GLACIATIONBob Carson

June 2007

Spitsbergen photo by Ben Schupack

SNOW

GRAUPEL

American Scientist

SNOWFIELDSARE NOT GLACIERS

MOUNT ST. HELENS 17 MAY 2007

Photo by Jonathan Loeffler

GLACIERS

MOUNT OLYMPUS

MOUNT HAYES, ALASKA RANGE, AUSTIN POST

GLACIER VELOCITY

STAGNANT: TOO THIN OR SURFACE SLOPE TOO GENTLE

POLAR (COLD-BASED): FLOW ONLY (FROZEN TO BED)

TEMPERATE (WARM-BASED): FLOW AND SLIP

SURGING: MELTWATER REDUCES FRICTION

GLACIER BAY

STAGNANT GLACIER

MOUNT EVEREST

POLAR GLACIER

Antarctica photo by Clare Carson

TEMPERATE GLACIER

MOUNT OLYMPUS

THE SOLE OF A GLACIER

SOUTH SAWYER GLACIER, AUSTIN POST

SURGING GLACIER

ST. ELIAS MOUNTAINS

PETERS GLACIER PHOTO BY PAUL SHEARER

30-60% of Svalbard glaciers surge

Fridtjofbreen, Bellsund, Spitsbergen Photo M. J. Hambrey

GLACIER MASS BALANCE

• ACCUMULATION > ABLATION: MARGIN ADVANCES

• ACCUMULATION = ABLATION: EQUILIBRIUM (MORAINE BUILDING)

• ACCUMULATION < ABLATION: MARGIN RETREATS (GLACIER DOES NOT DEFY GRAVITY)

SOUTH CASCADE GLACIER, 1957,

AUSTIN POST

THE EARTH’S NEWEST GLACIER IS

ADVANCING

MOUNT ST. HELENS, 17 MAY 2007

GLACIER IN EQUIBRIUM in mid 1800s

Athabasca Glacier by Ward’s

MOST OF THE EARTH’S GLACIERS ARE RETREATING

TIERRA DEL FUEGO

GLACIER SIZE AND SHAPE

Spitsbergen photo by Ben Schupack

CIRQUE GLACIERS AND CIRQUES

TETON RANGE

CIRQUES

HANGAY MOUNTAINS

TARNS

Katahdin photo by Tim Wood

VALLEY GLACIERS AND GLACIAL TROUGHS

ALTAI MOUNTAINS

GLACIAL TROUGHS

ALTAI MOUNTAINS STEENS MOUNTAIN

GLACIAL TROUGH LAKES

Sierra Nevada photo by Steve BrownWATERTON LAKE

FJORDS

Baffin Island photo by Taylor Johnson

FJORDS

www.kingsleighinn.com/images/SomesSound

WHY ARE FJORDS SO DEEP?

• SEA LEVEL FLUCTUATION = 120 m

• DENSITY ice = 90% DENSITY water

TRACY ARM, AUSTIN POST

folk.uio.no

www.caingram.info

SOGNE FJORD 1308m

www.rosssea.info Skelton Glacier

SKELTON INLET 1933m

MOUNTAIN ICE CAPS

http://www3.eou.edu/geology/wallowalake

Glacier

MOUNTAIN ICE SHEETS

MOUNTAIN ICE

SHEETS

geoscape.nrcan.gc.ca/.../images

WATERVILLE PLATEAU

LAKE CHELAN

CONTINENTAL ICE SHEETS

www.crystalinks.com/antarctica_satellite

CONTINENTAL ICE SHEETS

Greenland photo by George Linkletter

Greenland photo by Art Rempel

Greenland photo by George Linkletter

ICE SHELVES

www.mbari.org/benthic/tour1.htm ROSS ICE SHELF

LARSON ICE SHELFCOLLAPSED IN 1995

svs.gsfc.nasa.gov/vis/a000000/a001400/a001400/

1992 1997

SEA ICE (NOT A GLACIER)

Antarctica photo by Seth White

SEA ICE

Scott Polar Research Institute

ICEBERGS (NOT GLACIERS)

GREENLAND

ICEBERGS

Antarctica photo by Clare Carson

PROCESSES• ICE: ABRASION, PLUCKING,

DEPOSITION

• MELTWATER: CORRASION, ABRASION, DEPOSITION

• MASS WASTING

MOUNT EVEREST

OTHER EROSIONAL LANDFORMS

BEARTOOTH MOUNTAINS

POLISH

VANCOUVER ISLAND

STRIATIONS

LAKE CHELAN

GROOVES

VANCOUVER ISLAND

ROCHES MOUTONEES

BEARTOOTH MOUNTAINS

ARETES

WALLOWA MOUNTAINS

HORNS

ABSAROKA MOUNTAINS

COLS

TETON RANGE

HANGING VALLEYS & TRUNCATED SPURS

BEARTOOTH MOUNTAINS

GLACIER DEPOSITION

FRANZ JOSEF GLACIER

TILL

PUGET LOWLAND

MORAINES

MOUNT EVEREST

TERMINAL MORAINES

LATERAL MORAINES

MEDIAL MORAINES

Denali photo by George Stephens

ALTAI MOUNTAINS

ICE STAGNATION LANDFORMS

RONGBUK GLACIER

KETTLES

MOUNT RAINIER

ESKERS

WATERVILLE PLATEAU

FRANZ JOSEF GLACIER

KAMESMENDENHALL GLACIER

MELTWATER

EMMONS GLACIER

OUTWASH

PUGET LOWLAND

OUTWASH PLAIN

EMMONS GLACIER

PAYETTE LAKE

GLACIER EXTENT 18-20,000 YEARS AGO

images.encarta.msn.com

NORTHWEST EUROPE GLACIATION 18-20,000 YEARS AGO

SVENDSEN ET AL. 2004

GLACIER EXTENT TODAY

THANK YOU!BEN SHUPACK

WHITMAN ’07 ON SPITSBERGEN