CONTINENTAL ICE SHEET GREENLAND ALPINE ICE VALLEY GLACIERS

CONTINENTAL ICE SHEET GREENLAND

ALPINE ICE- VALLEY GLACIER(S)

GLACIER BAY, ALASKA

ALL GLACIERS HAVE TWO ZONES ACCUMULATION = + MASS ABLATION = - MASS

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

GAME OF MASS BALANCE SNOW IN vs WATER/ICE OUT

IDEALIZED MOTION- CROSS SECTION

GLEN’S FLOW LAW e= strain rate A = constant related to ice temperature rgh shear sin astress (? ) t= basal n = exponent with an average value of 3

TEMPERATURE MATTERS Does cold or warm ice strain more rapidly?

STRESS-STRAIN RESPONSE (DEBRIS FLOW) (WATER)

MASS FLUX - BIRD’S EYE VIEW

VELOCITY DISTRIBUTION BIRD’S EYE

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

WHAT IS THE TEMPERATU RE AT THE BASE OF THE ICE? GEOTHERMA L -FRICTION

WARM BASED ICE sliding along bed

FOX GLACIER, New Zealand

COLD-BASED ICE frozen to bed

DRY VALLEY AREA-ANTARTICA

COMPARE, WARM VS COLD

U CLASSIC USHAPED VALLEY EROSION REQUIRES WARM BASED ICE, WHY? IMPLICATIONS FOR EROSION INTENSITY

PLUCKING….

PLUCKING IN ACTION

ABRASION -STRIATIONS AND POLISH

ABRASION TAKES TOOLS

DIRT MACHIN E” GLACIERS AS A CONVEYOR BELT FOR ROCK DEBRIS

WHERE DOES ERODED MATERIAL GO? MORAINE FORMATION INDICATES A STILL STAND

MORAINES AL R E T LA TERMINAL T A L L A R E

Frans Joseph Glacier - Tom Lowell

MASSIVE COASTAL MORAINES

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

OUTWASH PLAINS FROM WATER CARRIED DEBRIS

PRESENT DAY OUTWASH -- MT COOK

SEDIMENT DELIVERY TO ICE MARGINAL LAKES

LAKE SEDIMENTS

TASMAN GLACIER

SIERRA NEVADA, ALPINE TILL - NOT WELL WASHED BY WATER BASAL VS MELTOUT CENTRAL MASS, CONTINENTAL

ESKER

DRUMLIN - STREAMLINED FEATURE

KETTLED TERRAIN

KETTLE FORMING TODAY