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[music]

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Greetings from Punta Arenas, our base of operations for the Antarctic campaign of NASA’s Operation IceBridge.

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Punta Arenas is the capital of Chile’s southern region

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and one of the main jumping off points for Antarctica.

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Behind me there’s a replica of the lifeboat James Caird,

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which the Antarctic explorer Ernest Shackelton used to escape Elephant Island

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after his ship, Endurance, sank in the Weddell Sea.

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The spirit of this explorer is an inspiration to IceBridge, which is dedicated

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to exploring remote areas of Antarctica to observe changes to the ice sheet

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covering the continent and the sea ice surrounding it.

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It takes between three and four hours to reach Antarctica from southern Chile.

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Since flights are longer than those of the Arctic campaign, we use

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another type of plane, a DC-8, which can carry larger quantities

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of fuel and thus lets us reach very remote areas of the frozen continent.

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This is the fourth year that IceBridge has explored Antarctica, since the

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mission began in 2009. In total, there are sixteen missions planned for

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for this campaign: twelve will study land ice and the remaining four

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will observe the ice floating on the seas of Weddell, Bellingshausen and Amundsen, in the

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the western sector of the continent. IceBridge uses several instruments to study

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sea ice. On one hand, a laser measures the freeboard,

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or the height of the ice floe above the water surface. On the other hand, one of the radars

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radars onboard the DC-8, assisted by the laser, measures the snow layer

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accumulated over sea ice. The combination of the two

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data sets allows scientists to calculate the total thickness of sea ice

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including the fraction that is under water. Finally, a high-definition

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camera system takes images that will help researchers locate leads between ice floes.

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The areas of land ice of greatest interest to IceBridge

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are located in the west coast of Antarctica, where

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the largest changes are taking place. One of the glaciers that is most quickly

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losing ice to the sea is Pine Island Glacier, southwest of the Antarctica Peninsula.

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During the 2011 campaign, IceBridge discovered

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a huge crack that crossed Pine Island’s ice shelf

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almost entirely.  It's thought that when it breaks,

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it will create an enormous iceberg the size of Manhattan.

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But when NASA’s DC-8 visited Pine Island Glacier again in 2012,

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, the crack was still there, only wider and with a secondary crack.

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And so the iceberg remains for now.

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Meanwhile, the data collected by IceBridge instruments

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over Pine Island and the neighboring Thwaites Glacier

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will allow researchers to revisit previous years’ measurements and determine

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how the ice flow is evolving in that corner of Antarctica.