The oldest ice of North America resisted crossed warming
By Denis Delbecq • September 28th, 2008 in 23:06 · Category: Actuality
This ice has to see odd animals. Canadian researchers indeed discovered, under a layer of volcanic ash, of the ice from which the age would go back up in 740 000 years, according to two independent datings. They itemised their discovery in the magazine Science, on September 19th of this year. A sign that the pergélisol, the soil which remains frozen all year long, could resist the warming of climate in the past.
It is of the most ancient ice known in North America. The age could be got by dating volcanic ashes which recuperate the training of discovered ice some metres under the surface of the soil, in the region of Yukon which includes number pockets of frozen soil, in a discontinuous way. This ice, which attains several dozens metre in thickness, is not very cold today (around-2°C) but could resist in several interglacial periods, among which those who, around-120 000 years and-400 000 years, knew a climatic warming more important than today.
In Science, the researchers explain that «pergélisols and reservoirs of carbon linked which is in more than some metres under the surface of the soil could be much more stable than it was thought.» Until now, the scientists thought that in Yukon, all pergélisol had melted 120 000 years ago!
And it is nothing, since the cast iron of the pergélisol — who represent 20 % surfaces of the appeared lands liberates the carbon in form of gas with greenhouse effect, mainly of some methane. A gas which, although it remains less for a long time in the atmosphere a lot that the carbon dioxide, picks up twenty times more solar energy than it, causing fears to some researchers of a fad of climatic warming.
If the deep pergélisols is stable, it means that they could resist climatic warming in the course of next decades. A factor which it will be necessary to introduce into the models of simulation to make them more definite. But that they are not too quickly delighted, because the pergélisols of surface already has them begin melting. Liberating some carbon and causing the collapse of buildings (see for example pictures listed by Google).
Picture: © Charles Q Choi - Science
Article read 2,692 times. Tags:Canada, greenhouse effect, cast iron, pergelisol, climatic rechauffement
Comments in 
therefore the pergelisols presentent of catastrophic danger on the securites of the living etre or in matiere of sliding of fields or in matiere of liberation of carbon dioxide
-120 000 and-400 000, considered how being more important, at the moment! but also that the cast iron of pergelisols represents a factor that can accentuate the climatic warming which we suffer today, it is possible to tell themselves that changes to come would be possible be the most important that the earth is known since the appearance of the man on earth.