Beam me to Planet Gore !
Posted on 06/21/2008 4:40:14 PM PDT by Diana in Wisconsin
Watch out for the oceans.
That's the lesson of an extensive study by University of Wisconsin-Madison assistant professor Shanan Peters published June 15 in the journal Nature.
Peters looked at data gathered by scientists over many years and analyzed what they found at about 600 locations all over the continental United States and Alaska, going back more than 500 million years.
Changes in ocean environments related to sea level exert a driving influence on rates of extinction, which animals and plants survive or vanish, and the composition of life in the ocean, he found.
"This breakthrough speaks loudly to the future impending modern (oceanic) shelf destruction due to climate change on earth," said National Science Foundation program manager Rich Lane.
No matter what the cause of the ebb and flow of the oceans in various eras, the repeated and resultant extinctions must be considered, Lane said.
Scientists say there may have been as many as 23 mass extinction events over the last 3.5 billion years on earth, many involving simple forms of life such as single-celled microorganisms.
Over the past 540 million years, there have been five well-documented mass extinctions, primarily of maritime plants and animals, with as many as 75-95 percent of species lost.
For the most part, scientists have been unable to pin down the causes of the dramatic events, though in the case of the demise of the dinosaurs, they suspect that a large asteroid crashed into the planet.
"Impacts, for the most part, aren't associated with most extinctions," Peters said in an interview. "There have also been studies of volcanism, and some eruptions correspond to extinction, but many do not."
So the assistant professor of geology and geophysics looked at sea levels by reviewing previous studies of the geological record, which show a clear difference in composition of the earth when it is covered by the sea and when it is not.
He measured two types of marine shelf environments, one where sediments were derived from land erosion and the other composed primarily of calcium carbonate, which is produced in place by shelled organisms and chemical processes.
In the course of hundreds of millions of years the world's oceans have expanded and contracted in response to movement of the Earth's crust and changes in climate. There were periods when vast areas of continents, including Wisconsin, were flooded by shallow seas.
"Most of the major extinctions have come when sea levels were high," Peters explained.
"Anything we can learn about how the physical environment and life has changed in the past will tell us what to expect in the future."
The sea level has changed dramatically in the past, with each ice age, for instance, and 14,000 years ago there was ice over Madison, he said.
So in respect to climate change, he said, sea level will change whether the climate is warming or cooling.
"The bottom line is that the biosphere is well primed for the type of sea level change we are likely to see as a result of global warming," Peters said.
"The biggest thing we should worry about is the impact of sea level rise on humans. The scariest part is sea level rise from a human perspective in my opinion, because so many people live close to the sea. The toll will be large."
"...scientists have been unable to pin down the causes of the dramatic events..."
So they just chalk it up to Global Warming, LOL!
Let’s go with a rotating Presidency, R in the winter D in the summer:)
I hate it when the deadline to apply for government grants rolls around.
Geez! These greenies are hallucinating!
So, when the Ocean rises to a certain height, everyone will walk into the sea like lemmings....
I think he assumes that Mayor Nagin is president and cannot evacuate anyone fast enough to beat the 1 inch per year rise.
...according to all of these people, shouldn’t we all be dead by now?
No, it all boils down to “Vote Democrat or die”!
Gee, everyone is going to die. Duh.
The r’s have been thwarting their attempts to consolidate the inner cities for decades. The savior Obama is coming to rescue them.
So, did they uncover some SUV’s in any archaeological digs which might have contributed to ‘global climate change?’
Well let’s see. There was that Noah’s Ark thing, and that Atlantis thing, and there you have it!
Naw, School Bus Mayor Nagin does not have that Bagobama Rajneesh quality. The only thing he will evacuate to is that next rock of cocaine.
maybe there’s a wave of these. ;’)
Ebb and flow of the sea drives world’s big extinction events
University of Wisconsin-Madison | Jun 15, 2008 | Unknown
Posted on 06/15/2008 12:06:45 PM PDT by decimon
http://www.freerepublic.com/focus/f-chat/2031500/posts
 |
||
| · join · view topics · view or post blog · bookmark · post new topic · | ||
|
|
|||
Gods |
Just adding to the catalog, not sending a general distribution. |
||
|
· Mirabilis · Texas AM Anthropology News · Yahoo Anthro & Archaeo · · History or Science & Nature Podcasts · Excerpt, or Link only? · cgk's list of ping lists · |
|||
An incoming asteroid, you must destroy. An incoming missile, you must not destroy. There! Got it?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.