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Under the ice.

  1. Aug 17, 2004 #1
    Last decade ice core digging in the West Antlantic Ice Sheet (WAIS) gave a big surprise. Diatoms in the mud under the ice sheet revealed that there has been a sea bottom with a maximum age of some 500,000 years but possibly younger.

    Science, Vol 281, Issue 5373, 82-85 , 3 July 1998

    There was big commotion but apart from scary stories about sudden collapses of ice sheets the attention receded. Yet we are facing a formal "not understood" (science talk for mystery) phenonemon.

    Guess what's under the Greenland ice sheet.

    Grass and Trees!

    More here.

    I hope that they can date the sample roughly as carbon dating only goes to about 45,000 years. I think it will be a next surpsrise I doubt that these samples are older than half a million year.

    Strange that millions of years is automatically assumed because of the "counter intuitive" estimate for younger years, although this would probably yield a world record. Mineralization (fossilization) of small objects can be done in weeks in the right circumstances. These samples seem not to be fossilized. (source It's the question if sub freezing temperatures stop the process completely for millions of years.

    It may be as young as the last interglacial, the Eemian, 130,000 years ago. Then it would be a nice smoking gun for my little pet idea.
  2. jcsd
  3. Sep 14, 2004 #2
    Greenland is covered by a cap of ice so deep, that perhaps will never melt. Norway while situated at the same latitude has a summer and rich vegetation. The gulf streem currents warms scandanavia and the rest of Europe.

    Professor Hans Petersen, while researching the depts of the Equatorial Atlantic, at depths of 3,219 meters, the Swiss Albatross, discovered fresh water plants.


    There are small marine animals, named forminiforos of two priniple generos, Globorotalia menardii and Globorotalia truncatulinoides. The first being caracterized by its shell that spirals in clockwise direction and inhabits warm waters, while the latter in clockwise direction and cold waters. The warm water type never appears above a line that extends from the Azores to the Canary Islands. While the cold water type dominates the cuadrilateral Northwest Atlantic. The middle Atlantic between Africa and South America, is abundantly populated with the warm type. Notwithstanding the cold type makes its aparition in the Equatorial Atlantic. and the warm type pentrates a barrior in direction east. Where is the barrier?
  4. Sep 15, 2004 #3
    Thanks for those links Rader,

    The behavior of isotopes of diatoms and planctonic and benthic foraminifera is intensely studied in the ODP-sediment cores indeed. But the results are often puzzling like this example. Ca/mg and Ca/Sr ratios are other attempts for interpretation as paleo thermometers. Right here we see the discussion about it.

    And why Greenland indeed? Why not the North West Territories. There as been a lot of ice in Canada (the Laurentide ice sheet) early in the last glaciation cycle. It started to melt before the onset of the Last Glacial Maximum (22,000 - 18,000) even before the LGM Eurasian (Weichselian) ice sheet reached its eastermost extent, the Kara sea N of Russia, stopping short of the Taimyr Peninsula.

    Nowadays, all that ice surrounding Greenland has melted. Why not the centre-most ice of Greenland itself? On the contrary, the ice sheet of Greenland really started to grow like crazy, after the ice age, the Holocene. Incidentely the Kilimanjaro glaciers also came into being after the ice age in the same period.

    It looks that the "ice age" was not so much about temperatures at all. I would say a global moistening event instead of a global warming event.
  5. Sep 17, 2004 #4
    Last edited: Sep 17, 2004
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