© Margie Turrin/Lamont-Doherty Earth Observatory
Icebergs discharged from Allison Glacier float near Kullorsuaq, western Greenland.
More than a million years ago, frosty
Greenland was ice-free, its bare bedrock exposed for 280,000 years, researchers have found.
During this exposed stint, the island's overall ice cover could have dropped by more than 90 percent, the scientists reported today (Dec. 7) in the journal
Nature.
Previous studies have reported that Greenland's ice shrank in the distant past, but this study is the first to explain how long a span Greenland may have endured without its usual frozen cover. This discovery hints that its surface ice was more variable than once thought — which does not bode well for its future stability in a warming world, the researchers said.
As valuable as moon rocks
The researchers gathered their data from isotopes — atoms of the same element but with a different number of neutrons — extracted from bedrock minerals. The isotopes, beryllium 10 and aluminum 26, are produced only by cosmic rays, which means that they only occur when the rock that holds them is exposed; as such they can offer clues about when rocks were bare of ice, and for how long.
Comment: This article on Live Science is a bit controversial as far as their view of Earth changes goes. It appears that the scientists who produced the data, along with the site itself, are quite blinded to simple questions this data raises because of their belief in man-made global warming.
The elephant in the room is obviously WHY a landmass at high latitude has over a very long period of time consistently frozen and then melted. After all, there was no mass burning of fossil fuels or dangerous levels of methane created by industrial animal farming.
There is data showing that the Earth simply goes through cyclical periods of warming and cooling. These periods are also interspersed with planetary cataclysms such as space object impacts and airbursts, unstable geological activity, disruptions in the Gulf Stream, natural disasters. Science's uniformitarian view of history and change cannot allow for such events though, because science is a symbol of man's control over nature and so those in the ivory towers of scientific and educational institutions hold the power of ancient priests.
To admit to the lack of control over cyclical catastrophes and the precariousness of life on Earth would rob the scientific establishment of its power over the people and rob the government of a placid and docile, easily controlled and subjugated public.
Comment: See also: