the impacts?


Do you have any evidence that this was the case, or are you just
speculating?


Brain defect? These things happened at the same moment.


Umm, I'll repeat my question, since you saw fit to ignore it. Do you have
evidence that this was the case, or are you just speculating?

One would expect lava to flow when a huge ball of several km diameter
entered through the crust.


Since there have been dozens of impacts in Earth's geologic history, none
of which produced substantial amounts of lava, what other evidence do you
have?

George


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Unofficial Space Shuttle Launch Guide Steven S. Pietrobon Space Shuttle 0 October 3rd 05 05:36 AM
JimO writings on shuttle disaster, recovery Jim Oberg Space Shuttle 0 July 11th 05 06:32 PM
European high technology for the International Space Station Jacques van Oene Space Station 0 May 10th 04 02:40 PM
Clueless pundits (was High-flight rate Medium vs. New Heavy lift launchers) Rand Simberg Space Science Misc 18 February 14th 04 03:28 AM
International Space Station Science - One of NASA's rising stars Jacques van Oene Space Station 0 December 27th 03 01:32 PM


All times are GMT +1. The time now is 05:06 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 SpaceBanter.com.
The comments are property of their posters.