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GIA is the earth’s response to the removal of the great ice sheets

Glacial Isostatic Adjustment (GIA). GIA is the earth’s response to the removal of the great ice sheets. Last glacial maximum 18,000 yrs ago Since then, ice melted back. http://jesse.usra.edu/ archive/jesse01-300-01/. Why (Glacial Isostatic Adjustment) Motion Today?.

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GIA is the earth’s response to the removal of the great ice sheets

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  1. Glacial Isostatic Adjustment (GIA) GIA is the earth’s response to the removal of the great ice sheets Last glacial maximum 18,000 yrs ago Since then, ice melted back http://jesse.usra.edu/ archive/jesse01-300-01/

  2. Why (Glacial Isostatic Adjustment) Motion Today? Small motions resulting from “post-glacial rebound” (GPS can detect motions as small as 1 mm or 1/25 of an inch per year) stem from the fact that the mantle below the earth’s crust flows like a super-viscous fluid -- much, much stickier than road tar or maple syrup. The mantle is still flowing to fill areas underneath the places where the heavy ice sheets pushed out the mantle 18,000 years ago. MANTLE FLOWS OUT MANTLE FLOWS BACK

  3. Other Constraints on GIA in North America Raised beach Successive beaches left as fossil shorelines, recording uplift history Tide gauge at Churchill Tide gauge shows land rising today Within 1,500 km of Hudson Bay only 1 T. G.

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