Notices
Results 1 to 18 of 18

Thread: Has there ever been the ice age?

  1. #1 Has there ever been the ice age? 
    Suspended
    Join Date
    Feb 2006
    Posts
    46
    This theory gained a footing only in the 1840s, when two researchers, Charpentier and Agassiz tried to explain the landscape forms of the Alps by using it and later it concerned the whole of Northern Europe. It is indeed surprising that this theory came to light almost at the same time as the thoughts of Darwin about the birth of animal species. Both these theories gained simultaneous attention in the society of the day.

    In any case it has been thought that there have been several ice ages on the earth. It has even been said that such tropical and hot areas as The Sahara, Africa, Saudi Arabia, Yemen, Australia, India, Madagascar and also South America (as has been presented for instance in the books "Jääkausi” (Ice age) / Björn Kurten and "Muuttuva maa" / Pentti Eskola) would have been covered with a large continental glacier, tens of millions years ago. The latest ice age is assumed to have started "just" about 500,000 years ago and come to an end 10,000 years ago. Then ice sheets were supposed to have covered at their widest point 55 million km2 and the thickness of the ice would have been at its best over 3 kilometres (about 3,3 yards).

    Why have we to think about the ice age? Have we any reason to believe in it? Perhaps those marks, which have been interpreted as those of an ice age, have been caused by something other than an ice age? We will now ponder the enigma of the ice age.

    http://koti.phnet.fi/petripaavola/Ha...e_ice_age.html


    Reply With Quote  
     

  2.  
     

  3. #2  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    Should you care to examine the southern and northern extremities of the planet you will observe that we are still in an ice age.


    Reply With Quote  
     

  4. #3  
    Forum Isotope Zelos's Avatar
    Join Date
    Jun 2006
    Posts
    2,755
    we are
    since when is 3km the same as 3,3 yards, i am not so good on imperial units, basacly cause i hate them, but aint 1 yard about 0,9somethingmore meters?

    the evidence of an ice age is simply to much to be ignored, thats the reason we "know" it have been.
    the same with evolution
    bigbang
    earth creation
    etc, when the evidence are to great to be ignored science "know" it have happened
    Reply With Quote  
     

  5. #4  
    Forum Cosmic Wizard SkinWalker's Avatar
    Join Date
    Apr 2005
    Location
    Grand Prairie, TX
    Posts
    2,377
    Obviously this is *not* a religious question and one for Earth Sciences. Topic moved.
    Reply With Quote  
     

  6. #5  
    Forum Junior Lucifer's Avatar
    Join Date
    Jan 2006
    Location
    Close to 290125001
    Posts
    223
    Ice is not motionless. Glaciers are not weightless. Ice builds glaciers and glaciers move. Glaciers on the move leave footprints. So when we find this footprints in places we don't see ice today, we know ice was there. From the extent of the damage, we know how much ice was needed to leave such a footprint.
    “If the misery of the poor be caused not by the laws of nature, but by our institutions, great is our sin.” -Charles Darwin
    Reply With Quote  
     

  7. #6  
    Forum Professor Pendragon's Avatar
    Join Date
    Jan 2005
    Location
    Nederland
    Posts
    1,085
    exactly, or the fact that regions which used to be covered by ice (like Skandinavia) have risen enormously once the weight of the ice had disappeared. Easy to prove with marine sediments at mountain summits.
    Reply With Quote  
     

  8. #7  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    Quote Originally Posted by Pendragon
    . Easy to prove with marine sediments at mountain summits.
    Ah, no. That was the Flood. :wink:
    Reply With Quote  
     

  9. #8  
    Forum Professor Pendragon's Avatar
    Join Date
    Jan 2005
    Location
    Nederland
    Posts
    1,085
    A flood elevating sea-level 3km, long enough for sediments to collect at mountain summits? Only god could do that :P
    Reply With Quote  
     

  10. #9  
    Forum Freshman
    Join Date
    Jun 2005
    Posts
    14
    Isn't the idea to adress the subject question?

    Yes the Ice Age was the last of perhaps 10 major glaciations each lasting on average about 50,000yr and separated by interglacial periods of 70,000yr. Toward the end of the Ice Age about 25,000yr ago, the ocean started freezing eventually causing ocean temperature to drop below that of the atmosphere/land. This caused the climate to change from cloudy to clear and the ice started to melt about 20,000yr ago. It is only because of the difficulty of adapting to these changes that forced and allowed man to evolve.

    Any questions? I will try to answer.
    Reply With Quote  
     

  11. #10  
    Forum Professor Pendragon's Avatar
    Join Date
    Jan 2005
    Location
    Nederland
    Posts
    1,085
    Quote Originally Posted by vgbell
    Isn't the idea to adress the subject question?
    The original poster clearly wants to see evidence of the Ice Age, so we discuss some landscape features which wouldnt be possible without one. In his opinion your description of the events is only a theory to be proven.

    Speaking of which, I haven't seen PetriFB back here after his post..
    Reply With Quote  
     

  12. #11  
    Forum Freshman
    Join Date
    Jun 2005
    Posts
    14
    It is not a theory. You can read it directly fron Antarctic ice core and ocean sediment data. I suppose the IA ending might be considered a theory but the evidence is in the sediment data if you can interpret it.
    Reply With Quote  
     

  13. #12  
    Forum Professor Pendragon's Avatar
    Join Date
    Jan 2005
    Location
    Nederland
    Posts
    1,085
    Quote Originally Posted by vgbell
    It is not a theory. You can read it directly fron Antarctic ice core and ocean sediment data. I suppose the IA ending might be considered a theory but the evidence is in the sediment data if you can interpret it.
    Good, then we agree with eachother :wink:
    Reply With Quote  
     

  14. #13  
    Forum Senior
    Join Date
    Sep 2006
    Posts
    399
    Glaciers also explain how so called "erratics", or large bits of rock which are completely out-of-situ managed to end up where they are today. Before it was found that ice could flow, the placement of these erratics baffled geologists and many obscure and whack theories were hypothesized to explain their existance.

    I suppose you could have glaciers without an ice-age, but what the heck, I thought I'd chuck that in because I'm sure you could (and someone's probably already done it) look at the occurence of erratics to prove the scale of the glaciation (generally, the nearer the equator the more extensive the glaciation), and thus deduce that there must have been an ice age.
    Reply With Quote  
     

  15. #14  
    Forum Freshman
    Join Date
    Sep 2006
    Posts
    16
    There is no one single piece of evidence that says "there are ice ages". It's more a collection of evidence that shows us through scientific logic that this MUST have happened. Evidence from geology as others have discussed here, as well as biological evidence that we see from the fossil record of extinct species of Ice Age animals, as well as Anthropological evidence.

    For example, we know that humans began to appear in the Northeastern United States around 13,000 years ago. This rather conveniently coincides with the timetable we know of for the receeding of the glaciers from this region. Before 13,000ya though, we know there were humans in North America. Therefore when this is added to the geological and biological proof, it fits perfectly. Humans could not live in the US NE becuase it was covered by glaciers. once those glaciers receeded, humans moved in. The archeological record supports this, and when pieced together, the geological and archaeological record fit flawlessly.

    Geological evidence from my area of New York are unavoidable as well. When the glaciers covered the NE, they pulled up and destroyed much of the rock and soil that was there. This is why you do not find Dinosaurs in New York State. When the glaciers came through they destroyed and pushed up all rock newer than Devonian era (in Western new York at least). This is why in this region we have amazing oucroppings and exposures of fossiliferous Devonian, Odrvician, and Silurian bedrock.
    Reply With Quote  
     

  16. #15  
    Cooking Something Good MacGyver1968's Avatar
    Join Date
    Aug 2006
    Location
    Dallas, Texas
    Posts
    2,051
    Is there a main theory on the causes of the ice age? I heard somewhere that the sun's output fluctuates, that during the ice age, the amount of sun spots was decreased, lowering the amount of solar energy that hit the earth...and in turn, lowering the temperature. Is this true?
    Fixin' shit that ain't broke.
    Reply With Quote  
     

  17. #16  
    Guest
    Another supporting piece of evidence is the 'petrified' tree remains and other 'land' artifacts found on the sea floor indicating those areas were above sea level at some time.
    Reply With Quote  
     

  18. #17  
    Forum Sophomore DarcgreY's Avatar
    Join Date
    Oct 2006
    Posts
    135
    I think I read somewhere that the recent iceage began when North and South America joined at the Ismuth of Panama cutting off currents between the Atlantic and Pacific that moderated the Earths' climate. That occured several million years ago.
    Reply With Quote  
     

  19. #18  
    Forum Sophomore
    Join Date
    Oct 2006
    Posts
    107
    Quote Originally Posted by MacGyver1968
    Is there a main theory on the causes of the ice age? I heard somewhere that the sun's output fluctuates, that during the ice age, the amount of sun spots was decreased, lowering the amount of solar energy that hit the earth...and in turn, lowering the temperature. Is this true?
    Solar Cycles are based on how many sunspots there are. Solar Cycles tend to be roughly 12 years long. Sunspots then would not have an impact on a multi-thousand-year process.

    However the sun might still have a hand in the process being that it is the sole source of heat to the Earth. Maybe there is a longer term sun cycle (other than simple ageing) or perhaps some sun cycles are different to others (already proved likley). Other possible influences would include earth atmospheric changes, perhaps aggrivated by volcanism, impacts, variations in dust levels, carbon dioxide levels, and so on.


    Edit: DarcgreY's idea certainly also has some merit.

    Incidently it does show that earth's climate is a bit of a delicate thing... Bring on the Climate change debate
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •