Catastrophic flood - Glacial Lake Missoula

Giant ripple marks from catastrophic flood

Ice shelves - what are they? How do they form?

Why are they important?

Ice shelves - what are they? Floating icesheet - form in center of continent and move out under own weight

Why are they important? Hold back glaciers/icesheets

What has happened recently to ice shelves?

Which would bemost vulnerable?

Larsen Ice shelfGone 2002Wilkins

2008

1/31/02

Larsen B IceShelf, Antaractic Peninsula

2/17/02

2/23/02

Adelie penguin populationsare declining abruptly in the Antarctic Peninsula, where populations of other penguins occurring farther north aregrowing

From National Geographic, 9/04, p. 17