dissident wrote:BTW, read the comments below the linked article. You see a bunch of amateurs using "proof by sound of plausibility" to claim the meteor triggered volcanism. These people should go and buy a clue. Any volcanism from the meteor would be in the region of its impact and not locate on the other side of the plant. Also, volcanism is a slow process and not some rapid instability which can be triggered off by a meteor impact. The Deccan traps did not need the meteor to form.
vox_mundi wrote:dissident wrote:BTW, read the comments below the linked article. You see a bunch of amateurs using "proof by sound of plausibility" to claim the meteor triggered volcanism. These people should go and buy a clue. Any volcanism from the meteor would be in the region of its impact and not locate on the other side of the plant. Also, volcanism is a slow process and not some rapid instability which can be triggered off by a meteor impact. The Deccan traps did not need the meteor to form.
I disagree ...
The physics of Antipodal Impact Shock Dynamics has been around for over 20 years.
A good primer ...
http://www.newgeology.us/presentation35.html
http://www.princeton.edu/main/news/arch ... /90/32S94/
for what it's worth, we also see this in forensic analysis of blows to the head. The brain will show an internal injury antipodal to the original blow
dissident wrote: India was plowing into Asia during that epoch giving rise to the Himalayas. That is the process responsible for the Deccan traps. Do some research first.
dohboi wrote:Why the Earth’s past has scientists so worried about sea level rise
By Chris Mooney
http://www.washingtonpost.com/news/ener ... evel-rise/
dissident wrote:dohboi wrote:Why the Earth’s past has scientists so worried about sea level rise
By Chris Mooney
http://www.washingtonpost.com/news/ener ... evel-rise/
So much waffle. The most obvious inference is that one gets 6 meters of sea level rise with relatively little warming. So looking at current sea level rise and thinking that "we are not committed" to six meters is total BS. We are committed for sure. The article also seems to think that global warming can be held at 1.5 C. That is must be some kind of joke. We are already guaranteed over 2 C with current CO2 levels.
In fact, the closest analogue is the mid-Pliocene with its 400 ppmv of CO2. And in this case 6 m is some lower bound and the actual sea levels were probably much much higher.
Alfred Tennyson wrote:We are not now that strength which in old days
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
Scientists at Stanford University are channeling their inner Superman by using X-ray vision to fight bad guys climate change. Their synchrotron, one of the most powerful X-ray machines in the world, can reveal chemicals deep within coral skeletons that illustrate what the weather was doing at different points in the animal’s long life. The new technique can show ocean temperatures and precipitation patterns from 500 years ago.
For comparison, detailed written weather records only go back about 150 years. That’s why paleoclimatologists (who study the climate of way back when) are taking clues from nature that’s been around for a while, like tree rings, volcanic ash, ice cores, and, now, coral. By reconstructing the climate of the past, they hope to prepare us for the one in our future.
“Climate is the thing that is constantly sending these species out through time without humans even being involved,” says Cooper. “That’s the bit that is really completely new.”
The team were surprised by another finding that emerged: it wasn’t the long cold periods that wiped out megafauna, as some have suggested – it was warming.
“What we found, which we were staggered by: no matter how we analysed the data, abrupt warmings drove the extinctions or the replacements,” says team member Chris Turney of the University of New South Wales in Sydney, Australia.
It is most likely that warming was such a killer because it arrives rapidly – temperatures change far more abruptly than they do at the onset of a cooling period, says Cooper.
Gifford Miller, a paleoclimatologist at the University of Colorado, called the paper "a coup de grace on the Medieval Warm Period." Miller said it shows "with great clarity of evidence" that "the idea of a consistently warm Medieval period is certainly an oversimplification and of little utility."
Astrid Ogilvie, a climate historian currently based at Iceland's Akureyri University, said the study "shows that the climate is clearly more complicated and variable than people earlier assumed." As for the Vikings, the climate story has been dimming for some time, she said. "I do not like the simplistic argument that the Greenland people went there when it was warm, and then 'it got cold and they died'," she said. "I think the Medieval Warm Period has been built on many false premises, but it still clings to the popular imagination."
Alfred Tennyson wrote:We are not now that strength which in old days
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
Tanada wrote:I don't know if I would classify the MWP as PALEO, but I can't think of a better thread to move it to either.
Paleoclimatology data are derived from natural sources such as tree rings, ice cores, corals, and ocean and lake sediments. These proxy climate data extend the archive of weather and climate information hundreds to millions of years. The data include geophysical or biological measurement time series and some reconstructed climate variables such as temperature and precipitation.
University of Bristol Cabot Institute researchers and their colleagues today published research that further documents the unprecedented rate of environmental change occurring today, compared to that which occurred during natural events in Earth's history.
The research, published online on 4 January in Nature Geosciences reconstructs the changes in atmospheric carbon dioxide (pCO2) during a global environmental change event that occurred about 120 Million years ago. New geochemical data provide evidence that pCO2 increased in response to volcanic outgassing and remained high for around 1.5-2 million years, until enhanced organic matter burial in an oxygen-poor ocean caused areturn to original levels.
Lead author Dr David Naafs explained: 'Past records of climate change must be well characterised if we want to understand how it affected or will affect ecosystems. It has been suggested that the event we studied is a suitable analogue to what is happening today due to human activity and that a rapid increase in pCO2 caused ocean acidification and a biological crisis amongst a group of calcifying marine algae. Our work confirms that there was a large increase in pCO2. The change, however, appears to have been far slower than that of today, taking place over hundreds of thousands of years, rather than the centuries over which human activity is increasing atmospheric carbon dioxide levels. So despite earlier claims, our research indicates that it is extremely unlikely that widespread surface ocean acidification occurred during this event.'
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