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CONTINENTAL ICE SHEET - GREENLAND PowerPoint Presentation
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CONTINENTAL ICE SHEET - GREENLAND

CONTINENTAL ICE SHEET - GREENLAND

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CONTINENTAL ICE SHEET - GREENLAND

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  1. CONTINENTAL ICE SHEET - GREENLAND

  2. ALPINE ICE- VALLEY GLACIER(S)

  3. GLACIER BAY, ALASKA

  4. ALL GLACIERS HAVE TWO ZONESACCUMULATION = + MASSABLATION = - MASS

  5. “Firn Line” = Equilibrium Line Dinwoody Glacier. Wind River Range, Wyoming. Italian alps

  6. GAME OF MASS BALANCESNOW IN vs WATER/ICE OUT

  7. IDEALIZED MOTION- CROSS SECTION

  8. GLEN’S FLOW LAW e= strain rateA = constant related to ice temperature t= basal shear stress (?)n = exponent with an average value of 3 rgh sin a

  9. TEMPERATURE MATTERS Does cold or warm ice strain more rapidly?

  10. STRESS-STRAIN RESPONSE (DEBRIS FLOW) (WATER)

  11. MASS FLUX - BIRD’S EYE VIEW

  12. VELOCITY DISTRIBUTION - BIRD’S EYE

  13. WHAT’S GOING ON AT THE BED???? VELOCITY IN SECTION VIEW

  14. WHAT IS THE TEMPERATURE AT THE BASE OF THE ICE?-GEOTHERMAL-FRICTION-AMBIENT AIR

  15. WARM BASED ICE sliding along bed

  16. FOX GLACIER, New Zealand

  17. COLD-BASED ICEfrozen to bed

  18. DRY VALLEY AREA-- ANTARTICA

  19. COMPARE, WARM VS COLD

  20. EROSION REQUIRES WARM BASED ICE, WHY? CLASSIC U-SHAPED VALLEY U IMPLICATIONS FOR EROSION INTENSITY

  21. PLUCKING….

  22. PLUCKING IN ACTION

  23. ABRASION -STRIATIONS AND POLISH

  24. ABRASION TAKES TOOLS

  25. “THE DIRT MACHINE” GLACIERS AS A CONVEYOR BELT FOR ROCK DEBRIS

  26. WHERE DOES ERODED MATERIAL GO? MORAINE FORMATIONINDICATES A STILL STAND

  27. MORAINES LATERAL TERMINAL LATERAL

  28. Frans Joseph Glacier - Tom Lowell

  29. MASSIVE COASTAL MORAINES

  30. MORAINES ARE SCARCE IN INTERIOR NEW ENGLAND -- IMPLIES RAPID, DYNAMIC ICE MARGIN RETREAT (KOTEFF AND PESSL)

  31. OUTWASH PLAINS FROM WATER CARRIED DEBRIS

  32. PRESENT DAY OUTWASH -- MT COOK

  33. SEDIMENT DELIVERY TO ICE MARGINAL LAKES

  34. LAKE SEDIMENTS

  35. TASMAN GLACIER

  36. TILL - NOT WELL WASHED BY WATERBASAL VS MELTOUT SIERRA NEVADA, ALPINE CENTRAL MASS, CONTINENTAL

  37. ESKER

  38. DRUMLIN - STREAMLINED FEATURE

  39. KETTLED TERRAIN

  40. KETTLE FORMING TODAY