Re: Huge Antarctic ice chunk collapses

Hi Nadia,

  You nailed it 100% when you started to identify the force acting on the ice!  The force is gravity!  Heat, in the sense you're referring to it, would not have caused the ice to fracture.  Heat would have caused a trivial about of warming of the surface of the ice.

  What we see in the satellite images is a progressive cascading series of fractures of the glacier.  Remember the ice consists of nearly pure H20 crystals and interstitial brine.  It takes very little energy to cleave the crystals, and the cracks penetrate at high speed.

The brine also acts to lubricate the massive sections of ice as they calve off into the ocean.  Each chunk creates waves as it  enters the ocean, and alters the stress patterns in the shelf.  The combination of alternating strains and shifting stresses cause the entire mass to 'granulate' in a manner similar to the shattering of tempered glass.

I'm certain that no one who has ever seen tempered window shatter at an impact would assert the melting point of the window was a significant factor in the failure.