City-Sized Ice Shelf Breaks Free Of Antarctica

LeadSongDog writes "Germany's TerraSAR-X satellite is showing that the Antarctic's Pine Island ice shelf has calved a 'berg of 720 square kilometres, 'the size of Hamburg.' Angelika Humbert says 'The Western Antarctic land ice is on land which is deeper than sea level. Its "bed" tends towards the land. The danger therefore exists that these large ice masses will become unstable and will start to slide.' The article extrapolates that 'If the entire West Antarctic ice shield were to flow into the Ocean, this would lead to a global rise in sea level of around 3.3 meters.' Goodbye Florida.

Re:what?

[Entropius]

I think the point is that the boundary between the ice and the rock is below sea level.

Re:what?

[Microlith]

Wait what?

Umm.. isn't it impossible to have land that isn't deeper than sea level?

By definition, that is land. My guess is that you meant to ask if it is impossible to have land below sea level, and the answer is no. Much of New Orleans and Death Valley in the US are below sea level, they just happen to be surrounded by natural (and some artificial) barriers that keep the water out.

My understanding of the point is that the ice in question is standing on solid land below the ocean's surface, which means that its volume is not currently reflected by the height of the oceans today. In addition, the land is sloped towards the rest of the ocean so, should the ice in question calve off it will enter the ocean rather than simply cracking but staying put.

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[account_deleted]

Comment removed based on user account deletion

Re:Goodbye Florida...

[CrimsonAvenger]

...hello beach front property in Alabama!

Ever hear about Mobile, Alabama?

Hint: Alabama already has a Gulf Coast....

Re:Sigh... Again?

[Anonymous Coward]

Every year we get at least one or two pieces of ice breaking from the main shield. Happens at both poles. It's normal.

True. What's not normal is the amount of ice breaking away. Pine Island and Thwates glacier are speeding up. They're calving more ice into the ocean than before. Sure they calved before, but not as much or as often.

Re:No such thing as 'man made global warming'

[RenderSeven]

FTFA (which you should have read before posting): Are ice breaks caused by climate change? Angelika Humbert does not so far see any direct connection: "The creation of cracks in the shelf ice and the development of new icebergs are natural processes", says the glaciologist. Not arguing one way or the other, but the FTFA says its not related.

Re:what?

[H0p313ss]

I also wonder if a big piece (like say a few cubic km) of ice slides in the water at few km/h. a really big tsunami ?

Yes, if that were to happen the result would be quite dramatic. But the chunk we're talking about is the leading tongue of an ice shelf that is already floating at sea level and the crack that caused this calving has been tracked since 2011 so it's not exactly a dramatic change as the media would like you to believe.