Yates had a history of postpartum psychosis, major depression and two suicide attempts before she drowned her children and laid their bodies on her bed, covering them with a sheet.

CNN: Andrea Yates case: Expert: Mom believed she was battling Satan

It is this humanity to her work that has made her popular, such as covering a bed in a hessian before casting it, so as to give it a "hairy" texture.

BBC: Whiteread's 'hands-on' approach

So by firing radio pulses through the overlying sheet and recording the return echoes, scientists can plot both the depth of the rock bed and - by definition - the thickness of the ice covering.

BBC: Antarctic ice volume measured