Posted on 11/01/2007 10:28:47 AM PDT by blam
Melting Glacier Reveals Ancient Tree Stumps
LiveScience.com
Tue Oct 30, 2:15 PM ET
Melting glaciers in Western Canada are revealing tree stumps up to 7,000 years old where the region's rivers of ice have retreated to a historic minimum, a geologist said today.
Johannes Koch of The College of Wooster in Ohio found the fresh-looking, intact tree stumps beside retreating glaciers in Garibaldi Provincial Park, about 40 miles (60 kilometers) north of Vancouver, British Columbia.
Radiocarbon dating of the wood from the stumps revealed the wood was far from freshsome of it dated back to within a few thousand years of the end of the last ice age.
"The stumps were in very good condition sometimes with bark preserved," said Koch, who conducted the work as part of his doctoral thesis at Simon Fraser University in Burnaby, British Columbia. Koch will present his results on Oct. 31 at the Geological Society of America annual meeting in Denver.
The pristine condition of the wood, he said, can best be explained by the stumps having spent all of the last seven millennia under tens to hundreds of meters of ice. All stumps were still rooted to their original soil and location.
"Thus they really indicate when the glaciers overrode them, and their kill date gives the age of the glacier advance," Koch said. The age of the newly revealed ancient trees also indicates how long the glaciers have covered this region.
The recently warming climate released the stumps from their icy tombs, Koch said.
Koch compared the kill dates of the trees in the southern and northern Coast Mountains of British Columbia and those in the mid- and southern Rocky Mountains in Canada to similar records from the Yukon Territory, the European Alps, New Zealand and South America. He also looked at the age of Oetzi, the prehistoric mummified alpine "Iceman" found at Niederjoch Glacier, and similarly well-preserved wood from glaciers and snowfields in Scandinavia.
The radiocarbon dates seem to be the same around the world, according to Koch. There have been many advances and retreats of these glaciers over the past 7,000 years, but no retreats that have pushed them back so far upstream as to expose these trees.
The age of the tree stumps gives new emphasis to the well-documented before-and-after photographs of retreating glaciers during the past 100 years.
"It seems like an unprecedented change in a short amount of time," Koch said. "From this work and many other studies looking at forcings of the climate system, one has to turn away from natural ones alone to explain this dramatic change of the past 150 years."
Oh the humanatree!
Another consideration is that the stumps could have been sheared/broken off at ground level.
Yes, but glacier ground level tends to be rather deeper than pre-glacier ground level - especially with 7,000 years of movement.
Unless...the guy is a pretty complete idiot and the stumps were churned around in the ice along with other stumps, and they are dating wood in the moraine and picking the oldest. It has happened before. I doubt it, but several things don't add up here.
Glaciers ride on the ground and scrap up rock/dirt with them and pile them up elsewhere. Their full weight would not allow them to ride over a stump.
I think this is really a ice sheet.
There are several screwy things in the report, but yeah, even if you accept that the MWP was regional (Europe, North America and Siberia being the "region"), it still doesn't follow.
Can you give me the source for this graph, please?
One of the problems is that these graphs do not reflect the current level of CO2 such as the following related graph does
http://www.clearlight.com/~mhieb/WVFossils/last_400k_yrs.html
or
http://en.wikipedia.org/wiki/Image:Carbon_Dioxide_400kyr-2.png
One of the things misleading about that graph is the starting point of about 200 PPM.
It makes the current level of C02 seem very high at 380 PPM or so.
Well, past history shows a peak of 300 PPM even on that graph.
So were freaking out over an 80 PPM more then past few hundred thousand years of history shows?
And there are professionals that question the accuracy of the ice core data as well to begin with.
Bottom line though. There are large natural cycles that we have absolutely no control over.
No, 7,000 years is well within the realm of biblical Creationists. We don’t know how long Adam was in the garden before he fell.
The first link I gave in my previous posting has this intriguing fact:
“For example, during the Ordovician Period 460 million years ago CO2 concentrations were 4400 ppm while temperatures then were about the same as they are today.”
That’s more than 10x today’s numbers and I suspect that since all we can measure today are averages over long periods of time, there were probably some quite significantly higher spikes over brief periods. So the CO2 concentration impacting temperature argument may not be the major driver of temperature.
After cutting down the trees they had to offer up dinosaurs for carbon offsets to the Algorasaurus co., hence the dinosaur bone pits.
Wow, talk about “old growth” lumber... :-)
It appears that this article has been purged from Yahoo News.
http://www.youtube.com/watch?v=iusq6j8cG1o#p3YNh4w1CEA
It seems to be a mystery to all the folks who made comments about it, but I'm sure there are more than a handful of folks here who will recognize what it is immediately.
How can we have 7,000 year old trees when the earth is only 6,000 years old?
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