When the glaciers return

Discussion in 'Earth Science' started by sculptor, Aug 9, 2017.

  1. sculptor Valued Senior Member

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    When the glaciers return: Will the driftless area remain driftless?
    Are there driftless areas in Eurasia?
     
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  3. spidergoat Valued Senior Member

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    You mean continental drift?
     
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  5. sculptor Valued Senior Member

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    NO

    The driftless area is an area in nw illinois, nw iowa, sw minnisota, and (mostly within) sw wisconsin.
    For at least 1 million years or 4 heavy glacial cycles the glaciers came north of the area, east of the area, west of the area, and hooked south of the area without coming into the driftless area. "Driftless has to do with glacial drift and deposits.

    There does not seem to be much evidence for heavy glaciation in the surrounding area before 1 million years ago, and there is none found within the driftless area.
    here's a map showing the locations of the glaciers for 4 recent glacial periods

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    altogether an interesting phenomenon.
     
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  7. sculptor Valued Senior Member

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    Hmm
    Nobody finds the driftless area interesting?
    Climatology, geology, and a darned interesting landscape ain't enough?

    Oh, well
     
  8. sideshowbob Sorry, wrong number. Valued Senior Member

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    The Illuminati have their headquarters just outside Madison.
     
  9. dumbest man on earth Real Eyes Realize Real Lies Valued Senior Member

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    Hmm...
    Could this "driftless area" have anything to do with the Great Lakes?
    Possibly a Saltwater Ocean/Sea may have existed that may have somehow impeded/impacted Glaciation?
    And possibly due to the further Glacial Periods and any ensuing Plate Tectonics may even have impacted the formation/location of the Great Lakes?
    Just Hmming...
     
  10. sculptor Valued Senior Member

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    I think not. ) That being said: "To do with" opens doors, one of which I have queried below)

    Yes indeed: Plate Tectonics have impacted the formation/location of the Great Lakes.
    The great lakes are on an ancient rift zone which is still active causing 5+ earthquakes/year. Where they are located was where land masses collided and accreted then rifted apart then collided then rifted, etc...
    the whole great lakes area is much a basin which filled with glaciers during the times of glaciation, and is currently rising due to isostatic rebound.

    The driftless area is part of the south west wisconsin uplands, and was not covered by glaciers, so no isostatic rebound(at least not in the last million years).

    The two seem dissimilar enough to rule out causal linkages?

    I would surmise that being part(the southern part) of the uplands is much more a causal factor for the area being non glaciated/drifted.

    I find the topography and history of the area fascinating.(If you're ever in the area, a drive down the back roads may fascinate you as much as it does me.)

    Why are the uplands uplands?

    If a great weight is piled on one side of a plate, would that be sufficient to tilt the plate and raise another part of the plate?
     
    Last edited: Aug 11, 2017
  11. DaveC426913 Valued Senior Member

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    The Great Lakes were created by a glaciation event. So glaciation must have occurred pre-GL.
     
  12. sculptor Valued Senior Member

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    That was common belief before the fault under lake superior was studied.

    Alternately: The thinner and unstable crust of the greatlakes region lent it's self to being heavily glaciated?

    Perhaps, once an area has been scoured by glaciers, it may be easier for future glaciers to follow extant paths?
     
  13. DaveC426913 Valued Senior Member

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    Yah. It seems I bin skooled by Wiki.
     
  14. spidergoat Valued Senior Member

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    The glaciers are never coming back.
     
  15. dumbest man on earth Real Eyes Realize Real Lies Valued Senior Member

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    Grok'd...
     
  16. dumbest man on earth Real Eyes Realize Real Lies Valued Senior Member

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    Grok'd...
     
  17. sculptor Valued Senior Member

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    And, you know this for a certainty?
    How?
     
  18. origin Trump is the best argument against a democracy. Valued Senior Member

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    I suppose the unglaciated area is due to the highlands in Wisconsin diverting the glacier front.
     
  19. Write4U Valued Senior Member

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    I find it interesting, but what does it look like today? When you start counting in hundreds of thousands or millions of years, there is no telling what has caused these phenomena. They cannot be used as a graph.
    a single large comet may change the earths climate for millennia, but would have nothing to do with a cyclic phenomenon. Perhaps it does. Perhaps we have a planet in a solar orbit so large that it only comes near the earth every say 500,000 and throws our climate complete out of whack, or something like that.

    But I am interested in the trend over the past say 1000 years, which can be researched and approximated from recorded history of world wide events and more importantly the effects of human industry in the past 250 years.
     
    Last edited: Aug 12, 2017
  20. origin Trump is the best argument against a democracy. Valued Senior Member

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    I think you completely missed the point.
    The question was why was the small area in Wisconsin near the Mississippi River unglaciated during the last 4 glacial advances.
     
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  21. spidergoat Valued Senior Member

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    We altered the trajectory of the future. This path is now unreachable.
     
  22. sculptor Valued Senior Member

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    yes

    and
    another curiosity
    in the last million years, we've most likely had 8-9 glacial periods, why do we only find evidence for 4 in this area? did the Illinoisan glacial period erase some of the earlier periods?

    Growing up in the midwest near the illinois/wisconsin border east of the fox river, everything I saw was altered by the glaciers. So, seeing unaltered(by glaciers) landscape is darned different and interesting.
    In the driftless, you will find narrow valleys with flat bottoms and a small stream or meandering rivers surrounded by 150 ft bluffs/cliffs. The farming is constrained by the relative flatness of the ground. Mostly small farms in the valleys, and some atop the bluffs.
     
  23. sculptor Valued Senior Member

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    From what I've read, that would need over 750 ppm of co2................ which seems unobtainable.
    However, we also have the 400kyr hypothesis, and a serious lack of knowledge as to what leads to either a superinterglacial or an end to this ice age.
     

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