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Cryosphere (Frozen water). The shape of ice crystals cause ice to be less dense than liquid water This causes Ice to float with about 9% of the ice volume.

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Presentation on theme: "Cryosphere (Frozen water). The shape of ice crystals cause ice to be less dense than liquid water This causes Ice to float with about 9% of the ice volume."— Presentation transcript:

1 Cryosphere (Frozen water)

2 The shape of ice crystals cause ice to be less dense than liquid water This causes Ice to float with about 9% of the ice volume above water (91% below). A.k.a. the Tip of the iceberg.

3 Time scales relevant to the cryosphere

4 87% of ice is in Antarctica 10% Greenland 2.5% ice shelves (mostly Antarctic) If all Ice melted sea levels would go up by about 65 meters (213 ft)

5 Snow cover Essential for water resources in the western US Roughly 75% of the Western US fresh water supply comes from snow pack.

6 Dendrite: Common six sided ice crystal / snow flake.

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8 January or February have most NH snow cover.

9 Aside from Antarctica the SH has very little snow cover.

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13 River and lakes Spring thaw

14 Most rivers are thawing earlier and freezing later.

15 Alpine Glaciers Milk Lake glacier 1988 Milk Lake 2009

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17 Glaciers around the world are in retreat

18 Permafrost

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23 Methane possibly released from permafrost?

24 Methane change Since 2005

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27 Land Ice

28 From Grace See andhttp://www.aber.ac.uk/greenland/Massbalance.html Gravity Recovery And Climate Experiment Right: Mass change distribution ( ) across the ice sheet as determined by GRACE observations.

29 Land Ice

30 Ablation: Melt, sublimation, loss from wind, loss from flow Equilibrium line: Accumulation = Ablation

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32 2010 was an exceptional year for Greenlands ice cap. Melting started early and stretched later in the year than usual. Little snow fell to replenish the losses. By the end of the season, much of southern Greenland had set a new record, with melting that lasted 50 days longer than average.

33 350 Gt – 1 mm sea level rise Both Antarctica and Greenland have been losing ice over the past 8 years.

34 Ice flow speed increase with distance above ground Side view

35 Top view: Ice flow increases with distance from valley walls.

36 Basal melt can provide a lubricant to increase total ice flow.

37 Ice flow increases with increasing tilt of the mountain

38 Air bubbles trapped in ice can reveal atmospheric composition in the past (up to about 600,000 yrs).

39 When accumulation is greater than ablation in a certain zone the ice sheet : a)Grows b)Shrinks c)Stays the same size Sublimation or calving

40 When accumulation is greater than ablation in a certain zone the ice sheet : a)Grows b)Shrinks c)Stays the same size Sublimation or calving

41 Sea Ice What happens to the water level when the ice melts? a. Overflows b. Goes down c. Stays the same

42 Sea Ice What happens to the water level when the ice melts? a. Overflows b. Goes down c. Stays the same

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44 From: The yellow outline on each image shows the median sea ice extent observed by satellite sensors in September and March from 1979 through 2000.

45 Sept 2011

46 From:

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